P-fimbriae-producing septicaemic Escherichia coli from poultry possess fel-related gene clusters whereas pap-hybridizing P-fimbriae-negative strains have partial or divergent P fimbrial gene clusters.
The organization of P fimbrial gene clusters of 13 papC-hybridizing Escherichia coli strains isolated from poultry with colisepticaemia, five P-fimbriae-expressing (P-positive) and eight P-fimbriae-non-expressing (P-negative), were examined by PCR and by Southern blot hybridization using primers or gene probes specific to the I, B, A, C or G genes. The absence of P fimbrial expression was associated with lack of PCR amplification of one or more of these genes, most commonly the I gene. Restriction endonuclease EcoRI, BamHI or PstI digests of genomic DNA from all strains hybridized with each of the gene probes and demonstrated polymorphisms between P-positive and P-negative strains. PstI digests of DNA from 12 of the 13 strains, when hybridized with the A gene probe, demonstrated a 0.1 kb fragment specific to the felA gene which encodes the major structural protein of F11 fimbriae. Hence, only the P-positive strains contained complete copies of fel-related gene clusters. In contrast, most of the pap-hybridizing P-negative strains contained partial or divergent P fimbrial gene clusters, which explains the lack of P fimbrial expression by these strains.
Dozois
C M
CM
Département de pathologie, Faculté de médecine vétérinaire, Université de Montréal, Québec, Canada.
Harel
J
J
Fairbrother
J M
JM
D000818:Animals; D016470:Bacteremia / Q000382:microbiology / Q000662:veterinary; D001426:Bacterial Proteins / Q000235:genetics; D002645:Chickens / Q000382:microbiology; D004269:DNA, Bacterial / Q000032:analysis; D004926:Escherichia coli / Q000235:genetics* / Q000472:pathogenicity; D004927:Escherichia coli Infections / Q000382:microbiology / Q000662:veterinary*; D010861:Fimbriae, Bacterial / Q000235:genetics*; D005798:Genes, Bacterial / Q000235:genetics*; D005816:Genetic Complementation Test; D005810:Multigene Family / Q000235:genetics*; D016133:Polymerase Chain Reaction / Q000379:methods; D012150:Polymorphism, Restriction Fragment Length; D011201:Poultry Diseases / Q000382:microbiology*; D014422:Turkeys / Q000382:microbiology
D001426:Bacterial Proteins; D004269:DNA, Bacterial