Antigenic analysis and biochemical characters of strains of escherichia coli, commonly associated with human diarrhoea, isolated from sporadic cases of gastro-enteritis in local population of domestic animals

TLDR: Serological heterogenicity was observed within a single biotype and, similarly, strains within asingle serotype differed in their biochemical characters.

Abstract: One hundred and fifty-three strains of Escherichia coli were isolated from sporadic cases of gastroenteritis from cows, calves, buffaloes, buffalocalves, goats, and kids. Thirty-six biochemical tests were conducted. On the basis of fermentation reaction of six selected sugars (rhamnose, sucrose, dulcitol, raffinose, salicin, and starch), 153 strains were classified into 28 biotypes. Biotypes I, V, VI, XI, XVIII, and XX appeared more common than the others. These six biotypes accounted for over 60% of the total (153) strains isolated from diarrhoea, dysentery, or white scours. Biotype XX predominated in buffaloes and buffalocalves, and Type VI in cows and calves, and in goats and kids. Again Type VI predominated in diarrhoea and dysentery and Type XI in white scour. Only 137 strains could be identified serologically. Sixty-five strains belonged to 7 human enteropathogenic ‘O’ groups (O26: B6, O55: B5, O86: B7, O112: B11, O119: B14, O125: B15, and O126: B16). Group O26 predominated in goats and kids, O125 in buffaloes and buffalocalves, and O119 in cows and calves. Another 72 strains belonged to 31 ‘O’ groups, which are not known to be associated with infantile diarrhoea and gastroenteritis of human. Serological heterogenicity was observed within a single biotype and, similarly, strains within a single serotype differed in their biochemical characters.