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Roer, L.

Publications and source records attributed to Roer, L..

2 recordsLinked to original sources
bioRxiv2018

Emergence of enteroaggregative Escherichia coli within the ST131 lineage as a cause of extraintestinal infections

Escherichia coli sequence type 131 (ST131) is a major cause of urinary and bloodstream infections and its association with extended-spectrum {beta}-lactamases (ESBL) significantly complicates treatment. Most notorious is its rapidly expanding H30-Rx clade (named for containing allele 30 of the type-1 fimbrial adhesin gene fimH and extensive antimicrobial resistance), which appears to have emerged in the United States due in part due to the acquisition of the ESBL-encoding blaCTX-M-15 gene and resistance to fluoroquinolones. However, non-H30 ST131 lineages with acquired CTX-M-type resistance genes also are emerging. Based on whole-genome analyses, we describe here the presence of an (fimH) H27 E. coli ST131 lineage that currently is causing an outbreak of community-acquired bacteremia and recurrent urinary tract infections (UTIs) in Denmark. This lineage has acquired both a virulence plasmid (pAA) that defines the enteroaggregative E. coli (EAEC) diarrheagenic pathotype and multiple genes associated with extraintestinal E. coli (ExPEC) that combined has made this particular ST131 lineage highly successful at colonizing its human host and cause recurrent UTI. Moreover, using a historic World Health Organization E. coli collection and publically available genome sequences, we identify a global H27 EAEC ST131 lineage dating back as far as 1998. Most H27 EAEC ST131 isolates harbor pAA or pAA-like plasmids, which analysis strongly imply was caused by a single ancestral acquisition. These findings illustrate the profound plasticity of this important pathogenic E. coli H27 lineage in general, and the genetic acquisitions of EAEC-specific virulence traits that likely confer an enhanced ability to cause intestinal colonization.\n\nImportanceThe E. coli ST131 lineage is a notorious extraintestinal pathogen. A signature characteristic of ST131 is its ability to asymptomatically colonize the gastrointestinal tract and then opportunistically cause extraintestinal infections, such as cystitis, pyelonephritis and urosepsis. In this study, we report a novel ST131 sublineage that has acquired the enteroaggregative diarrheagenic phenotype, spread across multiple continents and has been associated with multiple outbreaks of community-acquired bloodstream infections in Denmark. The strains ability to both cause diarrhea and colonize the human gastrointestinal tract may facilitate its dissemination and establishment in the community, whereas the strains clonal nature may facilitate targeted control strategies, such as vaccination.

microbiology↗
bioRxiv2018

Proficiency of WHO Global Foodborne Infections Network External Quality Assurance System participants in the identification and susceptibility testing of thermo-tolerant Campylobacter spp. from 2003-2012.

Campylobacter spp. are food- and water borne pathogens. While rather accurate estimates for these pathogens are available in industrialized countries, a lack of diagnostic capacity in developing countries limits accurate assessments of prevalence in many regions. Proficiency in the identification and susceptibility testing of these organisms is critical for surveillance and control efforts. The aim of the study was to assess performance for identification and susceptibility testing of thermo-tolerant Campylobacter among laboratories participating in the World Health Organization (WHO) Global Foodborne Infections Network (GFN) External Quality Assurance System (EQAS) over a nine year period.\n\nParticipants (primarily national level laboratories) were encouraged to self-evaluate performance as part of continuous quality improvement.\n\nThe ability to correctly identify Campylobacter spp. varied by year and ranged from 61.9 % (2008) to 90.7 % (2012), and the ability to correctly perform antimicrobial susceptibility testing (AST) for Campylobacter spp. appeared to steadily increase from 91.4 % to 93.6 % in the test period (2009-2012).\n\nPoorest performance (60.0 % correct identification and 86.8 % correct AST results) was observed in African laboratories.\n\nOverall, approximately 10 % of laboratories reported either an incorrect identification or antibiogramme. As most participants were (supra)-national reference laboratories, these data raise significant concerns regarding capacity and proficiency at the local, clinical level. Addressing these diagnostic challenges is critical for both patient level management and broader surveillance and control efforts.

microbiology↗