Enterotoxigenicity and fimbrial K88 antigenicity of Escherichia coli isolated from piglet diarrhoea

Escherichia coli strains (39) isolated from piglet diarrhoea were examined for enterotoxigenicity and K88 fimbrial antigenicity to select a suitable strain for immunoprophylactic use. Using piglet ileal loop technique for enterotoxigenicity determination, most strains of serotype O8, O.57 and O101 and one strain each of serotypes O58, O35, O51, O5, O123, O36, O9, O10, O148, O6 and O104 were found enterotoxigenic. Strains of serotypes O8, O157, O35,O101, O51 and O6 were also found capable of producing heat-stable enterotoxin (ST). All the enterotoxigenic E. coli strains were screened for the presence of K88(ab) pili by immunodiffusion test. Out of 24 enterotoxigenic E. coli strains (14 serotypes) 3 strains belonging to each of the serotypes O8 and O157 as well as 1 strain each of O51 and O6 possessed K88(ab) antigen.