Isolation Of E.Coli In Piglet With Diarrhea And The Prevalence Of Virulence Factor

Pathogenic Escherichia coli is one of major cause of piglet diarrhea which has been one of the most common diseases economically.To outline the E.coli isolates fr-om diarrheal piglets in Hunan province and its drug resistancen,the prevalence of vir-ulence genes,this paper has isolated 705 E.coli from piglets with diarrheal in scale pi-g farms to perform the following test:1. This test,which collects anal swab of diarrheal piglets from nine pig farms an-d PEDV (+) diarrhea diseased piglets which has preserved in the laboratory during 2 011-2014,to islate and identify E.coli of 705 strains with MacConkey plate、Gram sta-ining and PCR methods, has emploied the K-B method to check the sensitivity of di-arrheal piglets E.coli to nine kinds of drug in five types of antibiotics (tetracycline a-ntibiotics,sulfa antibiotics, aminoglycosides,quinolones,cephalosporins).The results show-ed that.Escherichia coli has lower resistance to the cephalothin,ceftriaxone,enrofloxacin and amikacin;however, Escherichia coli has higher resistance to Ofloxacin,florfenicol,d oxycycline,Compound sulfamethoxazole and streptomycin.2.Multiplex-PCR was used to determine the toxin genes (STa,STb,LT1,Stx2e,eaeA) and fimbriae genes (F4,F5,F6,F41,F18ab,F18ac) of 705 E.coli isolates.175 isolates w-ith toxin genes were detected(24.5%,175/705);57 isolates with fimbriae genes were de-tected(8.0%,57/705);22 isolates with toxin genes and fimbriae genes were detected(3. 1%,22/705);.Acorrding to the characteristic of the toxin,the 175 strains can be classifi-ed based on the toxin gene for 5 groups:ETEC,STEC,AEEC,ETEC/STEC,AEEC/STEC and they are accounting for 68.6%(120/175),37.3%(28/175),5.1%(9/175),8.6% (15/175) and 1.7%(3/175) of the toxin gene(s) positive strains of E.coli,epectively, which indicates that the prevalent E.coli type results in piglets with diarrhea is ETEC gene positive strain in Hunan aera.3.In addition,this study also has applied PCR method to detect hemolysin gene (HlyA) and HPI pathogenicity island genes (irp2),its positive rate of these 705 E.coli were as follows:8.4%(60/705) and 32.9%(235/705).