Fimbrial extracts from porcine enterotoxigenic Escherichia coli (ETEC) strains carrying F6 (987P) intestinal colonization factor antigen were obtained using the thermal shock method. The extracts were analyzed by SDSPAGE and immunoblotting using different fimbriae-specific antisera. Two major protein bands with molecular masses of 17.5 and 21.9 kDa were detected. The 21.9-kDa band was identified as the major subunit of F6 fimbrial antigen in strains of serogroups O9 and O141. The 17.5-kDa band was associated with porcine strains of serogroups O9 and O20. [Int Microbiol 2006; 9(4):241-246
