Shiga Toxin (Verotoxin)-producing Escherichia coli and Foodborne Disease:A Review

摘要

Shiga toxin (verotoxin)-producing Escherichia coli (STEC) is an important cause of foodborne disease. Since outcomes of the infections with STEC have a broad range of manifestation from asymptomatic infection or mild intestinal discomfort, to bloody diarrhea, hemolytic uremic syndrome (HUS), end-stage renal disease (ESRD), and death, the disease is a serious burden in public health and classified as a notifiable infectious disease in many countries. Cattle and other ruminants are considered to be the major reservoirs of STEC though isolation of STEC from other animals have been reported. Hence, the source of contamination extends to a wide range of foods, not only beef products but also fresh produce, water, and environment contaminated by excretes from the animals, mainly cattle. A low- infectious dose of STEC makes the disease relatively contagious, and causes outbreaks with unknown contamination sources and, therefore, as a preventive measure against STEC infection, it is important to obtain characteristics of prevailing STEC isolates in the region through robust surveillance. Analysis of the isolates by pulsed-field gel electrophoresis (PFGE) and multiple-locus variable-number tandem repeat analysis (MLVA) could help finding unrecognized foodborne outbreaks due to consumption of respective contaminated sources. However, though the results of molecular analysis of the isolates could indicate linkage of sporadic cases of STEC infection, it is hardly concluded that the cases are related via contaminated food source if it were not for epidemiological information. Therefore, it is essential to combine the results of strain analysis and epidemiological investigation rapidly to detect rapidly foodborne outbreaks caused by bacteria. This article reviews STEC infection as foodborne disease and further discusses key characteristics of STEC including pathogenesis, clinical manifestation, prevention and control of STEC infection. We also present the recent situation of the disease in Japan based on the surveillance of STEC infection.