Serogroups of Escherichia coli isolated from piglets in Spain

Serogroups of 1334 E. coli colonies isolated in Spain between 1986 and 1991 from piglets with diarrhoea, oedema disease and from healthy piglets, were determined. The serogroups determined in E. coli from diarrhoea were: O1, O2, O4, O5, O7, O8, O9, O12, O2O, O21, O23, O25, O26, O32, O39, O45, O54, O75, O78, O8O, O83, O91, O92, O1O1, O1O3, O113, O115, O116, O118, O125, O127, O138, O139, O141, O149, O153 and O157; from pigs with oedema disease: O8, O1O1, O138, O149 and O157; and from healthy piglets: O1, O2, O5, O7, O8, O9, O2O, O21, O26, O29, O45, O64, O71, O8O, O81, O91, O1O1, O1O5, O113, O115, O116, O126, O128, O132, O138, O139, O142, O146, O149, O152, O153, and O168. Serogroups O138, O141 and O149 were found to be statistically associated with enteric porcine colibacillosis (diarrhoea and oedema disease) (0.025 > P < 0.01). In addition, enterotoxigenic (ETEC) strains belonged to serogroups: O8, O9, O2O, O1O1, O138, O141 and O149; verotoxigenic (VTEC) strains to serogroups O91 and O138; and necrotizing (NTEC) strains to serogroups O2, O4, O8, O54, O78 and O83. Furthermore, 91.2% (249 out 273) of the ETEC (LT and/or STa) and/or VTEC strains belonged to only seven different serogroups. These major serogroups to which the ETEC and VTEC strains belonged, were determined in a lower percentage (21.2%) among non-toxigenic E. coli colonies isolated from sick and healthy piglets.