Detection of the Shigatoxin Gene of Enterohemorrhagic Escherichia coli from Feces of Diarrheal Patients and Food Handlers by a Combination of Enrichment Culture and PCR

Abstract

The Shigatoxin genes and toxin production of 498 clinically pathogenic Escherichia coli were studied by polymerase-chain reaction (PCR) and reverse passive latex agglutination (RPLA). Of these isolates tested, 39 isolates were positive in both PCR and RPLA, 459 isolates were negative in PCR and RPLA. Moreover, feces from 521 diarrheal patients and 765 food handlers, which were collected between July of 1999 and July 2000, were tested for detection of Shigatoxin-producing Escherichia coli (STEC). Although STEC was not isolated from any of the feces by direct plating method, the Shigatoxin gene was detected in 3 (0.6%) and 2 (0.3%) of the fecal specimens from patients with diarrhea and food handler, respectively by the PCR after enrichment culture of the feces. However, STEC was not isolated from these PCR positive fecal specimens.