Investigation Of Infection And Virulence And Drug Resistance Detection In Layer Farm Gallibacterium Anatis In Some Areas Of Southern Xinjiang

Gallibacterium anatis（Gallibacterium anatis,G.anatis）is a common bacterium that colonizes the respiratory tract and reproductive tract of poultry.It can cause peritonitis and fallopian tube lesions of poultry,decrease egg production and increase mortality of laying hens,and easily cause secondary infection and mixed infection,which brings great losses to the poultry industry around the world.In addition,the bacteria can infect a variety of hosts,not only birds,but also some mammals including humans,such as cattle,sheep,pigs,etc.,which not only endangers the development of the poultry industry,but also poses a potential threat to the health of humans and other animals.In order to understand the prevalence of G.anatis infection in Aksu,Hotan and Kashgar of Xinjiang,cotton swabs of upper cleft palate and cloaca cotton swabs were collected from some hens in 9 counties of these 3 districts,and bacteria were isolated and identified.Morphological observation,biochemical and molecular biological identification,drug sensitivity test,animal regression test were conducted for isolated strains,and virulence and drug resistance genes were detected.To understand the biological characteristics and infection of G.anatis in southern Xinjiang,and to provide reference for prevention and control of duck-derived chickenobacilllosis and rational drug use.In this study,412 cotton swabs of roof cleft palate and cloacal cotton swabs were collected from laying hens in Wensu County,Shaya County,Awati County,Hetian County,Pishan County,Moyu County,Shufu County,Shule County and Shache County in southern Xinjiang,and the pathogenic bacteria in these swabs were isolated and identified.The results showed that 63 strains of G.anatis were isolated from the swabs of upper cleft palate and cloaca.The positive rate of Aksu was the highest(22.00%（33/150）;the positive rate of Hetian was the lowest(9.59%（14/146）;the positive rate of Kashi was 13.79%（16/116）.The drug sensitivity tests of 24 kinds of antibiotics were performed on 63 strains of G.anatis.The results showed that the resistance rates of 63 isolates to P,SXT,TET,STR,CLI,NOR,ERY and MID were the highest,all over 80%.AMP,DOX,NEO,CIP,and POL were the next,and the drug resistance rate was60%～80%.Completely sensitive to TGC display;The drug resistance of the remaining 10 antibacterial drugs was less than 30%.The results of drug resistance gene detection showed that 11 genes were detected from 25 kinds of drug resistance genes,bla _TEM,sul2,aac（6’）-Ib,gyr A,aad B,aph（3’）-Ia,Str A,aac（6’）/aph（2"）,aph A,TEM,tet（B）.The detection rates were 30.15%（19/63）,20.63%（13/63）,33.33%（21/63）,28.57%（18/63）,23.81%（15/63）,20.63%（13/63）,30.16%（19/63）,33.33%（21/63）,42.86%（27/63）,50.79%（32/63）,34.92%（22/63）.The results of 27 virulence genes showed that a total of 11 virulence genes were detected,The detection rates were Gtx A（88.89%）,flf A（49.20%）,ECs3703（42.86%）,cnf2（34.92%）,fim H（28.57%）,tol C（25.40%）and omp F（22.22）,omp W（22.22%）,omp C（17.46%）,omp A（14.29%）,Irp2（11.11%）,indicating that most G.anatis isolates in southern Xinjiang carried multiple virulence genes.The isolates carrying the 11 virulence genes were inoculated into chicks and mice.The results showed that G.anatis could cause the chicks and mice to die within 12 h to 24 h.Necropsis of dead chicks showed bleeding of liver,spleen,glandular stomach,muscular stomach and intestinal mucosa,ureteral urate deposition and other pathological changes.Necropsy of the dead mice showed liver and spleen enlargement,bleeding,tubal and uterine congestion and other pathological changes.The results showed that G.anatis had certain pathogenicity to chicks and mice.In conclusion,G.anatis was less distributed in chicken farms in southern Xinjiang,and the infection rate was 5.56%～28.85%.however,the isolates had serious drug resistance and certain pathogenicity,posing a potential threat to the health of chicken flocks and the development of poultry industry.The results provided a scientific basis for the treatment and prevention of G.anatis infection and a reference for the further study of G.anatis.