Study On Drug Resistance And ERIC-PCR Typing Of Enterococcus Faecalis And Escherichia Coli From Pigs And Chickens In Hunan Province

Enterococcus faecalis and Escherichia coli are commensal bacteria in human and animal intestinal tracts,and are also widely present in nature.They are often used as indicator bacteria for the occurrence of drug resistance in communities and farms.The irrational use of antibiotics is widespread,and the drug resistance of bacteria is becoming more and more serious,and because the pathogenic mechanism of bacteria is more complicated,it is more difficult to treat bacterial infections clinically.A large number of studies have shown that bacterial resistance can be spread with the spread of plasmids.It is of great significance to carry out drug resistance investigations against enterococci and E.coli in farms for the prevention and treatment of bacterial infections.This study isolated and identified Enterococcus faecalis and Escherichia coli from swines and chickens in some farms in Hunan,and tested the resistance and resistance genes of Enterococcus faecalis and E.coli from the same source.AAC(6 ')/ APH(2 ")can be transferred to E.coli,and then ERIC-PCR method was used to classify 68 Enterococcus faecalis and E.coli from the same source to get a preliminary understanding of Enterococcus faecalis in the area The drug resistance of E.coli and the type of dominant strains provide a basis for the prevention and treatment of Enterococcus faecalis and E.coli.The results of this study are as follows:(1)In this experiment,a total of 180 strains of Enterococcus faecalis and 222 strains of E.coli were isolated,in which 68 pairs of Enterococcus faecalis and E.coli were the same host.(2)The resistance of 68 pairs of Enterococcus faecalis and E.coli from the same source was determined by the drug sensitivity test paper diffusion method.The sensitivity test of 12 common antibacterial drugs was carried out on the isolated Enterococcus faecalis.The results showed that Enterococcus faecalis was severely resistant to erythromycin and clindamycin.Only one vancomycin-resistant strain was found,but no augertin and penicillin-resistant strains.11 common antimicrobial susceptibility tests were carried out on the isolated E.coli,and the results showed that the detected E.coli was severely resistant to tetracycline and sulfisoxazole.By PCR method,68 pairs of homologous Enterococcus faecalis and E.coli were tested for drug resistance genes.The results showed that the positive rate of aminoglycoside,?-lactam and macrolide drug resistance genes in Enterococcus faecalis was relatively high.no vancomycin resistance gene detected.The detection rate of tetracycline resistance genes,aminoglycoside resistance genes and sulfonamide resistance genes in E.coli is higher.(3)In the transformation and transfer experiments and the plasmid-combined transfer experiment,both the zygote and the transformant of Escherichia coli changed from being sensitive to gentamicin to drug resistance,and aac(6')-aph(2)was detected in both the transformant and the zygote gene,which proves that Enterococcus faecalis can transfer the resistance gene of aminoglycoside drugs to E.coli through transformation and combination.(4)Using ERIC-PCR method and statistical software The molecular fingerprint clustering analysis of E.coli showed that the strains with the same animal origin have high homology.Strains in the same area can be clustered into one group.Individual strains are from the same area but have low homology,and there may be a chance of infection by foreign strains.