Isolation And Identification Of Enterococcus From Cattle And Drug Resistance Analysis And Detection Of Related Genes In Part Of Ningxia

Enterococcus is a facultative anaerobic Gram-positive bacterium that belongs to the symbiotic bacteria in the gut of humans and animals and has become a major opportunistic pathogen.In Enterococcus,Enterococcus faecalis and Enterococcus faecium can cause many infections in humans and animals,such as endocarditis,sepsis,yak diarrhea,piglet arthritis and lamb encephalitis,causing economic losses to the breeding industry.The dairy farming industry in Ningxia has developed rapidly.However,with the rapid development of the daily industry in the region,the abuse of antibiotics has become more and more serious,leading to the emergence of resistant strains of Enterococcus,which poses potential harm to the development of the cattle industry and human health.Therefore,understanding the drug resistance of Enterococcus in Ningxia and timely feedback of drug resistance information is of great significance for guiding the rational use of antimicrobial drugs in clinical practice.In this experiment,samples of anal swabs from large-scale farms in Ningxia were collected,and the Enterococcus were classified and identified by using chromogenic medium and PCR method;the susceptibility of Enterococcus to 16 antimicrobial agents was determined by K-B method recommended by CLSI(2012)and multidrug resistance was analyzed.Finally,the drug resistance gene and Enterococcus virulence genes were detected by PCR.1.In 2016-2018,collect some anal swabs from dairy cows in Ningxia,and isolate and identify Enterococcus.The identification of Enterococcus was carried out by observing the morphology of bacterial colonies on the chromogenic medium of Enterococcus,Gram stain microscopy and PCR amplification of Enterococcus faecium and Enterococcus faecalis specific gene.There were 78 Enterococcus faecium and 53 Enterococcus faecalis identified.2.The 16S rRNA of other suspected Enterococcus was identified by PCR.The results showed that 255 Enterococcus were identified,of which 30.59%were Enterococcus faecalis,20.78%were Enterococcus faecium and 48.63%were other Enterococcus.3.The sensitivity test of 16 antimicrobials against 255 Enterococcus showed that the highest resistance rate to sulfisoxazole and bacitracin,reaching 100%;followed by oxacillin(92.16%),erythromycin(65.88%),tetracycline(65.49%)and penicillin(56.86%).It is highly sensitive to vancomycin and linezolid,and the sensitivity rates are 92.54%and 95.29%respectively.The isolate is resistant to up to 13 drugs.4.The detection of 9 resistance genes and 7 virulence genes in 255 Enterococcus was carried out by PCR.The results showed that the highest detection rate of aminoglycoside resistance gene aph(3)'-? was 100%;followed by the erythromycin resistance gene ermB,which was 46.27%;no vancomycin-resistant gene VanA,VanB,VanC were detected.The the highest virulence gene gelatinase gelE was 37.60%;followed by endocarditis antigen efaA,which was 36.10%.In conclusion,this study preliminarily revealed the drug resistance and the prevalence of drug resistance genes and virulence genes of Enterococcus in part of Ningxia.Through isolation and identification,drug resistance analysis and detection of drug resistance genes and virulence genes,which provided a theoretical basis for guiding clinical rational drug use and preventing the spread of drug-resistant bacteria.