Pathogenic genes such as
stx1,
stx2, STh gene, STp gene, LT gene,
invE,
eae,
aggR,
afaD,
astA,
cdt and
cnf were investigated in
Escherichia coli isolated from cattle during Nov. 2012 and Aug. 2013. Plural pathogenic genes were concurrently detected by multiplex PCR, and screen-positive genes were confirmed and sub-classified by PCR. Among 100 cattle investigated, 180
E. coli strains with diarrheic genes (DEC) were detected in 79 cattle, and 45 of them, isolated from 32 cattle, were Shiga toxin-producing
E. coli (STEC). More than 30% of cattle carried
astA,
cdt,
cnf and
stx2 in descending order. STh gene, LT gene,
invE,
aggR and
afaD were not detected in this study. Both
stx1 and
stx2 were concurrently detected from 6 of 45 STEC strains and
stx2 alone was detected from 19. Seventeen STEC strains carried STp gene,
astA, or
cdt along with
stx1 or
stx2. Additionally, 135 remaining DEC were classified into 18 enterotoxigenic
E. coli with STp gene, 25 enteropathogenic
E. coli with
eae, and 92 other DEC with
astA,
cdt and
cnf. Both O and H serotypes were identified in 48 strains, including O157 : H7, O1H7 and so on. O157 : H7 were identified in 3 strains that carried
stx2 and
eae together, as found in human pathogenic strains isolated from patients with gastroenteritis and hemolytic-uremic syndrome.
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