Prevalence of the enteroaggregative Escherichia coli heat-stable enterotoxin 1 gene and its relationship with fimbrial and enterotoxin genes in E-coli isolated from diarrheic piglets
C. Choi et al., Prevalence of the enteroaggregative Escherichia coli heat-stable enterotoxin 1 gene and its relationship with fimbrial and enterotoxin genes in E-coli isolated from diarrheic piglets, J VET D INV, 13(1), 2001, pp. 26-29
A total of 720 Escherichia coli strains isolated from diarrheic piglets on
756 swine farms were screened for the presence of the enteroaggregative E.
coli heat-stable enterotoxin 1 (EAST1) gene by polymerase chain reaction (P
CR). Escherichia coli strains that carried EAST1 genes were also tested by
PCR for the presence of 4 fimbriae (F4, F5, F6, F41), 2 heat-stable enterot
oxins (STa and STb), and 1 heat-labile enterotoxin (LT) gene. One hundred s
ixty-four (22.7%) of the 720 E. coli isolates carried genes for EAST1. Of t
hese 164 isolates, 62 (37.8%) carried EAST1 genes only, 11 (6.7%) carried g
enes for at least 1 of the fimbrial adhesins, 51 (31.1%) carried genes for
at least 1 of the enterotoxins, and 40 (23.8%) carried genes for at least 1
of the fimbrial adhesins and enterotoxins. Forty-six percent of strains th
at carried EAST1 genes carried STa genes, and 16% of strains that carried E
AST1 genes carried F4. The isolation rate of enterotoxigenic E. coli strain
s carrying genes for EAST1 gene was 63%. The 6 major genotypes observed in
this study (in decreasing order) were EAST1+, EAST1+STa+, EAST1+STa+STb+, E
AST1+STa+F5+, EAST1+STa+F4+, and EAST1+STb+F4+. EAST1 is widely prevalent a
mong diarrheagenic strains of E. coli and may represent an important virule
nce determinant in the pathogenesis of enteric colibacillosis of preweaned
pigs.