Three-Decade Epidemiological Analysis of Escherichia coli O15:K52:H1

• Published in: Journal of Clinical Microbiology Vol. 47; no. 6; pp. 1857 - 1862
• Main Authors: Olesen, Bente, Scheutz, Flemming, Menard, Megan, Skov, Marianne N, Kolmos, Hans Jørn, Kuskowski, Michael A, Johnson, James R
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for Microbiology 01.06.2009; American Society for Microbiology (ASM)
• Subjects: Anti-Bacterial Agents - pharmacology; Bacterial Typing Techniques; Bacteriology; Biological and medical sciences; Cluster Analysis; Drug Resistance, Bacterial; Enterobacteriaceae; Epidemiology; Escherichia coli; Escherichia coli - classification; Escherichia coli - genetics; Escherichia coli - isolation & purification; Escherichia coli - pathogenicity; Escherichia coli Infections - microbiology; Escherichia coli Proteins - genetics; Evolution, Molecular; Fimbria; Fundamental and applied biological sciences. Psychology; Genotype; Humans; Microbiology; Miscellaneous; Serotyping; Virulence Factors - genetics; Bacteria; Microbiology; Escherichia coli; Enterobacteriaceae
• ISSN: 0095-1137; 1098-660X
• DOI: 10.1128/JCM.00230-09

The successful Escherichia coli O15:K52:H1 clonal group provides a case study for the emergence of multiresistant clonal groups of Enterobacteriaceae generally. Accordingly, we tested the hypotheses that, over time, the O15:K52:H1 clonal group has become increasingly (i) virulent and (ii) resistant to antibiotics. One hundred archived international E. coli O15:K52:[H1] clinical isolates from 100 unique patients (1975 to 2006) were characterized for diverse phenotypic and molecular traits. All 100 isolates derived from phylogenetic group D and, presumptively, sequence type ST393. They uniformly carried the F16 papA allele and papG allele II (P fimbria structural subunit and adhesin variants), iha (adhesin-siderophore), fimH (type 1 fimbriae), fyuA (yersiniabactin receptor), iutA (aerobactin receptor), and kpsM II (group 2 capsule); 85% to 89% of them contained a complete copy of the pap operon and ompT (outer membrane protease). Slight additional virulence profile variation was evident, particularly within a minor diarrhea-associated subset (biotype C). However, in contrast to the clonal group's fairly stable virulence profiles over the past 30+ years, during the same interval the clonal group members' antimicrobial resistance profiles increased by a mean of 2.8 units per decade (P < 0.001). Moreover, the numbers of virulence genes and resistance markers were positively associated (P = 0.046), providing evidence against antimicrobial resistance and virulence being mutually exclusive in these strains. Thus, the O15:K52:H1 clonal group has become increasingly resistant to antimicrobials while maintaining (or expanding) its virulence potential, a particularly concerning trend if other emerging multiresistant enterobacterial clonal groups follow a similar pattern.