Virulence factors of Escherichia coli isolated from bovine clinical mastitis

• Published in: Veterinary microbiology 2002-02, Vol.85 (1), p.37-46
• Main Authors: Kaipainen, T., Pohjanvirta, T., Shpigel, N.Y., Shwimmer, A., Pyörälä, S., Pelkonen, S.
• Format: Article
• Language: English
• Subjects: Adhesion; aer gene; afa8D gene; afa8E gene; Animal viral diseases; Animals; Bacterial Capsules - genetics; Bacterial Outer Membrane Proteins - genetics; Bacteriology; Base Sequence; Biological and medical sciences; Blood Bactericidal Activity; Cattle; Cattle-bacteria; cnf1 gene; cnf2 gene; DNA Primers; Escherichia coli; Escherichia coli - genetics; Escherichia coli - pathogenicity; Escherichia coli Proteins - genetics; f17 gene; Fimbriae; Finland; Fundamental and applied biological sciences. Psychology; Genes, Bacterial; Infectious diseases; Israel; Mastitis; Mastitis, Bovine - microbiology; Medical sciences; Microbiology; Nephelometry and Turbidimetry - veterinary; Pancreatitis-Associated Proteins; pap gene; Pathogenicity, virulence, toxins, bacteriocins, pyrogens, host-bacteria relations, miscellaneous strains; Polymerase Chain Reaction - veterinary; sfa gene; Toxin; traT gene; Viral diseases; Virulence - genetics; Virulence factor
• ISSN: 0378-1135; 1873-2542
• DOI: 10.1016/S0378-1135(01)00483-7

Escherichia coli isolates from bovine mastitis were examined for a selection of virulence factors. The strains originated from Finland and Israel, which have differences in the proportion of mastitis caused by E. coli, clinical pictures of coliform mastitis, environmental conditions and herd management. The genes of nine virulence factors were detected by polymerase chain reaction. Presence of K1 and K5 capsules was assessed by use of specific bacteriophages. Serum resistance was tested by a turbidimetric assay. Out of 160 Finnish isolates, 37% had traT, 14% cnf2, 8% cnf1, 11% aer, 9% f17, 8% sfa, 7% pap, 1% afa8D and 1% afa8E. Out of 113 Israeli isolates, 41% had traT, 4% aer, 3% cnf2, 1% cnf1, 1% sfa and 1% f17. Some of the genes were distributed among two major pathotype groups, with either f17 family or sfa, pap and cnf1 as major determinants. Genes for F17a, CS31A, Afa7D and Afa7E were not detected. Altogether 49% of Finnish and 42% of Israeli isolates had at least one virulence gene, but genes other than traT were present in only 24% of Finnish and 5% of Israeli isolates. Serum resistance was more common among Finnish (94/160) than Israeli isolates (19/113). K1 and K5 capsules were not detected.