Similarity and divergence among adherent-invasive Escherichia coli and extraintestinal pathogenic E. coli strains - PubMed (original) (raw)

Similarity and divergence among adherent-invasive Escherichia coli and extraintestinal pathogenic E. coli strains

Margarita Martinez-Medina et al. J Clin Microbiol. 2009 Dec.

Abstract

Adherent-invasive Escherichia coli (AIEC) pathovar strains, which are associated with Crohn's disease, share many genetic and phenotypic features with extraintestinal pathogenic E. coli (ExPEC) strains, but little is known about the level of genetic similarity between the two pathovars. We aimed to determine the frequency of strains with the "AIEC phenotype" among a collection of ExPEC strains and to further search for a common phylogenetic origin for the intestinal and extraintestinal AIEC strains. The adhesion, invasion, and intramacrophage replication capabilities (AIEC phenotype) of 63 ExPEC strains were determined. Correlations between virulence genotype and AIEC phenotype and between intestinal/extraintestinal origin, serotype, and phylogroup were evaluated for the 63 ExPEC and 23 intestinal AIEC strains. Phylogenetic relationships between extraintestinal and intestinal AIEC strains were determined using multilocus sequence typing (MLST) and pulsed-field gel electrophoresis. Only four (6.35%) ExPEC strains, belonging to the O6:H1, O83:H1, and O25:H4 serotypes, were classified as having an AIEC phenotype. These strains were found to be genetically related to some intestinal AIEC strains of the same serotypes as revealed by MLST. No particular virulence gene sets correlated with the intestinal/extraintestinal origin of the strains or with the AIEC phenotype, whereas the gene sets did correlate with the serogroup. We identified two intestinal AIEC strains and one extraintestinal AIEC strain belonging to the O25:H4 serotype that also belonged to the emerging and virulent clonal group ST131. In conclusion, the ExPEC and AIEC pathovars share similar virulence gene sets, and certain strains are phylogenetically related. However, the majority of ExPEC strains did not behave like AIEC strains, thus confirming that the AIEC pathovar possesses virulence-specific features that, to date, are detectable only phenotypically.

PubMed Disclaimer

Figures

FIG. 1.

FIG. 1.

Correspondence analysis of the distribution of 10 virulence-associated genes (papC, sfa-focDE, afa-draBC, fimH, _fimAv_MT78, neuC, iucD, ibeA, cnf1, and hlyA) in 63 ExPEC strains and 23 intestinal AIEC strains. Eigenvalues (Eig.) and percentages of variance are provided for each axis. (A) Extraintestinal/intestinal origin of the strains and AIEC phenotype. (B) The serogroup was the sole factor that explained the segregation of the strains (only the most frequent serogroups in our collection [O6, O25, and O83] are specified). Axis 1 explains the segregation of O6 strains from the strains belonging to the O83 and O25 serogroups (P < 0.001), whereas axis 2 segregated O83 strains from the O6 and O25 serogroups (P < 0.001).

FIG. 2.

FIG. 2.

Consensus UPGMA dendrogram generated from the Dice coefficients of XbaI PFGE profiles of the four extraintestinal AIEC strains detected in this study (OL96a, PP215, PP16, and FV7563) and of the five intestinal AIEC strains with similar serotypes. Serotype, phylogroup, ST, and virulence-associated genes are specified. UC, ulcerative colitis; non-IBD, controls without IBD.

FIG. 3.

FIG. 3.

Consensus UPGMA dendrogram generated from the Dice coefficients of XbaI PFGE profiles of six O83 ExPEC strains and three O83 intestinal E. coli strains. AIEC phenotype, serotype, phylogroup, and virulence-associated genes are specified. Non-IBD: controls without IBD. The ECG-043 and ECG-009 strains were used only in this section; their characteristics are described elsewhere (34).

Similar articles

Cited by

References

    1. Abe, C. M., F. A. Salvador, I. N. Falsetti, M. A. M. Vieira, J. Blanco, J. E. Blanco, M. Blanco, A. M. O. Machado, W. P. Elias, R. T. Hernandes, and T. A. T. Gomes. 2008. Uropathogenic Escherichia coli (UPEC) strains may carry virulence properties of diarrhoeagenic E. coli. FEMS Immunol. Med. Microbiol. 52:397-406. - PubMed
    1. Barnich, N., J. Boudeau, L. Claret, and A. Darfeuille-Michaud. 2003. Regulatory and functional co-operation of flagella and type 1 pili in adhesive and invasive abilities of AIEC strain LF82 isolated from a patient with Crohn's disease. Mol. Microbiol. 48:781-794. - PubMed
    1. Barnich, N., M.-A. Bringer, L. Claret, and A. Darfeuille-Michaud. 2004. Involvement of lipoprotein NlpI in the virulence of adherent invasive Escherichia coli strain LF82 isolated from a patient with Crohn's disease. Infect. Immun. 72:2484-2493. - PMC - PubMed
    1. Baumgart, M., B. Dogan, M. Rishniw, G. Weitzman, B. Bosworth, R. Yantiss, R. H. Orsi, M. Wiedmann, P. McDonough, S. G. Kim, D. Berg, Y. Schukken, E. Scherl, and K. W. Simpson. 2007. Culture independent analysis of ileal mucosa reveals a selective increase in invasive Escherichia coli of novel phylogeny relative to depletion of Clostridiales in Crohn's disease involving the ileum. ISME J. 1:403-418. - PubMed
    1. Bidet, P., F. Mahjoub-Messai, J. Blanco, J. Blanco, M. Dehem, Y. Aujard, E. Bingen, and S. Bonacorsi. 2007. Combined multilocus sequence typing and O serogrouping distinguishes Escherichia coli subtypes associated with infant urosepsis and/or meningitis. J. Infect. Dis. 196:297-303. - PubMed

Publication types

MeSH terms

Substances

LinkOut - more resources