Open AccessVirulence Genotypes and Phylogenetic Background ofEscherichia coliSerogroup O6 Isolates from Humans, Dogs, and Cats
Author(s) -
James R. Johnson,
Brian Johnston,
Connie Clabots,
Michael A. Kuskowski,
Elisabeth Roberts,
Chitrita DebRoy
Publication year - 2008
Publication title -
journal of clinical microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.349
H-Index - 255
eISSN - 1070-633X
pISSN - 0095-1137
DOI - 10.1128/jcm.00674-07
Subject(s) - virulence , biology , pulsed field gel electrophoresis , multilocus sequence typing , genotype , escherichia coli , microbiology and biotechnology , phylogenetic tree , typing , cats , molecular epidemiology , virology , genetics , gene , computer science , embedded system
Molecular evidence is limited for the hypothesis that humans, dogs, and cats can become colonized and infected with similar virulentEscherichia coli strains. To further assess this possibility, archivedE. coli O6 isolates (n = 130) from humans (n = 55), dogs (n = 59), and cats (n = 16), representing the three main H (flagellar) types within serogroup O6 (H1, H7, and H31), were analyzed, along with selected reference strains. Isolates underwent PCR-based phylotyping, multilocus sequence typing, PCR-based detection of 55 virulence-associated genes, and XbaI pulsed-field gel electrophoresis (PFGE) profiling. Three major sequence types (STs), which corresponded closely with H types, accounted for 99% of the 130 O6 isolates. Each ST included human, dog, and cat isolates; two included reference pyelonephritis isolates CFT073 (O6:K2:H1) and 536 (O6:K15:H31). Virulence genotypes overlapped considerably among host species, despite statistically significant differences between human and pet isolates. Several human and dog isolates from ST127 (O6:H31) exhibited identical virulence genotypes and highly similar PFGE profiles, consistent with cross-species exchange of specificE. coli clones. In conclusion, the close similarity in the genomic backbone and virulence genotype between certain human- and animal-sourceE. coli isolates within serogroup O6 supports the hypothesis of zoonotic potential.