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20 September 2020, Volume 47 Issue 9
Biotechnology
Prediction and Bioinformatic Analysis of miR-107 Target Genes in Jingyuan Chickens
YU Baojun, HE Jintong, YAO Tingting, WU Hao, FAN Xiya, HU Honghong, WANG Weizhen, GUO Ju, GU Yaling, CAI Zhengyun, XIN Guosheng, ZHANG Juan
2020, 47(9):  2695-2705.  doi:10.16431/j.cnki.1671-7236.2020.09.001
Abstract ( 267 )   PDF (1678KB) ( 166 )  
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To explore the regulatory mechanism of miR-107 in the process of inosine acid specific deposition of muscle tissue in Jingyuan chickens,the bioinformatics software and databases were used to bioinformatically analyze and predict target genes of miR-107 in Jingyuan chickens in this study.The transcriptome sequencing technology was used to obtain the sequence of miR-107 in Jingyuan chickens,perform sequence alignment and analyze its conservation.TargetScan,miRDB and PicTar were applied to predict target genes of miR-107.The intersection of the three results and validated targets from miRTarbase database were demonstrated by Gene Ontology and signal pathway enrichment analysis using OmicShare tool,and discussed the expression level of miR-107 in different tissues and diseases in HMED database.The results showed that miR-107 sequence of Jingyuan chickens was highly conserved among all species,and the biological functions of target genes regulated by miR-107 mainly included basic biological function,such as cellular processes,biological regulation,metabolic processes,response to stimulus and molecular functions were enriched in binding,catalytic activity,transcription regulator activity and so on.Target genes existed in various components of the cell,including organelles,cell membranes and protein-containing complexes.The signal transduction pathway was significantly enriched in the microRNAs in cancer,human papillomavirus infection,pathways in cancer and PI3K-Akt signaling pathway (P<0.05).miRNA-target gene interaction analysis found that miR-107 mainly inhibited the expression of target genes through targeted binding to the untranslated region of the target gene mRNA.According to the expression data of miR-107 in different tissues and diseases in the HMED database,it was found that the expression level of miR-107 was the highest in melanoma,and was lower in tonsil,muscle and other tissues.The prediction and bioinformatics analysis of miR-107 target genes provided a reference for in-depth study of the function and regulatory mechanism,and laid the basis to study the role of miR-107 of muscle development in Jingyuan chickens.
Selective Signal Analysis of Langshan Chickens Based on RAD-seq
ZHU Yunfen, YIN Jianmei, ZHANG Jifa, LI Guohui, SHEN Haiyu, XUE Qian, ZHANG Huiyong, DOU Xinhong, SU Yijun, HAN Wei
2020, 47(9):  2706-2714.  doi:10.16431/j.cnki.1671-7236.2020.09.002
Abstract ( 218 )   PDF (1435KB) ( 170 )  
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To identify characteristic genes of Langshan chickens through genome selection signal testing,RAD-seq simplified genome sequencing technology was employed to identify SNP markers in Langshan and other 18 indigenous chicken breeds.The genetic structure and selected genes were analyzed by constructing phylogenetic tree and testing genome selective signals.The results showed that 320 874 SNPs were identified in Langshan chickens.In general,19 indigenous chicken breeds were grouped into five clusters,which were consistent with the breeding history and geographical distribution.In total,46 selected areas and 122 genes in Langshan chickens were identified through ZHp signal testing (ZHp<-3.5).Among these areas,some were also selected in WH(15 areas),BJ(14 areas),DG(11 areas) and BY((13 areas)) chickens.GO and KEGG function analysis showed that the 122 selected genes in Langshan chickens were mainly enriched in hemopoiesis,regulation of transcription,eosinophil chemotaxis and ossification processes,and adrenergic signaling in cardiomyocytes,Toll-like receptor signaling pathway,calcium signaling pathway,cytosolic DNA-sensing pathway and NOD-like receptor signaling pathway,respectively (P<0.05).The selection mainly functioned on shaping characters of stimulus-response,innate immunity,metabolism as well as nervous system development in Langshan chickens.The results could provide important genetic information for evaluation,conservation and utilization of Langshan chickens.
Cloning,Expression Analysis and Regulation of PNPLA8 Gene by Prolactin in Buffalo
MA Xiaoya, PANG Chunying, LU Xingrong, DUAN Anqin, LIANG Shasha, LIANG Yanyin, DENG Tingxian, LIANG Xianwei
2020, 47(9):  2715-2723.  doi:10.16431/j.cnki.1671-7236.2020.09.003
Abstract ( 185 )   PDF (2013KB) ( 96 )  
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In order to investigate the role of patatin-like phospholipase domain-containing 8(PNPLA8) in lipid metabolism of mammary gland in buffalo,the coding region (CDS) was amplified and cloned by PCR based on the sequence of Bos taurus PNPLA8 gene in GenBank (accession No.:XM_005205444.4) were analyzed using bioinformatics software.Total RNA was extracted from different tissues of buffalo and mammary glands,which were harvested from different lactating buffaloes.The expression of PNPLA8 gene mRNA in different tissues and different lactation period was detected by Real-time quantitative PCR.For buffalo mammary epithelial cell treatment,different concentrations of prolactin were used and the effect of prolactin on the expression of PNPLA8 gene was detected by Real-time quantitative PCR.The results showed that the length of the PNPLA8 gene CDS was 2 355 bp,encoding 784 amino acids.The sequence showed high homology with Bos mutes and Capra hircus.PNPLA8 gene was expressed at different levels in 11 tissues examined,with a relatively high level in the lung and mammary tissues while the low level in the fat and muscle tissues.The expression abundance of the PNPLA8 gene was variable during lactation and showed a trend of "low-high-low".Prolactin treatment showed that the expression of PNPLA8 gene decreased with the increase of prolactin concentration.In this study,PNPLA8 gene of buffalo was successfully cloned,and the expression of PNPLA8 gene in different tissues and the lactation period was analyzed.Herein,the effect of prolactin on the expression of PNPLA8 gene was studied that laid a foundation for further research on PNPLA8 gene of mammary gland in buffalo.
Isolation and Identification of Goat Dermal Papilla Cells and Expression of TGF/β-smad Pathway Related Genes
DING Yangyang, ZHAO Huijing, GUAN Weijun, HE Xiaohong, PU Yabin, JIANG Lin, MA Yuehui, ZHAO Qianjun
2020, 47(9):  2724-2731.  doi:10.16431/j.cnki.1671-7236.2020.09.004
Abstract ( 171 )   PDF (7315KB) ( 52 )  
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The purpose of this study was to isolate goat hair follicle cells,and to explore the expression of TGF-β/smad pathway-related genes,providing a good model for the research on the mechanism of goat hair follicle development in vitro.In this study,two steps of neutral protease and collagenase digestion were used to treat the skin on the back of goats,the hair follicle cells were isolated and purified under stereomicroscope.Cellular immunofluorescence and Western blotting method were used to verify the expression of α-SMA (α-smooth muscle actin,α-SMA) and VIM (vimentin,VIM),and the expression of related genes of the TGF-β/smad pathway in goat hair papilla cells were examined.The results showed that the isolated goat hair follicle cells in adherent culture after separation grew slowly and had mature morphology after 15 days of separation and could be subcultured.The results of immunofluorescence and Western blotting showed that both α-SMA and VIM were positive in vitro cultured hair papilla cells.The expression of smad4 and smad5 genes in the TGF-β/smad pathway were significantly higher than those in control group (P<0.05),and the expression of smad2,smad6,and smad7 were extremely significantly higher than those in control group (P<0.01).These key genes related to hair follicle development were highly expressed.This study successfully isolated goat dermal papilla cells,which would give a good theoretical basis and cell model for studying the hair follicle development mechanism in vitro.
Transcriptome Analysis of Hybrid Sturgeons Intestinal Infected with Plesiomonas shigelloides
ZHANG Mingyang, ZENG Maoqin, LIU Yanhan, ZHANG Piao, YANG Xia, YANG Ying, WEN Guilan, CHENG Zhentao, JIANG Haibo, WEN Ming
2020, 47(9):  2732-2740.  doi:10.16431/j.cnki.1671-7236.2020.09.005
Abstract ( 226 )   PDF (1777KB) ( 60 )  
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In order to explore the changes of intestinal transcriptome of sturgeons infected with pathogenic bacteria,the hybrid sturgeons about 360 d were infected by Plesiomonas shigelloides,and their intestinal tissues were collected after 24 h of inoculation and used for extraction of mRNA,and transcriptome sequencing was performed using high-throughput sequencing technology and analyzed for GO function classification and KEGG signal pathway.The results showed that there were 13 542 of differentially expressed genes with 9 774 of up-regulated genes and 3 768 of down-regulated genes in the hybrid sturgeon intestinal comparing with the control group.GO analysis found that significantly enriched sturgeons gut differentially expressed genes were mainly involved in immune system process,immune effect process and stimulation response.Significant enrichment of molecular functions mainly included:DNA binding,signal receptor activity,nucleic acid transcription factor activity.The cell components were mainly extracellular,extracellular components,cell membrane.KEGG analysis showed that the immune signaling pathways involved in differentially expressed genes in sturgeons intestinal were RIG-Ⅰ-like receptor signaling pathway,Toll-like receptor signaling pathway and cytosolic DNA-sensing pathway.These results laid a good foundation for the defense molecular mechanism of the hybrid sturgeon against pathogenic infection.
Physiology and Biochemistry
Comparison of the Distribution of PGP9.5 and NPY in Cryptorchidism and Testicular Tumors in Dogs
REN Jianming, WEI Yanming, YUAN Ligang, WANG Qianmei, LI Chengye
2020, 47(9):  2741-2750.  doi:10.16431/j.cnki.1671-7236.2020.09.006
Abstract ( 192 )   PDF (48008KB) ( 43 )  
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The purpose of this study was to analyze the distribution and expression of peptidergic neurotransmitters protein gene product 9.5 (PGP9.5) and neuropeptide Y (NPY) in cryptorchidism and testicular tumors of dogs,compare them with normal testicular tissues of the same age,and provide reference for clinical diagnosis of malignant transformation in testicular tumors of dogs.HE staing,Masson trichrome staining,Gomori silver staining and toluidine blue staining were used to observe the tissue characteristics of reticular fibers,collagen fibers and mast cells.Immunohistochemical SP method and immunofluorescence combined with IPP were used to analyze the expression and localization of PGP9.5 and NPY in tissues.The results showed that the seminiferous epithelium of normal dog testis was composed of 4-7 layers of spermatogenic cells and Sertoli cells,and the distribution of collagen fibers and reticular fibers in interstitial tissue was sparse.The thickness of collagen fibers in the basement membrane of cryptorchidism seminiferous tubules increased,the nucleus of Sertoli concentrated at the base of seminiferous tubules,and the interstitial reticular fibers increased.The tissue structure of testicular tumor was unclear,collagen fibers and reticular fibers were irregularly distributed,and mast cells increased significantly compared with normal and cryptorchid groups.The immunofluorescence results showed that PGP9.5 was moderately positive in Leydig cells of normal testis,no significant expression in spermatogenic cells,strongly positive in Leydig cells and spermatogenic cells of cryptorchidism,and occasional expression in testicular tumors.NPY was occasionally expressed in normal testicular Leydig cells,but not in spermatogenic cells,strong positive expression in Leydig cells and seminiferous epithelium of cryptorchidism,high density and strong positive expression in interstitial vessels,and no obvious expression in testicular tumors.Immunohistochemical statistics showed that the expression of PGP9.5 and NPY in testicular tumor tissue were extremely significantly lower than that in normal group (P<0.01),while the expression of PGP9.5 and NPY in cryptorchidism group were significantly or extremely significantly increased (P<0.05;P<0.01).Therefore,the expression of PGP9.5 and NPY in cryptorchidism of dogs was increased suggesting that the cryptorchidism of dogs had a tendency to develop into a tumor,and was related to the degree of malignant transformation of tumor.
Isolation,Culture and Identification of Testis Sertoli Cells in Mongolian Horses in vitro
SONG Lianjie, CUI Yingying, ZHAO Yiping, BAI Dongyi, REN Xiujuan, TE Rigele, DUGARJAVIIN Manglai, LI Bei
2020, 47(9):  2751-2758.  doi:10.16431/j.cnki.1671-7236.2020.09.007
Abstract ( 216 )   PDF (1963KB) ( 67 )  
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To study a simple and rapid separation of testis Sertoli cells in Mongolian horses and ensure their activity,the testis tissue of two-year-old Mongolian horses was mechanically isolated under a low temperature environment in this experiment,and 1-3 g of testis tissue was chopped,the free red blood cells and interstitial cells were removed by gravity precipitation method.0.1% collagenase Ⅳ and 0.25% trypsin-EDTA were used for tissue digestion, and cells were cultured in medium containing 10% fetal bovine serum.After inoculation,the purified Sertoli cells were isolated and purified by differential sticking method,and the impurity cells were removed by Tris-HCl infiltration method,and were identified by alkaline phosphatase (AKP) staining,HE staining and Real-time quantitative PCR.The results showed that most of the cells began to adhere to the wall after culture 24 h,and the shape of the cells was oval.After culture 48 h,the cytoplasm increased and the refraction became stronger.After culture 3-4 d,the cytoplasm of the cells expanded into tight junction.At this time,the cells were triangular with obvious nucleoli.After culture 6-7 d,the cells entered the stable phase.Real-time quantitative PCR results showed that the expression of GATA4 and GDNF genes were extremely significantly expressed in cultured cells (P<0.01).AKP staining supported the negative expression in Sertoli cells,indicating that the isolated cultured cells were indeed Sertoli cells.In this experiment,tissue was treated by mechanical separation and two-step enzyme digestion,and testicular support cells were obtained quickly and efficiently,the method of culturing Sertoli cells in Mongolian horses testis in vitro was successfully constructed.
Comparison of Lipid Profiles of Backfat and Inguinal Subcutaneous White Adipose Tissue from Acute Cold-treated Bama Pigs
PAN Jianfei, ZHENG Qiantao, TAO Cong, ZHAO Jianguo, WANG Yanfang
2020, 47(9):  2759-2766.  doi:10.16431/j.cnki.1671-7236.2020.09.008
Abstract ( 235 )   PDF (1163KB) ( 99 )  
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This experiment aimed to study the difference of lipid metabolism between backfat and inguinal subcutaneous white adipose tissue (iWAT) after acute cold exposure (4 ℃ for 4 h).The LC-MS/MS based lipidomics of backfat and iWAT from chow diet-fed and cold-treated six-month-old male Bama pigs were profiled.The results showed that the content of 4 lipids classes,including neutral lipids,free fatty acids,phospholipids and sphingolipids were varies greatly in iWAT of Bama pigs.The highest lipid class in both iWAT and backfat was neutral lipids,which accounted for 97.43% and 98.53% respectively;The lowest lipid class was sphingolipids,which accounted for 0.10%and 0.07% in iWAT and backfat,respectively.Among 16 subclass lipids,the highest content in iWAT and backfat was TAG,which accounted for 95.97% and 97.33%,respectively,while the lowest content was PA,which accounted for 3.98E-04% and 1.13E-04% in iWAT and backfat,respectively.PCA analysis showed that backfat and iWAT could be separated clearly,which indicated the distinct changes in lipid composition of both fat tissues.And 18 different lipid species were determined using a criteria of fold change>1.5 and P<0.05,the results showed that 16 lipid species were significantly downregulated in backfat,including 14 TAGs,DAG32:1 (16:1/16:0) and PE40:6p.Two lipid species,including CL74:8(18:2) and TAG54:3 (16:0),were observed to be upregulated in backfat.The above results indicated that TAG was the main content of iWAT in Bama pigs,the backfat and iWAT had different physiological responses for acute cold stimulation.
Effects of Inhibition of Different Rumen Microbial Activity on Rumen Fermentation and Fatty Acid Metabolism in Buffaloes
LI Mengwei, PENG Lijuan, PENG Kaiping, XIE Fang, LIANG Xin, GUO Yangxia, YANG Chengjian
2020, 47(9):  2767-2778.  doi:10.16431/j.cnki.1671-7236.2020.09.009
Abstract ( 176 )   PDF (950KB) ( 74 )  
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This study was aimed to evaluate the effects of inhibiting rumen bacteria,fungi and protozoa with adding linoleic acid and linolenic acid on in vitro rumen fermentation and fatty acid metabolism in buffaloes.Both fatty acids were supplemented with substrate and roughage (3:7) at the rate of 3% on dry matter (DM) basis in an in vitro batch culture system,there were 5 repetitions for each group.At the same time,four groups were set up:Control group and inhibition groups of protozoa,bacteria and fungi.After 24 h of incubation,total gas production,CH4,pH,VFA,NH3-N,MCP and LFA concentrations were measured.The results showed that:①With the addition of linolenic acid,compared with control group,the gas production decreased significantly after inhibition the growth of bacteria and protozoa,CH4 production increased significantly after inhibition of the growth bacteria and fungi,and CH4 production decreased significantly after inhibition of the growth protozoa (P<0.05).With the addition of linoleic acid,compared with control group,the gas production decreased significantly after inhibiting the growth of bacteria,fungi or protozoa,and CH4 production was significantly lower than other groups after inhibition of protozoa (P<0.05).② After inhibiting the growth of bacteria,fungi or protozoa,the pH and MCP concentration were affected significantly with the addition of linolenic acid (P<0.05),there was no significant effect on NH3-N concentration with the addition of linoleic acid (P>0.05).③ Compared with control group,the content of acetic acid and propionic acid was reduced significantly after inhibiting the growth of bacteria,fungi or protozoa (P<0.05).The butyric acid was reduced significantly after inhibiting the growth of bacteria with the addition of linolenic acid (P<0.05).The butyric acid was reduced significantly after inhibiting the growth of bacteria,fungi or protozoa with the addition of linoleic acid (P<0.05).④ Compared with control group, the concentrations of C11:0, C12:0, C13:0, C14:0, C14:1n5, C15:1n5, C16:1n7, C16:0, C18:3n3, C18:2n6c, C18:0, C20:2n6, C20:3n6, C20:1, C20:3n3, C20:0, C21:0, C22:6n3, C22:2n6, C22:0 was reduced significantly after inhibiting the growth of bacteria with the addition of linolenic acid, the concentrations of C12:0, C13:0, C14:0, C15:0, C16:1n7, C16:0, C17:0, C18:3n6, C18:3n3, C18:2n6c, C18:1n9t, C18:0, C18:2(cis-9,trans-11), C18:2(trans-10,cis-12), C20:2n6, C20:1, C20:0, C21:0, C22:6n3, C22:0, C23:0, C24:1n9, C24:0 was reduced significantly after inhibiting the growth of bacteria with the addition of linoleic acid (P<0.05).The results revealed that the addition of linoleic acid and linolenic acid could significantly manipulate in vitro rumen fermentation parameters,CH4 yield and fatty acid composition after inhibiting the growth of bacteria,fungi or protozoa.Protozoa greatly contributed to total gas and CH4 production while bacteria significantly affected rumen fatty acid metabolism.
Animal Nutrition and Feed Science
Study on the Structure and Function of Fecal Microbiome Between Diarrhea and Healthy Calves
ZHANG Zijing, ZHU Xiaoting, LYU Shijie, JIN Lei, XU Jiawei, HUANG Yongzhen, LI Zhiming, WANG Xianwei, YU Xiang, YANG Shang, LI Jing, WANG Eryao, XU Zhaoxue, SHI Qiaoting
2020, 47(9):  2779-2788.  doi:10.16431/j.cnki.1671-7236.2020.09.010
Abstract ( 271 )   PDF (1729KB) ( 166 )  
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This study was aimed to identify some specific microbiota to indicate the calf diarrhea by exploring the differences of fecal microbiota composition and function between healthy and diarrhea calves.Fecal samples were collected from 10 diarrheal and 10 healthy Xianan calves and used to extract genomic DNA.Fecal microbial diversity was investigated by 16S rRNA Illumina MiSeq high-throughput sequencing technology.Biomarkers with statistical differences were obtained,the differentially functional genes were annotated between two groups.The results showed that the fecal microbial diversity of diarrhea calves was less than healthy calves.Compared with healthy calves,the abundance of Proteobacteria and Fusobacteria was significantly increased,while Spirochaetae was decreased in calves with diarrhea at phylum level (P<0.05).At genus level,the relative abundances of Escherichia-Shigella,Fusobacterium,Lactobacillus and Clostridium_sensu_stricto_1 exhibited increased calves with diarrhea,the relative abundance of uncultured_bacterium_f_Bacteroidales_S24-7_group,Alloprevotella and Prevotellaceae_NK3B31_group exhibited decreased in calves with diarrhea (P<0.05).The differentially functional genes in diarrheal calves were significantly reduced in bacterial translation,ribosomal structure and biogenesis by COG functional profiles analyzes.The KEGG pathways was analyzed,the pathways in diarrheal calves were significantly increased in carbohydrate metabolism,xenobiotics biodegradation and metabolism,whereas they significantly decreased in cell growth,death,replication,repair,translation and transcription (P<0.05).The dominant bacteria were analyzed and ten biomarkers were identified as indicator for evaluating calf diarrhea between diarrhea and healthy groups in this study.The results provided crucial references for future research on preventing and treating calves diarrhea.
Effects of Perilla Cake and Rapeseed Meal Instead of Soybean Meal in Diet on Apparent Digestibility and Nitrogen Metabolism of Beef Cattle
XIA Zhijun, SONG Yu, CHANG Weixue, ZAN Linsen
2020, 47(9):  2789-2798.  doi:10.16431/j.cnki.1671-7236.2020.09.011
Abstract ( 249 )   PDF (994KB) ( 97 )  
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The purpose of this experiment was to study the effect of perilla cake and rapeseed meal instead of soybean meal on the apparent digestibility and nitrogen metabolism of beef cattle.20 Qinchuan beef cattle of about 12 months old with similar weight and good health were selected and divided into 5 groups with 4 cattle in each group according to the univariate randomized block design.Five different protein feeds treatments were 31% soybean meal,36% rapeseed meal,14% perilla cake+24% rapeseed meal,28% perilla cake+12% rapeseed meal and 42% perilla cake,respectively.The experiment lasted 120 days,of which the pre-feeding period was 15 days and the trial period was 105 days.During the test,the daily intake of nitrogen,urine nitrogen and fecal nitrogen,the apparent digestibilities of dry matter (DM),organic matter (OM),neutral detergent fiber (NDF) and acid detergent fiber (ADF) of each test cow were determined.The results showed that:① The 42% perilla cake group had the highest nitrogen intake,and the 36% rapeseed meal group had the lowest nitrogen content,and the differences between the groups were not significant (P>0.05).The manure nitrogen in 36% rapeseed meal group was significantly higher than 28% and 42% perilla cake groups (P<0.05),and there was no significant difference with 31% soybean meal group and 14% perilla cake group (P>0.05).② The 42% perilla cake group had the highest sedimentary nitrogen,which was significantly different from other groups (P<0.05),and the 31% soybean meal group was significantly higher than 36% rapeseed meal group (P<0.05).③ The apparent digestibility of DM and ADF in 42% perilla cake group were significantly higher than those in 31% soybean meal group and 36% rapeseed meal group (P<0.05).There was no significant difference in apparent digestibility of DM,OM and NDF between 14% and 28% perilla cake groups (P>0.05).④ The content of urea nitrogen in 14% perilla cake group was significantly higher than 31% soybean meal group and 42% perilla cake group (P<0.05),and it was not significantly different from the 36% rapeseed meal group and 28% perilla cake group (P>0.05).The 31% soybean meal group had significantly higher nitrosate nitrogen content than 36% rapeseed meal group and 42% perilla cake group (P<0.05),and these three groups were significantly higher than 14% and 28% perilla cake groups (P<0.05).Allantoin nitrogen in 31% soybean meal group was significantly higher than 42% perilla cake group (P<0.05),and there was no significant difference from the other three groups (P>0.05).There was no significant differences in creatine nitrogen,microbial nitrogen predicted value,urea nitrogen/urine nitrogen,creatine nitrogen/urine nitrogen,and purine derivative nitrogen/urine nitrogen among all groups (P>0.05).In summary,in this test,when 42% perilla cake was used instead of 31% soybean meal in the concentrate,the beef cattle had the highest nitrogen deposition,which was 3.65 g/d higher than 31% soybean meal group.The apparent digestibility of DM,OM,NDF and ADF were 3.45%,2.22%,6.56%,and 10.98% higher than 31% soybean meal group,respectively.
Preparation of Pectin/Chitosan Synbiotic Microcapsules and Its Study on Simulated Gastrointestinal Environments and Storage Stability
CUI Naiyuan, GAO Qingshan, YAN Changguo, CUI Lianhua
2020, 47(9):  2799-2807.  doi:10.16431/j.cnki.1671-7236.2020.09.012
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Pediococcus acidilactici and inulin were used as wall cores,with pectin and chitosan as the shell material.The conditions of microencapsulation were optimized by analyzing the embedding rate,particle morphology,the mechanical strength,gastrointestinal tolerance in vitro and storage performance.The experimental group was divided into three groups:Free Pediococcus acidilactici group (PA),microcapsule group made by embedding Pediococcus acidilactici alone (PC(PA)MCs),synbiotic microcapsule group made by embedding inulin and Pediococcus acidilactici (PC(PA-I)MCs).The results showed that the appearance,particle size,mechanical strength and embedding rate of microcapsules were better when the mass concentration of pectin was 5 g/100 mL,the content of inulin was 25 mg/mL and the mass concentration of chitosan was 0.8 g/100 mL.Through the gastrointestinal tolerance test in vitro, it was found that PC(PA-I)MCs group was relatively stable in the artificial gastric juice in vitro (P<0.05).At the same time,it began to release rapidly in the artificial intestinal fluid in vitro at 30 min and it was almost completely disintegrated after 2 h.It was found that the cell survival rate of PA group decreased significantly at cold and room temperature through the storage test for 4 weeks.While the cell survival rate of PC(PA-I)MCs group decreased slightly.And the cell survival rate of PC(PA-I)MCs group was higher than that of PC(PA)MCs group (P>0.05).At room temperature,the cell survival rate of PC(PA-I)MCs group was higher than that of PC(PA)MCs group (P>0.05).In summary,pectin/chitosan microcapsules with inulin as probiotics had a better embedding effect on Pediococcus acidilactici.
Isolation,Identification and Its Suitable Degradation Conditions of a Zearalenone-degrading Bacteria
JIN Bowen, XU Changchun, LI Gen, LI Xiaoyu, WANG Lili, LI Jibin, XU Yongping
2020, 47(9):  2808-2815.  doi:10.16431/j.cnki.1671-7236.2020.09.013
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The aim of this study was to reduce zearalenone (ZEN) in feed by bio-degradation rapidly and effectively.A total of 70 samples of cow manure,sheep manure and soil were collected from different areas and then 164 strains were isolated from these samples.Cyclopentanone was used as the only carbon source to preliminarily screen the 164 strains isolated from the collected samples,and the second-screening was performed using zearalenone as the only carbon source.As a result,8 ZEN-degrading strains were obtained.The ZEN-degrading efficiency of 8 strains was determined by high performance liquid chromatography (HPLC),and a strain with high ZEN-degrading,namely NF-PJ-5 strain.The strain was identified as Sphingobacterium multivorum by 16S rDNA sequence comparison,phylogenetic tree construction,colony morphology observation and physiological and biochemical identification.The ability of NF-PJ-5 strain to degrade zearalenone at different temperature,different pH and different concentration of bacterial solution were studied.In addition,the mechanism of ZEN degradation by this strain was studied.The results showed that at 28-32 ℃,pH 6.5-7.5,and the concentration of bacterial solution above 2×109 CFU/mL,the strain could maintain a high degradation rate.Besides,the strain could degrade 83% ZEN with an initial concentration of 10 μg/mL,after 48 h culture at 30 ℃,pH 7.0,and a shaking speed of 160 r/min.From the above,a highly efficient ZEN-degrading strain was screened in this study,and it was identified as Sphingobacterium multivorum.It was preliminarily speculated that the strain could degrade ZEN by producing extracellular enzyme,and the cell wall of the strain had a certain adsorption capacity for ZEN.
Effects of Citrus Extract on Plasma Biochemical Indexes,Hormone Levels and Antioxidant Function of Broilers after Transport Stress
LI Zhenming, YU Miao, CUI Yiyan, RONG Ting, LIU Zhichang, DU Zongliang, MA Xianyong
2020, 47(9):  2816-2823.  doi:10.16431/j.cnki.1671-7236.2020.09.014
Abstract ( 175 )   PDF (882KB) ( 84 )  
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In order to study the effects of citrus extract on the plasma biochemical indexes,hormone level and antioxidant function of broilers after transport stress,a total of 360 twenty-eight-day-old fast-growing Yellow feather broilers were randomly divided into two groups (6 replicates per group,30 per replicate).The control group was fed basic diet without antibiotics,the experimental group was fed basic diet supplemented with 10 mg/kg citrus extract.At 63 days,six chickens were selected from each replicate for transport stress test for 0,2,and 4 h,respectively,and plasma sampling were conducted after transportation.The results showed that:① For glucose,cholesterol and urea nitrogen,there was a significant interaction between food treatment and transportation time (P<0.05).Compared with the control group,the contents of urea nitrogen and cholesterol in the plasma of broilers in the experimental group were significantly lower than that in the control group,and the content of glucose in the plasma of broilers in the experimental group was significantly higher than that in the control group (P<0.05).Transport stress significantly affected the content of urea nitrogen,cholesterol and glucose in the plasma of broilers in the control group,after transportation,the content of urea nitrogen and cholesterol increased significantly,while the content of glucose decreased significantly (P<0.05).② For corticosterone,triiodothyronine and thyroxine,there was significant interaction between food treatment and transport time (P<0.05).Compared with the control group,the content of corticosterone in the plasma of broilers in the experimental group was significantly lower than that in the control group,while the content of triiodothyronine and thyroxine in the experimental group was significantly higher than that in the control group (P<0.05).Transport stress significantly affected the content of corticosterone,triiodothyronine and thyroxine in the plasma of the control group,after transportation,the content of corticosterone in the plasma of the broiler significantly increased,while the content of triiodothyronine and thyroxine significantly decreased (P<0.05).③ For glutathione peroxidase,there was a significant interaction between food treatment and transportation time (P<0.05).Compared with the control group,the glutathione peroxidase activity in the plasma of broilers in the experimental group was significantly higher than that in the control group (P<0.05);Transport stress significantly affected the activity of glutathione peroxidase in the plasma of broilers in the control group.With the prolongation of transport time,the activity of glutathione peroxidase in the plasma of broilers decreased significantly (P<0.05).Therefore,transportation stress affected the metabolism level,hormone secretion and antioxidant function of Yellow feather broiler.Adding citrus extract to the diet could improve the metabolism level,regulate hormone secretion and improve antioxidant capacity,and alleviate the impact of transportation stress on Yellow feather broiler.
The Biological Function of Selenomethionine and Its Application in Pigs Production
ZHANG Shaotao, LI Min, XIE Yuhuai, CHENG Zhenfeng, YANG Weiren
2020, 47(9):  2824-2832.  doi:10.16431/j.cnki.1671-7236.2020.09.015
Abstract ( 252 )   PDF (1060KB) ( 181 )  
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As an essential nutrient,selenium plays important role in antioxidation,immunity and antitumor.Selenium deficiency in the body can cause diseases such as skeletal muscle degeneration or necrosis,liver necrosis and myocardial fibrosis.Therefore,it has been paid more and more attention in human and animal nutrition.As a kind of organic selenium,selenomethionine (Se-Met) has higher bioavailability and lower toxicity than sodium selenite,and it is an effective organic selenium source to replace inorganic selenium.In response to the current demand for selenium sources in animal production,this article takes Se-Met as the research object,introduces the absorption and metabolism mechanism of Se-Met in the body,and on this basis,makes a comparative analysis with inorganic selenium,highlighting the advantages of Se-Met as an organic selenium supplement.The function and mechanism of Se-Met in the body's antioxidation,immunity and antitumor,and the effect of its application in animal production are briefly described.The application status of Se-Met in pig production is explained,and through the analysis of growth indicators such as daily weight gain,daily feed intake,and feed-to-weight ratio,as well as meat quality indicators such as pH,drip loss,selenium deposition,and meat color of pork,the possibility of Se-Met being widely used in animal production is further determined.This article aims to provide practical reference and theoretical basis for the widespread replacement of inorganic selenium by organic selenium such as Se-Met in animal nutrition in the future,and provide references for subsequent scientific research.
Effects of Dietary Supplementation of β-carotene on Body Fat Color and Vitamin A Content in Tissue of Yak
REN Xiaoying, WANG Shulin, CAO Dexia
2020, 47(9):  2833-2840.  doi:10.16431/j.cnki.1671-7236.2020.09.016
Abstract ( 188 )   PDF (789KB) ( 46 )  
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The purpose of the experiment was to investigate the effect of different levels of β-carotene (β-C) on body fat color and vitamin A content in yaks.In the study,12 yaks aged 2-3 years were randomly divided into 4 groups with 3 replicates.0,720,1 440,1 620 mg/d β-C were added to the basal diet in each group.After 90 days of feeding,the fat,muscle chromaticity,backfat thickness,the contents of β-C and metabolite vitamin A in different tissues of yak were determined.The results showed that,adding different level of β-C in diets,the yellowing (b*) of back,chest fat and hindquarter of yak were significantly higher than that of control group (P<0.05),while brightness (L*) and redness (a*) had no significant change(P>0.05).The backfat thickness of yak reached the maximum value in the middle dose group,and the serum contents of β-C and vitamin A of the control group was significantly lower than each β-C group (P<0.05),and vitamin A content showed an increasing trend with the increase of β-C addition level (P<0.05).The content of β-C in body fat,abdominal fat,heart,liver,spleen,lung,kidney jejunum and other organs of yak reached the maximum value in the middle dose group.Except for the high content of vitamin A in the liver,there was no significant difference of vitamin A content in other tissues among the other treatment groups (P<0.05).In conclusion,dietary supplementation of β-C could affect the color of yak body fat.In the middle dose group,the content of β-C in body fat,heart,liver,spleen,jejunum and other tissues and organs of yak reached the maximum,and the optimum intake was 1 440 mg/d.The addition of β-C in diet had no effect on vitamin A content in yak tissues and organs except liver and serum.
Effects of Addition of Rare Earth-chitosan Chelate to Diets at Different Protein Levels on Sows and Suckling Piglets
XIONG Yi, ZHANG Bo, SHEN Kang, LEI Long, SUN Hua, ZHAO Shengjun, REN Ying
2020, 47(9):  2841-2848.  doi:10.16431/j.cnki.1671-7236.2020.09.017
Abstract ( 202 )   PDF (872KB) ( 118 )  
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The purpose of this experiment was to study the effects of corn-soybean meal diets with different levels of crude protein (CP) adding 200 g/t rare earth-chitosan chelate (RECC) on the reproductive performance of sows and growth performance of their offspring.A total of 60 sows at 90 days of gestation with good physical condition,parity and the expected date of birth were selected.Single-factor randomized block design was used,and sows were divided into 3 groups,20 sows in each group,1 sow each replicate.The level of diet CP and RECC were 17.55% CP,17.00% CP+200 g/t RECC and 16.00% CP+200 g/t RECC in control group,test group Ⅰ and test group Ⅱ,respectively.The test was started from the 90th day of gestation of the sow and ended at the time of weaning at 21 days.The sow litter performance and growth performance of offspring suckling piglets were studied.The final results showed that:Compared with the control group,sow's duration of the test groups Ⅰ and Ⅱ were significantly shortened (P<0.05),but the total litter size and number of born alive did not show significant difference (P>0.05).Postpartum weight loss of sows of the test group Ⅱ was significantly improved (P<0.05),but there was no significant difference in the interval from weaning to estrus (P=0.30).In addition,compared with the control group,sow's ADFI of test group Ⅰ and Ⅱ had an increasing tendency during lactation (P=0.08),and there was no significant difference in ADG,the weight of newborn and weaned piglets (P>0.05),but the diarrhea rate of suckling piglets was significantly reduced (P<0.05).In summary,under the conditions of this trial,when the CP level in the diet was 16.00% and with the addition of 200 g/t RECC,it could improve the reproductive performance of sows,shorten the sow's duration,and reduce the diarrhea rate of suckling piglets.It was of great significance to the improvement of the reproductive performance of sows.
Effects of Clostridium butyricum on Calcium and Phosphorus Metabolism and Tibia Indexes of Broilers
ZHANG Anrong, LIU Jiao, CHEN Zhimin, CHANG Wenhuan, DENG Xuejuan, CAI Huiyi, LIU Guohua, ZHENG Aijuan
2020, 47(9):  2849-2856.  doi:10.16431/j.cnki.1671-7236.2020.09.018
Abstract ( 196 )   PDF (812KB) ( 88 )  
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The effects of Clostridium butyricum on calcium and phosphorus metabolism and tibia indexes in broiler chickens were evaluated in this study.One hundred eighty 1-day-old healthy Arbor Acres broiler chickens were randomly allotted to three groups:the control group,antibiotic group and Clostridium butyricum group with six replicates per group and 10 chickens per replicate.The broilers in control group were fed with the basic diet,while the antibiotic group was fed with 5 mg/kg of flavomycin,75 mg/kg of aureomycin and 20 mg/kg of kitasamycin.Clostridium butyricum group was fed with 2.5×108 CFU/kg Clostridium butyricum in the basic diet for 42 days.The results showed that:Compared with the control group,①the supplementation of Clostridium butyricum did not significantly affect serum calcium and phosphorus level of broilers (P>0.05),and adding antibiotic significantly increased serum calcium level of 21-day-old broilers(P<0.05).②The addition of Clostridium butyricum increased tibia strength at 21-day-old (P<0.05),and phosphorus content of tibia at 42-day-old (P<0.01).③The supplementation of Clostridium butyricum extremely significantly decreased the phosphorus content in feces of 21-day-old broilers (P<0.01),and had no significant difference with ATB group (P>0.05).The supplementation of Clostridium butyricum increased calcium content (P<0.01) and phosphorus content (P<0.05) in feces of 42-day-old broilers.Based on the above results,adding 2.5×108 CFU/kg Clostridium butyricum could improve the tibia development,increase the absorption and utilization of calcium and phosphorus by broilers,and efficiently reduce the calcium and phosphorus excretion of 21-day-old broilers,but not for 42-day-old broilers.
Genetics and Breeding
Effect of Overexpression of FOXL2 Gene on Gonadal Differentiation in Chicken Embryo
XU Wenwen, XIA Li, SUN Tiantian, DENG Jixian, YANG Zhuliang, YANG Xiurong
2020, 47(9):  2857-2865.  doi:10.16431/j.cnki.1671-7236.2020.09.019
Abstract ( 157 )   PDF (8671KB) ( 29 )  
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The aim of this study was to investigate the effect of FOXL2 gene on gonadal differentiation in chicken embryos.This test was divided into the experiment groups 1,2 and blank control group(chicken embryos were 260,100 and 20,respectively).In the experimental group,pLV-FOXL2 lentivirus recombinant plasmids and pLV empty plasmids were injected into the chicken embryo on the second day of the embryonic stage by subpaneoidal injection.The blank control group was not treated and incubated with the experimental groups until the chick was hatched.CHD1 gene genetic sex identification method was used to detect the sex of chicks,the changes of gonadal anatomy and histological structure were analyzed,and the expression levels of FOXL2 and CYP19A1 proteins were detected by immunohistochemistry.The results showed that in the experiment group 1,there were 23 male and 18 female of genetic sex,21 male and 18 female of phenotypic sex,and two of them had atypical phenotypic gender,with changes in the left gonadal gland toward ovarian structure.The phenotypic sex was consistent with the genetic sex in experiment group 2,with 9 male and 12 female.Positive PCR results showed that 10 positive individuals were obtained in the experiment group 1,with a positive rate of 24.4% (10/41),and 8 positive individuals were obtained in the experiment group 2,with a positive rate of 38.1% (8/21).The anatomical structure of the gonad showed that the volume of the left gonad was significantly larger than that of the right gonad in the positive plV-FOXL2 male embryos.The results of tissue sections showed that the gonad of male chicken embryo had typical structure of ovarian cortex and medulla.There was no significant change in the development of gonad in female embryos with positive pLV-FOXL2.Immunohistochemical results showed that the expression levels of FOXL2 and CYP19A1 proteins in the left and right testicle of experiment group 1 were similar to that in the hen ovary of the blank control group,and were significantly higher than that in experiment group 2 (P<0.05).These results suggested that FOXL2 gene might promote the sexual inversion of chicken gonads and played an important role in the differentiation and development of chicken gonads.
Effect of Vitrification on Epigenetics of Mammalian MⅡ Oocytes
HAO Tong, WANG Jingjing, HAO Haisheng, DU Weihua, PANG Yunwei, ZHAO Shanjiang, ZOU Huiying, ZHANG Peipei, ZHU Huabin, ZHAO Xueming
2020, 47(9):  2866-2875.  doi:10.16431/j.cnki.1671-7236.2020.09.020
Abstract ( 177 )   PDF (884KB) ( 82 )  
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As a cell preservation method with simple operation and high success rate,vitrification has many advantages,and it is widely used in agriculture,medicine,biology and other fields.However,compared with fresh oocytes,oocytes after vitrification and freezing still have many problems,such as oocytes after vitrification and freezing have lower pregnancy rate and live birth rate than fresh oocytes,abnormal gene expression and so on.Epigenetic modification allows interaction between genes and the environment without changing the DNA sequence.In the process of in vitro embryo production,external environmental factors will affect the modification of apparent heritage.This article reviewed the effects of vitrification on DNA and whole-genome methylation,histone methylation and acetylation,phosphorylation and ubiquitination,genetic imprinting,and microRNA of mammalian MⅡ oocytes in terms of epigenetics,and the effect of changes in epigenetic modification after vitrified frozen MⅡ oocytes on gene expression during transcription.It provided a reference for revealing and regulating epigenetic modification events after vitrified frozen oocytes,and further improved the quality of vitrified frozen oocytes.
Effects of CART on Estradiol and Related Gene Expression in Buffalo Follicle Granulosa Cells Induced by FSH
LI Lingyu, ZHENG Haiying, YU Nongqi, SHANG Jianghua, Huang Jiaxiang, Yang Chunyan
2020, 47(9):  2876-2883.  doi:10.16431/j.cnki.1671-7236.2020.09.021
Abstract ( 171 )   PDF (4223KB) ( 95 )  
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In this study,primary buffalo ovarian granulosa cells were cultured in a serum-free culture medium in vitro to investigate the effect of exogenous cocaine amphetamine regulated transcript (CART) on the production of estradiol (E2) in granulosa cells induced by follicle stimulating hormone (FSH) and its related gene expression.The granulosa cells was cultured for 7 days by using a long-term method,in each group that was adding different concentration levels of FSH (0,0.25,0.5,1,2 and 4 ng/mL).The concentration of E2 was assayed by ABC-ELISA kit to screen out the optimal dosage of FSH.Primary granulosa cells were randomly divided into 4 group (2 groups of control (without FSH) and 2 groups of optimal FSH levels) for 6 days culure,one of the control group and FSH group were respectively combined with 25 μg/mL CART for 24 h,to detect the change of E2 concentration and quantitative detection the gene expression of CART receptors and aromatase in granulosa cell.The results showed as the follows:①Without CART,the E2 concentration in granulose cells increased first and than decreased with the increased of FSH.When adding 1 ng/mL FSH,the concentration of E2 reached the hightest (116.16 pmol/mL) and significantly higher than the other groups (P<0.05);②Adding CART significantly reduced the concentration of E2 in granulosa cells induced by FSH (P<0.05) and the two control groups 0 FSH and 0 FSH+CARD had no significantly difference (P>0.05).③With 1 ng/mL FSH,exogenous CART significantly reduced the expression of CYP19A1 mRNA in granulosa cells after 24 h treated (P<0.05),while the relative expression of CARTPT mRNA in granulosa cells significantly increased (P<0.05).Under the condition of 0 ng/mL FSH,the expression of CYP19A1 and CARTPT mRNA had no significant difference (P>0.05).Therefore,this study was speculated that CART was a negative regulatory signal in the ovarian development of buffalo,which inhibited the healthy development of follicles,a certain amount of FSH was required to induced the negative pressure of CART on granulosa cell proliferation and differentiation.
Effect of Environmental Estrogen Methomyl on the Quality of in vitro Culture Bovine Oocytes
HE Daohong, HAN Guobo, SUN Jingyu, CUI Yuxin, YIN Ying, ZHANG Xiaomeng, E Zhiqiang, GAO Qingshan
2020, 47(9):  2884-2891.  doi:10.16431/j.cnki.1671-7236.2020.09.022
Abstract ( 178 )   PDF (3091KB) ( 92 )  
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The aim of this study was to evaluate the effects of methotyl (MET) on the quality of in vitro cultured bovine oocytes.The quality of bovine oocytes was evaluated using the first polar body excretion rate,reactive oxygen species (ROS),glutathione (GSH) level,mitochondrial membrane potential (ΔΨm) and the expression of apoptosis-related gene.The results demonstrated that different concentration of MET had no effects on cumulus cells expansion,but the first polar body excretion rate was significantly lower than that of control group after administration of 200 μmol/L MET (P<0.05).The data also showed that 200 μmol/L MET could significantly increase ROS and decrease GSH and mitochondrial membrane potential (P<0.05).In addition,the mRNA transcription levels of Caspase-3 and Bax,which were pro-apoptotic genes,were significantly increased and the anti-apoptotic gene Bcl-xl was significantly reduced after MET administration (P<0.05).The results indicated that MET could increase oxidative stress and apoptosis which led to the reduction of bovine oocytes quality.
Polymorphism of PLIN Gene and Its Associaton with Carcass and Meat Quality Traits in Yanbian Yellow Cattle
ZHANG Luomeng, ZHANG Jiasu, YIN Baozhen, XU Chang, XIA Guangjun
2020, 47(9):  2892-2898.  doi:10.16431/j.cnki.1671-7236.2020.09.023
Abstract ( 228 )   PDF (1293KB) ( 162 )  
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This experiment was conducted to explore the association between perilipin (PLIN) gene and carcass and meat quality traits in Yanbian Yellow cattle.In this study,70 30-month-old healthy Yanbian Yellow cattle were used as experimental materials,the blood of jugular vein and its 12-13 intercostal longissimus muscle dorsi were collected to extract DNA samples of Yanbian Yellow cattle,and determine the carcass and meat quality characteristics.The SNP of PLIN gene was detected by direct sequencing,and the correlation analysis was conducted based on the carcass and meat quality data of Yanbian Yellow cattle and the genetic polymorphism of PLIN gene.The results showed that there were 2 SNPs of PLIN gene exon 3 in Yanbian Yellow cattle:g.103 C→T and g.156 T→C,both of them were missense mutations.g.103 C→T contained two genotypes:CC and CT,CC genotype was the dominant genotype,the genotype frequency was 0.81,C was the dominant allele,the gene frequency was 0.90.The intramuscular fat,pre slaughter weight,carcass weight and back fat thickness of CT genotype was significantly higher than those of CC genotype(P<0.05).g.156 T→C contained two genotypes:TT and TC,TT genotype was the dominant genotype,the genotype frequency was 0.83,T was the dominant allele,the gene frequency was 0.92.The pre slaughter weight,carcass weight and back fat thickness of TC genotype were significantly higher than those of TT genotype (P<0.05).Chi square test showed that the two SNPs of PLIN gene in Yanbian Yellow cattle reached Hardy-Weinberg equilibrium (P>0.05),and belonged to low polymorphism (PIC<0.25).In conclusion,g.103 C→T and g.156 T→C of PLIN gene had potential effect on carcass and meat quality traits in Yanbian Yellow cattle,and could be used as a candidate gene and potential molecular marker of Yanbian Yellow cattle.
Analysis of Related Factors in Semen Quality of Italian Buffaloes
CUI Zhichao, TANG Long, SUN Le, HUANG Shihai, XUE Qingsong, YANG Ting, SHI Deshun, LI Xiangping
2020, 47(9):  2899-2905.  doi:10.16431/j.cnki.1671-7236.2020.09.024
Abstract ( 198 )   PDF (769KB) ( 53 )  
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This study was aimed to investigate the factors affecting semen quality by analyzing the semen quality of Italian buffaloes,measuring the circumference of the testis,the level of oxidative stress in seminal plasma and the expression of genes related to sperm motility.In this study,the sperm vitality,deformity rate and semen collection of 6 Italian buffaloes were tested,and the correlation analysis was carried out after measuring scrotal circumference.The oxidative stress level of seminal plasma in Italian buffaloes was tested,including malondialdehyde (MDA),total superoxide dismutase (T-SOD) and glutathione peroxidation (GSH-Px).The expression of β-tublin-2c (TUBB2C),outer dense fibres 2 (ODF2),tektin-2 (TEKT2),tektin-4 (TEKT4) genes and their correlation with sperm in Italian buffaloes were analyzed.The results showed that the correlation between scrotal circumference and semen yield,vigor and deformity rate was found,the coefficients were 0.423 (P>0.05),0.750 (P<0.01) and -0.827 (P<0.01),which showed a significant positive correlation between scrotal circumference and sperm motility,and a significant negative correlation with the deformity rate.The oxidative stress level in seminal plasma of Italian buffaloes was tested,the correlation coefficients of MDA,T-SOD and GSH-Px with sperm motility were -0.522 (P<0.05),0.333 (P>0.05) and 0.474 (P<0.05),respectively.There was a significant negative correlation between sperm motility and MDA content,a significant positive correlation between GSH-Px activity and sperm motility,no significant correlation with T-SOD activity.The correlation coefficients between sperm motility and TUBB2C,ODF2,TEKT2 and TEKT4 genes were 0.930 (P<0.01),0.726 (P<0.01),0.924(P<0.01) and 0.839 (P<0.01),respectively.There was a significant positive correlation between sperm motility and the expression of four genes.The results provided a reference for understanding the factors affecting the semen quality of Italian buffaloes,and also provided a theoretical basis for the selection of Italian bull.
Effects of Diseases on Reproductive Performance in Dairy Cattle Ⅰ: Current Situation and Its Mechanism
ZHAO Shanjiang, HAO Haisheng, LIU Yunxiang, WANG Xianjun, XU Li, LI Laibao, WANG Huan, ZHU Huabin
2020, 47(9):  2906-2916.  doi:10.16431/j.cnki.1671-7236.2020.09.025
Abstract ( 188 )   PDF (1207KB) ( 156 )  
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Over the past 20 years,with the continuous promotion of the genetic improvement plan of dairy cow population and the continuous improvement of feeding technology,the intensive level and milk yield of dairy cow population in China are continuously improving.However,the reproduction data over the years showed that the more milk yield,the more obviously decline in reproductive performance,and the more prominent of the reproductive problems.The decline of fertility caused by high yield has become the bottleneck of the development of dairy industry in China and even in the world.In dairy farming,there are many factors that cause the reduction of reproductive performance of high-yield dairy cows,including genetic factors,environmental factors and disease factors.Recently,the influence of disease factors on reproductive performance of dairy cows has become more and more prominent.According to the location of the disease,the diseases can be divided into genital diseases and non-genital diseases.This paper discussed the relevant research data on the effects of different diseases on the reproductive performance of dairy cows in recent years,and focusing on the analysis of the molecular mechanism of diseases affecting the reproductive performance of dairy cows through the nervous system,reproductive endocrine system and humoral immune system.The prospect and thinking for the future research of diseases and reproductive performance of high-yield dairy cows were put forward to provide reference and theoretical basis for improving the reproductive efficiency and economic benefits of high-yield dairy cows in China.
Preventive Veterinary Medicine
Epidemiological Cut-off Values (ECOFFs) of Salmonella from Chicken Intestinal Tract for Three Animal-specific Antibiotics
WU Sili, FU Jiali, ZHU Jiahang, ZHANG Yan, DING Xiaomin, JIANG Hongxia
2020, 47(9):  2917-2925.  doi:10.16431/j.cnki.1671-7236.2020.09.026
Abstract ( 183 )   PDF (1493KB) ( 110 )  
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In order to establish epidemiological cut-off values (ECOFFs) of Salmonella for three animal-specific antibiotics (florfenicol,apramycin and danofloxacin) in Guangdong province.A total of 166 strains of Salmonella isolates from chicken intestinal tract from veterinary clinics and farms in Guangdong province in 2017 were recruited in this study,the minimum inhibitory concentrations (MIC) of florfenicol,apramycin and danofloxacin were determined in triplicate for each bacterial strain using the agar dilution method on Mueller-Hinton agar plates according to the CLSI reference method (CLSI-M100-S26).ECOFFs were calculated for the MIC data sets by application of nonlinear regression analysis,NRI(normalized resistance interpretation) and ECOFFinder software.MIC distribution of florfenicol,apramycin and danofloxacin against Salmonella from 2 to >512,4 to >512 and 0.015 to 64 μg/mL,respectively.MIC50 and MIC90 for apramycin,florfenicol and danofloxacin were 256 and >512,16 and >512,0.5 and 16 μg/mL,respectively.MIC distribution of apramycin and florfenicol presented obvious unimodal shape,while that of danofloxacin was a discontinuous multi-peak.The ECOFFs of florfenicol,apramycin and danofloxacin were recommended to be 16,16 and 0.125 μg/mL,respectively.In present study,the ECOFFs of Salmonella from chicken intestinal tract for apramycin,florfenicol and danofloxacin were determined,which provided scientific basis for resistance surveillance.
Molecular Epidemiology of Bovine Astrovirus in Buffalo from Guangxi
LI Mingyang, FANG Qingli, HUANG Weijian
2020, 47(9):  2926-2934.  doi:10.16431/j.cnki.1671-7236.2020.09.027
Abstract ( 192 )   PDF (1696KB) ( 142 )  
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This study was aimed to investigate the prevalence of bovine astrovirus (BoAstV) in buffalo from Guangxi,a total of 297 fecal samples were collected from 15 different scale buffalo farms in five regions including Nanning,Guigang,Beihai,Hengxian and Lingshan in Guangxi,the RNA was extracted by Trizol and the nest RT-PCR was used to detect the BoAstV.The positive samples were connected to pMD18-T vector for sequencing.Homology analysis of sequencing results was carried out,and phylogenetic tree was constructed.The results showed that the positive rate of BoAstV in buffalo farms was 40.00% (6/15),the positive rate of samples was 11.11% (33/297), and the buffalo calves which under 180 days old were more sensitve to infected BoAstV 18.75% (27/144).Total 19 BoAstV ORF1b sequences from positive samples were cloned and uploaded to NCBI BLAST.The nucleotide homology and amino acid sequence homology of the 19 BoAstV strains were 53.9% to 99.3% and 12.1% to 98.5%,respectively.Based on the phylogenetic analysis of these sequences and reference sequences,4 clusters could be classified.The first subgroup included NNC-286,HX-3,HX-4 and NNA-14,and these sequences were closed with novel nervous tropism BoAstV like BoAstV NeuroS1 and BoAstV BH89/14 which belonged with Mamastrovirus 13.The second subgroup included NNA-12,NNA-13,NNA-17 and NNA-11,and these sequences were closed with buffalo astrovirus,and belonged to the branch of buffalo astrovirus.The third subgroup included HX-1,HX-5,HX-6 and BH-C22,and these sequences were closed with classic BoAstV like BoAstV B170-HK.The last subgroup included NNA-7,NNA-15,NNA-6,NND-S2,NND-S16,NNC-296 and BH-C14,and these sequences were closely related to the local endemic strains of bovine stellavirus in Guangxi.The different genotype of BoAstV were infected buffalo herds in different regions from Guangxi.This study found that the neurophilic BoAstV strain infected buffalo in Guangxi,and provided reference for further understanding of the epidemiology and biological characteristics of the virus.
Research Advances on Porcine Epidemic Diarrhea and New Vaccine
GUO Sijie, LIU Junqi, LI Yujuan, SUN Zhiliang
2020, 47(9):  2935-2944.  doi:10.16431/j.cnki.1671-7236.2020.09.028
Abstract ( 379 )   PDF (1059KB) ( 193 )  
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Porcine epidemic diarrhea (PED) is one of the important diseases that endanger the healthy development of the pig industry.It has acute and highly infectious characteristics,causing severe economic losses to the pig industry.Porcine epidemic diarrhea virus (PEDV) infection could destroy the animal's digestive system,cause the appetite of sick pigs to decline,vomit,and severe diarrhea.And the piglets cured by drugs will also have a serious impact on production due to factors such as poor growth and development,which will bring huge problems to the farmers.The outbreak of PEDV highly pathogenic mutant strains in China in 2010 led to a significant increase in the incidence and mortality of PED,which severely affected pig production in China.The outbreak of PED has drawn close attention from the pig industry.Scholars in related research fields have conducted more in-depth research on the pathogenic mechanism of PEDV and the new PED vaccine.Five new types of PED vaccines,including subunit vaccine,virus live vector vaccine,bacterial live vector vaccine,transgenic plant vaccine and nucleic acid vaccine,have been developed successively,and new breakthroughs and progress have been made.Compared with the traditional PED inactivated vaccine and PED attenuated vaccine,the new PED genetically engineered vaccine has the advantages of good safety,simple preparation,and good immune effect.This article focuses on the pathogenesis of PEDV and the research progress of five new PED vaccines,so as to deepen our understanding of new PEDV and PED vaccines,in order to provide references for prevention and control measures of PEDV infection.
Isolation,Identification and Immunogenicity Evaluation of H9N2 Subtype Avian Influenza Virus HF Strain
CHENG Yi, TIAN Hui, ZHANG Ya, XUE Jingjing, SHENG Dongbei, LIU Wujie, WANG Wanbing, ZHANG Pantao, TIAN Kegong
2020, 47(9):  2945-2952.  doi:10.16431/j.cnki.1671-7236.2020.09.029
Abstract ( 176 )   PDF (1367KB) ( 75 )  
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In 2015,an H9N2 subtype avian influenza virus (AIV) strain was isolated from a chicken farm in Hefei,Anhui,and named HF strain.The results of the chicken embryo proliferation characteristics study showed that the half infection rate of chicken embryo (EID50) was 109.17/0.1 mL,and the mean time to death for minimum lethal dose(MDT) was 87 h.The analysis result of HA gene showed that its amino acid cleavage site was located in RSSR↓GLF,which accorded with the characteristics of low pathogenic avian influenza.The genetic evolution analysis of HA gene revealed that the isolate belonged to the h9.4.2.5 lineage,which accorded with the current virus strain epidemic characteristics.The HF strain was prepared with 10 H9N2 subtype AIV isolates which isolated from all over the country from 2006 to 2018 to prepare inactivated vaccines,immunize SPF chickens,prepare positive sera,and analyze the virus antigenicity by cross hemagglutination inhibition test.The results showed that the correlation between the HF strain and the virus antigens before 2014 and was between 0.50-0.56,and the virus antigen correlation after 2014 was 0.89-1.00.This showed that the isolate had good antigenic correlation with epidemic strains in recent years.Inactivate HF strain virus solution with 0.2% formaldehydel,and its HA titer did not change before and after inactivation.After the inactivated virus solution was prepared into an oil emulsion inactivated vaccine to immunize SPF chickens,21 days after immunization,the average value of the HI antibody titer reached 9.0log2.It could make immune chicken completely resistant to H9 subtype AIV infection and provide 100% protection from challenge.The above research results showed that the HF strain had good immunogenicity and could be used as a vaccine candidate strain for the prevention of H9N2 subtype AIV.
Prokaryotic Expression and Polyclonal Antibody Preparation of σC Protein of Novel Duck Reovirus DH13 Strain
LI Wenjun, HUANG Huilan, YANG Huihu, XIE Zimin, CUI Huiyi, HUANG Shujian, ZHANG Xuelian
2020, 47(9):  2953-2959.  doi:10.16431/j.cnki.1671-7236.2020.09.030
Abstract ( 228 )   PDF (2756KB) ( 127 )  
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The aims of the experiment was to optimize the prokaryotic expression system of σC protein,prepare polyclonal antibody against σC protein of novel duck reovirus (NDRV),and evaluate the titer of the antibody.The σC gene of NDRV-DH13 strain was amplified by RT-PCR,ligated into pET-30a(+) and pET-32a(+) expression vector,constructed prokaryotic expression plasmid,which were transformed into E.coli BL21(DE3) and the expression of the σC protein were induced by IPTG.The proteins expression were analyzed by SDS-PAGE.The recombinant protein without His tag was purified by digestion,and the recombinant protein with His-tagged was purified by Ni-NTA column.Then the polyclonal antibody was obtained from rabbits which had been immunized by the purified protein without His tag.Anti-His-labeled mAb and NDRV-σC positive serum were used as primary antibodies to evaluate antibodies specificity,the antibodies titer was detected by indirect ELISA (iELISA).SDS-PAGE results showed that the molecular weight of the expression on recombinant proteins were 34 and 37 ku respectively,the proteins were highly expression.Western blotting showed that they had the specific reaction and the prepared antibodies had higher affinity with σC protein,the titer were about 1:25 600 by iELISA detection.This study successfully constructed and optimized the prokaryotic expression system of the polyclonal antibody against σC protein,laid a foundation for the further study of σC protein and the research of genetically engineered vaccine.
Relationship Between Expression Levels of Porcine m6A Demethylases FTO and ALKBH5 Genes and Resistance to E.coli F18 Infection
QI Xiaoyi, YANG Li, WU Zhengchang, BAO Wenbin, WU Shenglong
2020, 47(9):  2960-2967.  doi:10.16431/j.cnki.1671-7236.2020.09.031
Abstract ( 177 )   PDF (1224KB) ( 91 )  
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To investigate the relationship between the mRNA expression level of m6A demethylase and E.coli F18 resistance in piglets,Real-time quantitative PCR was used to detect the mRNA expression differences of m6A demethylase FTO and ALKBH5 genes in the duodenum and jejunum tissues of E.coli F18-resistant and -sensitive individuals from 35-day Sutai weaned piglets.In E.coli F18ab,F18ac bacteria-stimulated and endotoxin LPS-induced porcine small intestinal epithelial cells (IPEC-J2),the expression levels of FTO and ALKBH5 genes were detected,respectively.The results showed that the expression levels of FTO and ALKBH5 genes in the duodenum and jejunum of resistant individuals were extremely significantly or significantly higher than those of sensitive individuals (P<0.01,P<0.05),and the expression of FTO gene were not significantly changed in E.coli F18 bacteria-stimulated IPEC-J2 cells (P>0.05),but the expression levels of ALKBH5 gene were significantly up-regulated after F18ac stimulation (P<0.05).After LPS induction for 4 hours,the expression levels of FTO and ALKBH5 genes showed significant up-regulation in IPEC-J2 cells (P<0.05).This study preliminarily verified and indicated that the expression levels of m6A demethylases FTO and ALKBH5 genes were closely related to E.coli resistance of piglets at the cellular and individual levels,which will provide a theoretical basis for future in-depth study of the regulation mechanism of RNA demethylation modification on bacterial diarrhea in piglets.
Basic Veterinary Medicine
Study on the Anti-Escherichia coli Activity and Mechanism of Water Extract of Radix isatidis Powder
JIANG Xiaowen, YAN Ge, LI Shuhong, YU Wenhui, WEI Jiayu, AI Liwen, BAI Wen
2020, 47(9):  2968-2978.  doi:10.16431/j.cnki.1671-7236.2020.09.032
Abstract ( 162 )   PDF (5864KB) ( 122 )  
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In order to explore the antibacterial activity and mechanism of the Radix isatidis powder water extract,the effects of the Radix isatidis powder water extract on the morphology and structure of Escherichia coli (E.coli) were tested by scanning electron microscopy and transmission electron microscopy.The effects of the Radix isatidis powder water extract on the conductivity and total leakage rate of E.coli and the content of alkaline phosphatase in the culture medium of the content of protein,DNA and RNA were stained by DAPI to detect the effect of the Radix isatidis powder water extract on the nucleic acid of E.coli,and the effect of the Radix isatidis powder water extract on the metabolism of E.coli in vivo,in vitro,ALT,AST,pyruvic acid and ATP.The results showed that after the Radix isatidis powder water extract acted on E.coli for 10 h,it was observed by SEM that the bacteria appeared to overflow and shrink,the length of the bacteria became shorter obviously,many residues were formed due to breakage,some of them were sunken in the middle and deformed.Under TEM,it was observed that the boundary of the cell wall of E.coli was unclear,the wall membrane was zigzag,deformed and some of the bacteria were broken.The protein content outside the cell was significantly different from that in the blank control group from 8 h (P<0.01), and that in the cell from 4 h (P<0.01). DNA content had no significant difference with blank control group before 12 h (P>0.05), but had significant difference with blank control group from 16 h (P<0.01); RNA content began to decrease at 8 h, and was significantly different from blank control group at 12 h (P<0.05), and was extremely significant from 16 h (P<0.01). There was no significant difference between ALT and AST (P>0.05). The pyruvate content in culture medium and bacteria was higher than that in blank control group, and the difference was very significant from 4 h (P<0.01). The ATP content in the culture medium was significantly different from that in the blank control group (P<0.01), and the ATP content in the cell was significantly different from that in the blank control group from 4 h (P<0.01).In conclusion,the Radix isatidis powder water extract could inhibit the synthesis and metabolism of bacterial genetic material and the content of pyruvate and ATP by destroying the integrity of cell wall and cell membrane.
Comparison of Drug Resistance and Virulence Genes of Three Strains of Aeromonas veronii
ZHANG Piao, HU Andong, YANG Xia, PAN Jimai, LIU Yanhan, ZENG Maoqin, CHENG Zhentao, JIANG Haibo, WEN Ming
2020, 47(9):  2979-2987.  doi:10.16431/j.cnki.1671-7236.2020.09.033
Abstract ( 187 )   PDF (2743KB) ( 129 )  
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To find out whether there were differences in drug resistance and virulence genes of Aeromonas veronii (A.veronii) from different regions,this study compared morphology,biochemistry test,drug sensitive test,artificial infection test,16S rDNA gene sequencing and virulence genes homology analysis for grass carp source strain GZCY2019,hybrid sturgeon source strain GZXY2018 and Ictalurus punctatus source strain GZBD2017.The results showed that all the three strains of A.veronii from different sources presented round,moist and smooth gray and translucent colonies with neat edges on the blood plate,and the colonies were surrounded by β hemolytic rings.Gram staining showed that negative Bacillus crassus at both ends.Drug sensitivity test showed that the three strains were all sensitive to butylaminacana,doxycycline,but were all intermediary to compound xinnomin,ceftadime,polymyxin B and other drugs,while were at different degrees of sensitivity or resistance to other drugs.Artificial infection test showed that the cumulative death rates of GZCY2019 and GZBD2017 were both 100%,while the rate of GZXY2018 was 80%.The homology analysis of 16S rDNA showed that the homology between GZCY2019 and GZBD2017 was 99.9%,while the homology between the former two strains and GZXY2018 was 97.1%.Virulence gene test results showed that Alt,hlyA and Fla virulence genes were all carried,while cytotoxic enterotoxin Act and Ast virulence genes were different.In this study,through comparison of multiple experiments with different sources of A.veronii,it was found that the three strains were basically similar in growth morphology,staining microscopy and biochemical results,but there were significant differences in resistance and virulence genes.
Experimental Infection of Mycoplasma ovipneumoniae in SPF Chicken Embryos
YUAN Ting, HAO Huafang, MA Lina, CHEN Shengli, YAN Xinmin, WU Yaqin, CAI Yating, SUN Yanming, CHU Yuefeng
2020, 47(9):  2988-2996.  doi:10.16431/j.cnki.1671-7236.2020.09.034
Abstract ( 198 )   PDF (3496KB) ( 81 )  
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In order to evaluate the SPF chicken embryos as a candidate of the experimental model of Mycoplasma ovipneumoniae (Mo) infection,the 7-day-old SPF chicken embryos were infected with different concentrations of Mo(108,109 and 1010 ccu/mL) by injection of vitelline fluid and allantoic cavity.The mortality and Mo detection rate (PCR detection and isolation) of infected chicken embryos were employed to evaluate the optimal inoculation route,dose and sampling site.Three different isolates of Mo were submitted to injection of chicken embryos for pathogenicity comparison.The results showed that the optimal inoculation route and dose were vitelline fluid injection with 0.2 mL (109 ccu/mL) Mo per embryo and the sampling site for detection was also vitelline fluid.Three Mo isolates revealed good infectivity and lethality to the chicken embryo.The chicken embryos mortality caused by FL3 strain (45%) and MoGH3-3 (40%) were both higher than that by A3 strain (25%),but with no significance (P>0.05).The detection rate of Mo from the chicken embryos in FL3 group (100%) was higher than that of MoGH3-3 strain(85%) and that of A3 strain (90%),but with no significance(P>0.05).This experiment preliminarily proved that the SPF chicken embryos could be infected and partially killed by Mo,and the virulence of different strains of Mo to the chicken embryos was different.The results provided the data for further establishment of the chicken embryo infection model of Mo,which would benefit the research on Mo pathogenicity and vaccine development.
Isolation and Identification of Enterococcus faecalis from Fur-bearing Animals
CI Yang, SHI Xiaojie, SONG Peng, DING Qi, LI Wenli
2020, 47(9):  2997-3005.  doi:10.16431/j.cnki.1671-7236.2020.09.035
Abstract ( 197 )   PDF (2286KB) ( 82 )  
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In order to obtain Enterococcus faecalis from fur animals and evaluate its prebiotic properties,in this study,Enterococcus faecalis was isolated from the feces of healthy adult fur-bearing animals (mink,fox,raccoon dog),identified by morphological observation,biochemical test and 16S rRNA sequence analysis.The growth curve,acid production capacity and antibiotic sensitivity of the Enterococcus faecalis isolates were measured to evaluate their probiotic properties.Some strains were selected to determine their tolerance to temperature,artificial gastric juice and artificial bile salt.The results showed that five strains were Gram-positive,and their biochemical characteristics were basically consistent with the standard strains of Enterococcus faecalis,and they were identified as Enterococcus faecalis by 16S rRNA sequence analysis.The five strains all entered the logarithmic phase at 2 h after culture,and entered the stable phase at 8-10 h,and had weak acid production capacity.The resistance rate of the isolates to tetracycline and levofloxacin was 100%,followed by penicillin (80%),erythromycin (80%),gentamicin (80%) and chloramphenicol (40%).All the isolates were sensitive to ampicillin and vancomycin.Enterococcus faecalis from mink,fox and raccoon dog had strong tolerance to temperature below 60 ℃,artificial gastric juice with pH>3.0 and 0.3%-0.5% concentration of bile salt,but poor tolerance to temperature above 70 ℃,and artificial gastric juice with pH<3.0.In conclusion,five strains of Enterococcus faecalis from fur animals (mink,fox,raccoon dog) were obtained in this study.The isolated strains propagated rapidly,which were suitable for colonization and played a prebiotic role in fur animals' intestines,and had good prebiotic characteristics and stress resistance.They could be used as candidate strains for animal microbiological agents for further study.
Design and Activity Identification of Hybrid Peptide Based on Cecropin A and Mastoparan
ZHAI Pei, HAN Jinhui, PAN Xiaoyu
2020, 47(9):  3006-3013.  doi:10.16431/j.cnki.1671-7236.2020.09.036
Abstract ( 204 )   PDF (2245KB) ( 87 )  
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In order to further improve mastoparan's antibacterial and antitumor activities and reduce its cytotoxicity,the molecular modification was carried out by molecular hybridization,and the biological activity of the designed peptide was identified.A novel hybrid peptide KL-21 was obtained by using the N-terminal 1-8 sequences fragment of cecropin A and the conserved sequence of mastoparan.The physicochemical parameters and structures of KL-21 were analyzed by bioinformatics method.The antibacterial activity of KL-21 was studied with MP-L as reference.In addition,the hemolysis rate of the two peptides and the activity of anti-tumor cell A549 were measured.The results showed that KL-21 could quickly kill bacteria in a shorter time.The minimum inhibitory concentration (MIC) of KL-21 to Gram-positive bacteria (S.aureus) and Gram-negative bacteria (E.coli) was 4-8 μg/mL,and the minimum bactericidal concentration (MBC) was 8-16 μg/mL.The MIC and MBC of KL-21 to fungus (C.albicans) were 32 and 64 μg/mL,respectively.The hemolytic activity of KL-21 was only 20% at 128 μg/mL,which was lower than that of MP-L.KL-21 could inhibit lung cancer cell A549 with inhibition rate in vitro about 86% at 16 μg/mL.These results indicated that KL-21 had higher antibacterial and antitumor activity and lower cytotoxicity than MP-L,which could be used as a leading peptide for further research and development.
Isolation,Identification and Biological Characteristics of Staphylococcus chromogenes from Tibetan Pigs
ZHAO Xialing, XIAO Qi, QIAN Wenxian, WEN Dongxu, YAN Mingshuai, LYU Lixin, NIU Jiaqiang, HE Kongwang
2020, 47(9):  3014-3021.  doi:10.16431/j.cnki.1671-7236.2020.09.037
Abstract ( 206 )   PDF (4852KB) ( 97 )  
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In order to understand the infection of Staphylococcus disease in healthy Tibetan pigs in Linzhi city,Tibet.232 samples were collected from the slaughterhouse in Bahe town,Gongbujiangda county,Linzhi city,Tibet,the teaching practice ranch at the Tibet Agriculture and Animal Husbandry University in Bayi district,Linzhi city,and the slaughterhouse in Bayi district,Linzhi city.These samples were isolated,cultured and identified,and one isolated strain was systematically studied for biological characteristics.Epidemiological survey results showed that 73 of 232 samples were positive for Staphylococcus,the positive rate was 31.47%,16 positive samples were detected in the slaughterhouse of Bahe town,Gongbujiangda county,Linzhi,Tibet,with a detection rate of 23.89%(16/67),43 positive samples were detected in the pastures of the teaching practice ranch at the Tibet Agriculture and Animal Husbandry University in Bayi district,Linzhi city,with a detection rate of 34.40% (43/125),14 positive samples were detected in the slanghterhouse in Bayi district,Linzhi city,with a detection rate of 35.00% (14/40).Through PCR identification,gene sequencing and biochemical identification,5 strains of Staphylococcus chromogenes were isolated,and one of them (Sa LZ1) was studied systematically.The biological characteristics of the isolated strains showed that the Sa LZ1 strain formed round white convex colonies on the agar medium,with regular edges,smooth surfaces,and opaque white colonies.The isolates were Gram-positive cocci bacteria.PCR sequencing results showed that the isolate had the highest homology with Staphylococcus chromogenes (GenBank accession No.:MG576253.1),positive for serum inulin,manicol,glucose,saccharose,lactose,negative for arabinose,sodium hippurate,raffinose,xylose,urea,etc,consistent with the biochemical characteristics of Staphylococcus chromogenes.The logarithmic growth period of isolated bacteria was 5 to 10 h.The pathogenicity test of mice showed that the mortality rate of mice reached 100% when the concentration of Sa LZ1 strain reached 3.5×109 CFU/mL.And the results of pathological section showed that Sa LZ1 strain could cause the visceral tissue of mice to develop pathological changes.The above results provided a theoretical basis for the prevention and control of Staphylococcus suis in Linzhi,Tibet.
Advance on the Tigecycline Resistance Mechanism
WANG Liangliang, WANG Qianqian, ZHOU Bolun, JIA Yixin, WU Hua, YUAN Li, HU Gongzheng, HE Dandan
2020, 47(9):  3022-3029.  doi:10.16431/j.cnki.1671-7236.2020.09.038
Abstract ( 400 )   PDF (1047KB) ( 150 )  
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Tigecycline,as a new tetracycline antibiotic,is one of the last lines of defense against carbapenems-producing enterobacter multidrug-resistant infections.In recent years,the emergence of tigecycline-resistant strains has severely restricted the clinical use of tigecycline.It was originally believed that the resistance mechanism of tigecycline was mediated by the efflux pump encoded by the chromosome,which could not lead to drug resistance by horizontal transfer.With the deepening of research,it was found that some efflux pump mutations or high expression on the plasmid could also cause the strain's tigecycline sensitivity to decrease.Recently,it has been reported that the plasmid-mediated tet(X) variant can make the strain highly resistant to tigecycline,and can be spread among different species of bacteria through adaptable plasmids.This article described the prevalence and transmission mechanism of high-level tigecycline resistance gene tet(X) variants by introducing bacterial chromosome-mediated tigecycline resistance mechanisms and plasmid-mediated tigecycline resistance mechanisms,and provided a reasonable explanation for the high-level variant of the tigecycline resistance gene tet(X) in animal-derived strains,aiming to provide reference for relevant scientific researchers and clinical workers.
Study on the Intervention Effect and Mechanism on Insulin Resistant Mice of Total Flavone from Melastoma dodecandrum Lour.
ZHOU Jingkai, HUANG Xinhui, LIU Shulin, WENG Jingyu, ZHU Pan, LI Li
2020, 47(9):  3030-3037.  doi:10.16431/j.cnki.1671-7236.2020.09.039
Abstract ( 193 )   PDF (16305KB) ( 40 )  
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This experiment was conducted to explore the intervention effect and mechanism on insulin resistance (IR) mice of total flavonoids from Melastoma dodecandrum Lour.(TFMD).The model of IR mice was established by intragastric administration of high-fat emulsion,while 600,300 and 150 mg/kg TFMD were administered once daily for 30 days.After the end of the experiment the mices' fasting blood glucose (FBG),fasting serum insulin (FINS),serum total cholesterol(TC),triglyceride (TG),high density lipoprotein(HDL) were determined.The mRNA expression level of liver insulin receptor(InsR),fat peroxisome proliferator-activated receptor-γ(PPAR-γ),and glucose transporter 4 gene (GLUT4) in skeletal muscle were detected by Real-time quantative PCR,and the protein levels were detected by immunohistoche mical method.The results showed that TDMF could reduce the body weight of IR mice,decrease the level of serum FBG,FINS and HOMA-IR,increase the level of ISI,decrease the content of serum TG,TC and LDL,and increase the content of HDL(P<0.01,P<0.05);And the mRNA expression of INSR,PPAR-γ in liver and GLUT4 in skeletal muscle of IR mice were increased(P<0.01,P<0.05),and the protein expression level of InsR,PPAR-γ in liver and GLUT4 in skeletal muscle of IR mice were increased(P<0.01,P<0.05).The results confirmed that the TFMD could relieve experimental insulin resistance in mice,and the activity was related to the regulation of glucose and lipid metabolism and the enhancement of insulin sensitivity.