关键词: 鸡传染性支气管炎; 四黄散; 治疗效果; 肠道菌群

Abstract: 【Objective】 The aim of the experiment was to study the therapeutic effect of Sihuangsan on infectious bronchitis (IB) and its effect on intestinal flora.【Method】 A total of 100 10-day-old SPF chicks were randomly divided into 5 groups:Control group,virus group and Sihuangsan low,medium and high dose groups,with 20 chicks in each group.Except for control group,the chicks in the other groups were inoculated with 10^-4.67/100 μL of IBV-QX virus solution (0.25 mL per chick) by nasal drop and eye spot.24 h after the challenge,chicks in Sihuangsan low-,medium- and high-dose groups were given 2,4,and 6 mL Sihuangsan liquid with a concentration of 1 g/mL,respectively,by drinking water,and administered twice a day in the morning and evening,and chicks in control and the virus groups drank ultrapure water,clinical symptoms were observed daily.After 24 days of continuous administration,all chicks were autopsied,trachea,lung and kidney samples were collected,the pathological changes were analyzed,and the contents of the chicken cecum were aseptically collected to measure the structure and diversity intestinal flora.【Result】 On the third day of administration, the chicks in virus group showed symptoms such as loss of appetite, dyspnea and diarrhea.On the 7th day of administration,the clinical symptoms of chicks in each dose group of Sihuangsan gradually decreased,and on the 8th day of administration,the symptoms of dyspnea of chicks in the medium- and high-dose groups disappeared and their appetite was restored.The results of histopathological observation showed that,compared with virus group,chicks in Sihuangsan groups did not have large-scale exfoliation of the respiratory epithelium of the tracheal mucosal layer,alveolar collapse and inflammatory cell infiltration of the alveolar wall,and no pathological changes such as glomerular endothelial cell proliferation,inflammatory exudation and necrosis were found.The tracheal mucosal layer of chicks in Sihuangsan medium-dose group was intact,ciliated cells and goblet cells were visible,alveolar structure was intact,glomerular structure was intact,and inflammatory cells were occasionally aggregated.The results of cecal microbiota changes showed that compared with control group,the Shannon index of the virus group was significantly decreased,and the Simpson index was significantly increased (P＜0.05). Compare with virus group,the Shannon index of Sihuangsan groups was significantly increased,and the Simpson index was significantly decreased (P＜0.05).The results of Beta diversity analysis of cecal microbiota showed that the composition of the microflora between Sihuansan groups and control group was highly similar,and there was no obvious difference.The microbial communities between virus group and Sihuangsan and control groups were significantly separated,and the differences were obvious.At the phylum level,the relative abundance of Proteobacteria in virus group was higher than that in control group and Sihuangsan groups,and the relative abundance of Firmicutes was lower than that in control group and Sihuangsan groups.At the genus level,the relative abundance of Lactobacillus in virus group was significantly lower than that in control group,and Lactococcus and Inconstantimicrobium in Sihuangsan medium dose group were significantly higher than those in virus group.【Conclusion】 Sihuangsan could effectively change the clinical symptoms,pathological changes,cecal microbiota structure and diversity of infectious bronchitis chickens,and the middle dose (0.4 g per chick) group had the best effect.

Key words: infectious bronchitis; Sihuangsan; therapeutic effect; intestinal flora