Epidemiological Investigation Of Enterococcus Faecalis In Some Large-scale Sheep Farms In Southern Xinjiang

Enterococci are Gram-positive symbiotic bacteria,including more than 40 kinds.Enterococcus faecalis,as an important opportunistic pathogen of iatrogenic infection,can cause endocarditis,bacteremia and sepsis in human and livestock,and seriously endanger livestock and human health.The main reason is the increase of drug resistance mechanism and virulence factors.In order to understand the infection status of sheep Enterococcus faecalis in Aksu,Kashgar and Hotan areas of Xinjiang in 2020,the samples were isolated and cultured,molecular biological identification,drug resistance analysis and detection of related drug resistance genes and virulence genes,in order to provide reference for the prevention and treatment of Enterococcus faecalis in parts of southern Xinjiang.353 samples(lung,liver,lymph node,gallbladder)were collected from some large-scale sheep farms in three regions of Xinjiang,and the bacteria were isolated and cultured.The morphological characteristics,cultural characteristics and biochemical characteristics of the isolated bacteria were identified,and they were preliminarily identified as Enterococcus faecalis.A total of 107 strains of Enterococcus faecalis were identified by PCR.The isolation rates of Enterococcus faecalis in Aksu,Kashgar and Hotan were 27.7 %(31 / 112),31 %(39 / 126)and 32.2 %(37 / 115),respectively.The virulence genes were detected.The detection rate of asal was 29.90 %(32 /107),followed by gliadin acm,and the detection rate was 17.75 %(19 / 107).The virulence genes carried in different regions were also different.Among them,74 strains carried two virulence genes in Kashgar and Hotan,5 strains carried one virulence gene in Aksu,and the detection rate of asal virulence gene in Kashgar was 56.25 %(18 / 32),followed by 43.75 %(14 / 32)in Hotan.Susceptibility test of 8 kinds of antibiotics was carried out on 107 strains of Enterococcus faecalis.The results showed that the isolated Enterococcus faecalis had different degrees of resistance to gentamicin,amikacin,tetracycline,doxycycline,erythromycin,meddimycin and cefradine,and the resistance rate was 6 %-53 %.Among them,tetracycline,meddimycin and erythromycin had higher resistance rates,which were 52.3 %,43.9 % and 33.6 %,respectively.Two of the six resistance genes were detected,which were tet M and erm B,and the detection rates were 52.30 %(56 / 107)and 58.90 %(63 /107),respectively.This study revealed that Enterococcus faecalis is prevalent in some large-scale sheep farms in southern Xinjiang,and the infection rate is high.It carries virulence genes and drug resistance genes,which pose a potential threat to sheep farms.Therefore,it is necessary to provide theoretical basis for the diagnosis,treatment and prevention of the disease.