Detection And Drug Resistance Analysis Of Escherichia Coli Resistance Genes And Virulence Genes In Beef Cattle In Parts Of Heilongjiang Province

Escherichia coli is an important foodborne pathogen zoonosis,along with the extensive use of antibiotics,the drug resistance and serious harm,a serious threat to human and animal health.The amount of beef cattle breeding in our country in the international Third,along with the implementation of the national grain fed policy,moderate scale farming will gradually become the main industry.In recent years on dairy farms in Escherichia coli caused diarrhea,hemorrhagic enteritis and septicemia reported increasing,Escherichia coli super resistant strains and drug resistance and the harm caused by the attention.Therefore,the detection and analysis of virulence genes,resistance genes and drug resistance of Escherichia coli pathogenic bacteria from beef cattle has important practical significance for the prevention and control of colibacillosis.This study first calf diarrhea from different regions of Heilongjiang province for cattle,isolation and identification of obtain 71 strains of Escherichia coli,Through the PCR method of LEE island : eae A;Jerson island or pathogenicity island : Fyu A,irp2;Fimbriae : K88,K99,F41 F18,987P;heat labile toxin : LT;and enterotoxin Sta,Stb;hemolysin gene : hyl A,Shiga toxin : Stx1,Stx2;14 kind of virulence genes were detected.The results showed that 69% Escherichia coli strains carrying virulence genes,irp2(49.3%)gene was the highest,followed was Fyu A(47.9%).F41 and Stx1 positive rate was 15.5%,K99,hyl A,Sta positive rate was 1.41%.The LT,Stb,K88,F18,Stx2,987 P virulence genes was not to detect.The susceptibility test of 71 strains of Escherichia coli was carried out by Kirby-Bauer paper diffusion method,The results showed 71 strains of Escherichia coil on penicillin,ampicllin,tetracycline,trimethoprim and other drugs have strong resistance,including penicillin resistance rate of 98.4%,ampicillin resistance rate of 90.1%,methoxypyridine,tetracycline resistance rate of 73.2%,polymyxin resistance rate of the lowest 1.4%;polymyxin B and florfenicol more sensitive,respectively,87.3% and 60.6%.Through the PCR method of detection betalactam : bla TEM,bla SHV,bla OXA;aminoglycoside : aac(3')-IIa,aad A1,aad B;tetracycline : tet A,tet B,tet C;chloramphenicol and sulfonamides : flo R,Gyr A,Gyr B,Par C;Sul1,Sul2,in a total of 15 kinds of resistance genes.The highest detection rate of bla TEM?Gyr A and Gyr B to 98.6%,followed was tet A,Par C detection rate of 97.2%,tet B,aad A1,Sul2 detection rate was more than 80%,the lowest detection rate of tet C was about 2.8%.The positive coincidence rate of 15 resistant genotypes(except tet C)and resistant phenotype was more than 50%.In summary,the presence of multiple drug resistance and resistance gene of Heilongjiang cattle Escherichia coli isolates of common,drug resistance and resistance gene dectection rate was positively coeerlated.The majority of Escherichia coli isolated from calves with diarrhea symptoms in clinical cases a number of virulence genes.The pili virulence genes were the main K99 and F41,the enterotoxin virulence gene were main Sta.This study provides a theoretical guidance for the prevention and control of zoonotic diseases.