China Animal Husbandry and Veterinary Medicine ›› 2021, Vol. 48 ›› Issue (5): 1535-1543.doi: 10.16431/j.cnki.1671-7236.2021.05.004

• Biotechnology • Previous Articles     Next Articles

Analysis of Multilocus Sequence Typing and Genetic Evolution of Streptococcus uberis

FU Shaodong1, QIU Yawei1, WEN Chen1, ZHANG Yihao1, CHEN Wei2, LUO Zhenhua3, ZHANG Jinqiu4, MIAO Jinfeng1   

  1. 1. College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China;
    2. Engineering Laboratory of Tarim Animal Diseases Diagnosis and Control, Xinjiang Production & Construction Crops, College of Animal Science, Tarim University, Tarim 843300, China;
    3. School of Water, Energy & Environment, Cranfield University, Bedfordshire MK430AL, United Kingdom;
    4. Institute of Veterinary Immunology & Engineering, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
  • Received:2020-09-03 Online:2021-05-20 Published:2021-05-20

Abstract: The purpose of this study was to explore the diversity and genetic evolution of Streptococcus uberis (S.uberis) from different regions in China.In this study,38 strains of S.uberis isolated from some regions of China were used as the research objects.Through the determination of their minimum inhibitory concentration (MIC) and the sequencing of the whole genome frame,the related information of drug resistance,drug resistance gene and virulence gene of 38 strains were obtained.The alleles,sequence type (ST) and clone complexes (CCs) of 7 housekeeping genes were analyzed by multilocus sequence typing technique (MLST),and their evolutionary tree was established.A total of 15 antibiotics were used in MIC test,it was found that 38 strains of S.uberis were resistant to 13 antibiotics except for cefotaxime and florfenicol,and the drug resistance in Jiangsu province was significantly stronger than that in Xinjiang province.After comparison of resistance and virulence genes,only 24 strains were found to carry drug resistance genes,and the remaining 14 strains did not carry drug resistance genes and belonged to Xinjiang isolates,which was consistent with the results of MIC test.Among the 15 virulence genes,except for cfu,hasA/B and lbp,the carrying rate of the remaining 12 virulence genes was as high as 100%.Based on the MLST's results,38 strains of S.uberis belonged to 17 ST types,of which 15 ST types were not reported,and only 1 strain of supan01 belonged to ST-5 CCs.The phylogenetic tree results showed that the 38 isolates largely unrelated,and their distribution was region-dependent.Moreover,the phylogenetic tree results suggested that the S.uberis strains prevalent in some parts of China were largely different from those prevalent in Western countries.This study contributed to the MLST database of S.uberis and provided a reference basis for understanding of the genetic and distribution characteristics of S.uberis in China.

Key words: Streptococcus uberis; multilocus sequence typing (MLST); housekeeping gene

CLC Number: