PCR detection of virulence factor genes in Escherichia coli isolates from weaned piglets with edema disease and/or diarrhea in China

Fimbriae, toxins and pathogenicity islands (PAIs) are main virulence factors of the pathogenic Escherichia coli strains. To investigate into their prevalence in clinical E coli isolates associated with porcine postweaning diarrhea (P)VD) and/or pig edema disease (ED), 240 isolates were obtained from diseased piglets (140 from PWD, 76 from ED and 24 from ED/PWD) and submitted to PCR detection for genes coding for fimbriae, enterotoxins, shiga toxins, intimin and high-molecular-weight protein 2 (HMWP2). Among the 240 isolates detected, detection rates of the genes for F18, F4, intimin, HMWP2, Stx2e, LTa, STa and STb were 26.25%, 3.75%, 28.33%,16.67%, 35%, 10.83%,14.58% and 9.17%, respectively, and 67.92% of the isolates could be assigned into 20 different virulence factor patterns. Further more, F18ab(+) STEC are the prevalent pathogens of ED, and F18(+) and/or intimin(+) STEC/ETEC are the dominant pathogens of ED/PWD, while F18ab(+), W and/or intimin(+) ETEC and HPI+ and/or LEE+ E. coli are more frequently associated with PWD. (c) 2006 Elsevier B.V. All rights reserved.