1997 Volume 14 Issue 2 Pages 101-110
An outbreak of gastroenteritis due to enterohaemorrhagic E. coli O157:H7 involving 185 patients (51%) among 364 persons occurred at a primary school in Hiroshima prefecture between June 1-17, 1996. Ninety-five patients were admitted to hospital, but there were deaths. The main symptoms were abdominal pain (77.7%), diarrhea (48.6%) and headache (7.4%). In most patients, the stools were watery and contained mucocus, but hemorragic stools were rare (5/68).
On bacteriological study of stool specimens, E. coli O157:H7 was isolated from 47 patients at concentrations of 10-108 CFU/g.
The amount of VT in feces was 2-128ng/g by RPLA, and correlated with the CFU of O157:H7 in patient stool. Antibody titers against O157 LPS were between ×64 to ×2,048 (33/37) in the patient sera.
The isolates of E. coli serovar were positive for production Shiga-like toxin 1,2 and eaeA gene by PCR.
All strains showed the same plasmid profiles with 94kb, 80kb and 3.5kb plasmid DNA, and the same RAPD profiles and restriction fragment pattern by PFGE of chromosomal DNA.
