Molecular Characterization of Enterotoxigenic Escherichia coli in Foodborne Outbreak

Diarrheagenic Escherichia coli (E. coli) is a main cause of diarrhea worldwide. This study reports the investigation on the occurrence of enterotoxigenic E. coli (ETEC) serotype O27:H7-associated foodborne gastrointestinal disease that occurred at two schools, one middle school and one high school, in Seoul, Korea in June 2015. The immediate government investigation in 1,216 students and 19 food handlers in these two schools revealed that 116 students, 32 students in the middle school and 84 students in the high school, and 2 food handlers, one from middle school and the other from high school, developed gastrointestinal illness symptoms including diarrhea. Following lab investigation identified 29 ETEC serotype O27:H7 strains, 27 from 116 students and 2 from 19 food handlers. Pattern of pulsed-field gel electrophoresis analysis of ETEC isolates suggested that ETEC serotype O27:H7 caused the diarrheal outbreak in June 2015 in Seoul, Korea was a specific clone. In addition, these ETEC serotype O27:H7 isolates were highly resistance to the several antibiotics. The results from the present study provide the evidence that ETEC serotype O27:H7 can be an important cause of domestic foodborne outbreak in Korea.

Molecular Characterization of Norovirus and Rotavirus in Outbreak of Acute Gastroenteritis in Seoul

Norovirus and rotavirus are important causes of acute nonbacterial gastroenteritis in communities worldwide. Genotypes of norovirus and rotavirus in stool samples, which were collected from patients, was determined by RT-PCR and ELISA. A total 4,484 stool samples (461 outbreak cases) collected during January 2010-April 2013 were analyzed. Four hundred thirty eight of samples were positive for norovirus. Twelve samples were positive for Rotavirus. Norovirus genotypes identified were nine kinds of G I genotype (G I -1, G I -2, G I -3, G I -4, G I -6, G I -7, G I -9, G I -12, G I -13) and nine kinds of G II genotype(G II -2, G II -4, G II -5, G II -6, G II -7, G II -11, G II -12, G II -15, G II -16). Rotavirus genotypes were G2P[4]. The results might be useful information for evaluating the epidemiological status of viral diarrhea in Seoul, and providing a strategy to prevent human norovirus, rotavirus and other threats to public health in Korea.