Mutations in the f165(1)A and f165(1)E fimbrial genes and regulation of their expression in an Escherichia coli strain causing septicemia in pigs.
Transposon (TnphoA) mutagenesis was used to study the expression of F165(1) fimbriae, related to Prs fimbriae, in the pathogenic Escherichia coli strain 5131 (O115:K "V165":F165). This strain causes septicemia in swine and also expresses F165(2) fimbriae, related to F1C. Adhesin-defective mutants from the wild-type pathogenic strain were produced and TnphoA insertions were localized either in the f165(1)A gene, which encodes the major fimbrial subunit or in the f165(1)E, gene, which encodes a minor fimbrial subunit. TnphoA gene fusions were used to measure expression of F165(1) fimbrial genes. Similar pattern of regulation of expression was observed in both f165(1)A and f165(1)E genes. Optimal expression of F165(1) fimbriae was obtained on solid minimal medium. Production of F165(1) fimbriae was negatively regulated by addition of glucose, leucine or alanine to the media, by growth at 18 degrees C, and by pH above or below 7.0.
Daigle
F
F
Départment de Pathologie et Microbiologie, Faculté de Médecine Vétérinaire, Université de Montréal, Québec, Canada.
Dozois
C M
CM
Jacques
M
M
Harel
J
J
D000818:Animals; D004251:DNA Transposable Elements; D004926:Escherichia coli / Q000235:genetics*; D010861:Fimbriae, Bacterial / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D016254:Mutagenesis, Insertional; D018805:Sepsis / Q000382:microbiology; D013552:Swine
D004251:DNA Transposable Elements