Detection of the enteroaggregative Escherichia coli heat-stable enterotoxin 1 (EAST1) gene and its relationship with fimbrial and enterotoxin markers in E. coli isolates from pigs with diarrhoea.
The presence of the astA gene responsible for production of enteroaggregative Escherichia coli heat-stable enterotoxin 1 (EAST1) was examined in E. coli strains isolated from pigs with postweaning diarrhoea. Two hundred and seven isolates were tested using PCR for the astA marker and for heat-labile I (LTI), heat-stable I (STI), and heat-stable II (STII) enterotoxin genes. Moreover, the isolates were also analysed for their serotypes (O and K antigens) as well as for fimbrial adhesins using agglutination methods. It was shown that 96 (46.4%) of the isolates possessed the astA genetic determinant. The most common EAST1-positive E. coli serotype was O149:K91 and these strains were mostly LTI/STII-positive. A close correlation between the presence of F4 fimbriae and the EAST1 gene was also observed: 88 of 96 (91.7%) astA(+) isolates tested possessed the F4 antigen. Thus, EAST1 enterotoxin may represent an additional virulence determinant playing a role in the pathogenesis of porcine colibacillosis.
Osek
J
J
Department of Microbiology, National Veterinary Research Institute, 24-100 Pulawy, Poland. josek@piwet.pulawy.pl
D000372:Agglutination Tests / Q000662:veterinary; D000818:Animals; D001427:Bacterial Toxins / Q000235:genetics* / Q000378:metabolism; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D003967:Diarrhea / Q000382:microbiology / Q000662:veterinary*; D004768:Enterotoxins / Q000235:genetics* / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics* / Q000254:growth & development / Q000472:pathogenicity; D004927:Escherichia coli Infections / Q000382:microbiology / Q000662:veterinary*; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism; D010861:Fimbriae, Bacterial / Q000235:genetics / Q000378:metabolism; D019081:O Antigens / Q000302:isolation & purification; D016133:Polymerase Chain Reaction / Q000662:veterinary; D013552:Swine; D013553:Swine Diseases / Q000382:microbiology*; D014774:Virulence
D001427:Bacterial Toxins; D004269:DNA, Bacterial; D004768:Enterotoxins; D029968:Escherichia coli Proteins; D019081:O Antigens; C034151:heat stable toxin (E coli)