Study On Drug Resistance,virulence Gene Detection And Pathogenicity Of Enterococcus From Different Animals In Yinchuan

Enterococcus are normal flora that exist in the gastrointestinal tract of animals,and are also mostly often used in food or feed additives.However,in immunocompromised hosts,the bacteria can act as an opportunistic pathogen that adheres to tissues by secreting adhesins and interacts with other potentially harmful factors.It can cause various diseases such as pus uterus empyema and lamb encephalitis,and even lead to death,seriously endangering the health of animals.With the abuse and overdosage of antibacterial drugs,the resistance of Enterterococcus has increased,and multidrug resistant Enterococcus has appeared,which increased the occurrence of the disease and the difficulty of treatment.Therefore,by detecting the virulence genes and drug resistance of Enterococcus from different animals in Yinchuan,exploring the clinical pathogenicity of Enterococcus,it provides theoretical basis for veterinary clinical treatment of Enterococcus infection.This study includes three parts:1.The anal swabs were collected from different farms and pet hospitals in Yinchuan.Enterococcus was isolated and identified by colouring medium,gram staining microscopy and double PCR amplification of 16S rRNA and ent genes.Detection of 8 virulence genes of ace,asal,esp,efaA,gelE,cylA,agg,fsr by PCR.The results showed that a total of 400 strains of Enterococcus were isolated and identified.The detection rate of virulence gene esp and ace was the highest,78%and 74.75%,and the cylA gene had the lowest detection rate,15.5%,which was not detected in Enterococcus from pigs and cows.Among the four animals,the detection rate of Enterococcus virulence genes from dogs was the highest,and that of cows was the lowest.2.The sensitivity of Enterococcus to 14 antimicrobial agents was detected by disc agar diffusion method recommended by CLSI.The results showed that 400 strains of Enterococcus had the highest resistance rate to sulfamethoxazole,followed by resistance rates to cefotaxime and cefoxitin up to 99%and 96%.The sensitivity rate to levofloxacin and ampicillin were higher than 80%,all of them were sensitive to vancomycin.And the multidrug resistance of Enterococcus from pigs,chicken,cows and dogs in Yinchuan was serious,and their multidrug resistance rate were 98%,94%,92%and 98%.3.Based on the detection results of virulence genes,three strains of Enterococcus with different virulence genes were screened for mouse infection test,and their lethal dose(LD50)was determined.Pathogenic sections were used to observe and analyze the pathogenicity of the bacteria.The results showed that Enterococcus had low pathogenicity,and the LD50 of strains EV1,EV2 and EV3 were 8.71×109 cfu?2.34×1010 cfu and 9.33xlOi0 cfu.And histopathological observation showed that the congestion of the heart and vein in mice infected with poison;thickening of the alveolar interval,hemorrhage in the alveolar cavity,vascular congestion and hemorrhage;glomerular atrophy,degeneration of renal tubular epithelial cells,and renal interstitial hyperemia.Collectively,this study revealed the current status and pathogenicity of Enterococcus in different animals through the analysis of drug resistance,virulence genes and pathogenicity analysis of Enterococcus from different animals in Yinchuan.Which provided theoretical basis for guiding clinical rational drug use and laid a foundation for further study on the pathogenicity of Enterococcus.