THE PREVALENCE OF F107-FIMBRIAE AND THEIR ASSOCIATION WITH SHIGA-LIKETOXIN-II IN ESCHERICHIA-COLI STRAINS FROM WEANED AUSTRALIAN PIGS

A total of 480 haemolytic Escherichia coli (HEC) strains from weaned p igs were tested using an oligonucleotide probe to determine the preval ence of F107 fimbriae in Australia. Of these, 62% were positive, F107 was detected in serogroups O141, O138, O8, O45, O139, O157 and O98 but not in O149 nor O147. 81% of E. coli strains not producing other fimb riae (K88, 987P, K99 or F41) were positive for F107; 5% of strains wit h K88 fimbriae also had F107. Serological investigation of the express ion of F107 fimbriae indicated that serogroups O141, O138, O8, O45 and O157 produced variant F107ac. Variant F107ab was found on O139 strain s only. The F107 fimbrial subunits of both variants had a molecular we ight of approximately 16 kDa. A total of 350 of the HEC strains were t ested to determine the prevalence of the Shiga-like toxin II (SLT II) gene. 29.0% of these strains were positive. SLT II was detected in ser ogroups O141, O138, O149, O98, O45, O8 and 0157 but not in O139. 25% o f these strains were positive for both F107 and SLT II.