ENTEROPATHOGENIC ESCHERICHIA COLI ASSOCIATED WITH DIARRHEA IN CHILDREN AND ADULTS

Enteropathogenic Escherichia coli isolated from diarrheal children and adults were studied. Twenty-two OK groups were set up as enteropathogenic Eschericha to include: O26: K60, O28a, 28c : K73, O44: K74, O55: K59, O86: K61, O86: K62, O111: K58, O112a, 112c : K66, 0119: K69, O124: K72, O125: K70, O126: K71, O127: K61, O86: K63, O128: K67, O136: K78, O143: Kx1, O144: Kx2, O146: K87, A-D (Alkalescens-Dispar) O1: K1, A-D O2: K1, A-D O3: K2, and A-D 04: K3.1. Seven hundred and eighty-nine strains of the enteropathogenic Escherichia were collected from diarrheal children and adults. OK group O124: K72 greatly exceeded any other OK group and provided 196 strains (25 %) ; O136: K78 (12.1 %) ; O44: K74 (9.2 %) ; O144: Kx2 (9.0 %) ; O86: K62 (7.0 %) ; and O28a, 28c: K73 (6.6 %) were also found frequently. Each of the remaining 16 OK groups made up 5.0 % or below of the 789 strains.2. Incidence of infection due to enteropathogenic Escherichia was established on the basis of 1076 hospitalized patients and 624 outpatients at the Municipal Ebara Hospital. The rate was compared with that of Shigella, Vibrio parahaemolyticus, Salmonella, and Entamoeba. Shigella and V. parahaemolyticus were the most frequent causative agents of dysentery in the hospitalized patients. However, the enteropathogenic Escherichia was isolated from 52 of the 458 cases which were Shigella and the vibrio free, and Salmonella from 20 other cases. When outpatients with gastroenteritis and enterocolitis were examined, enteropathogenic Escherichia was present in 44 of 624 cases, Shigella in 27, V. parahaemolyticus in 36, and Salmonella in only 4.3. The 22 Escherichia were divided into two groups, shigella-like group included 028a, 28c: K73, O112a, 112c : K66, O124: K72, O136: K78, O143: Kx1, O144 : Kx2, and 4 serotypes of A-D group and generally originated from dysentery or enterocolitis. Most strains of these OK groups or serotypes were non-motile, and possessed biochemical properties resembling those of Shigella. The remaining 12 OK groups were included in the salmonella-like group, and they were isolated from cases of gastroenteritis. The former OK groups as well as Shigella produce keratoconjunctivitis in the guinea pig, while the latter 12 OK groups as well as Salmonella do not.4. The necessity to draw attention to the possible role of enteropathogenic Escherichia in the etiology of diarrheal diseases in children and adults is discussed.