Escherichia coli O25b-ST131: a pandemic, multiresistant, community-associated strain.

[Sally Furniss]

J Antimicrob Chemother. 2011 Jan;66(1):1-14. Epub 2010 Nov 16.
Escherichia coli O25b-ST131: a pandemic, multiresistant, community-associated strain.

Rogers BA, Sidjabat HE, Paterson DL.
The University of Queensland, UQ Centre for Clinical Research, Herston, 4006, Brisbane, Australia.
Abstract

Escherichia coli sequence type 131 (ST131) is a worldwide pandemic clone, causing predominantly community-onset antimicrobial-resistant infection. Its pandemic spread was identified in 2008 by utilizing multilocus sequence typing (MLST) of CTX-M-15 extended-spectrum β-lactamase-producing E. coli from three continents. Subsequent research has confirmed the worldwide prevalence of ST131 harbouring a broad range of virulence and resistance genes on a transferable plasmid. A high prevalence of the clone (∼30%-60%) has been identified amongst fluoroquinolone-resistant E. coli. In addition, it potentially harbours a variety of β-lactamase genes; most often, these include CTX-M family β-lactamases, and, less frequently, TEM, SHV and CMY β-lactamases. Our knowledge of ST131's geographical distribution is incomplete. A broad distribution has been demonstrated amongst antimicrobial-resistant E. coli from human infection in Europe (particularly the UK), North America, Canada, Japan and Korea. High rates are suggested from limited data in Asia, the Middle East and Africa. The clone has also been detected in companion animals, non-companion animals and foods. The clinical spectrum of disease described is similar to that for other E. coli, with urinary tract infection predominant. This can range from cystitis to life-threatening sepsis. Infection occurs in humans of all ages. Therapy must be tailored to the antimicrobial resistance phenotype of the infecting isolate and the site of infection. Phenotypic detection of the ST131 clone is not possible and DNA-based techniques, including MLST and PCR, are described.

PMID: 21081548 [PubMed - in process]
http://www.ncbi.nlm.nih.gov/pubmed/21081548

 

[Gert van der Hoek]

Re: Escherichia coli O25b-ST131: a pandemic, multiresistant, community-associated strain.

Escherichia coli O25b-ST131: a pandemic, multiresistant, community-associated strain

Full article: http://jac.oxfordjournals.org/content/early/2010/11/17/jac.dkq415.full

- some snips -

Reservoirs of ST131

Potential reservoirs of ST131, including food or water sources, and travel from nations with a high prevalence of the clone have been proposed as explanations for the rapid emergence of the clone on multiple continents.57

To date, reservoirs have been detected only at a local level, with high carriage and infection rates in nursing-home residents in several nations.16,21

Investigations have only found sporadic isolates of ST131 amongst commercial animals and food sources, although studies are limited.32,53 The potential spread of ST131 after introduction from international travellers has only been demonstrated indirectly.

Pitout et al.45 found the highest proportion of ST131 clones amongst travellers with ESBL-producing infections in those returning from the Indian subcontinent and the Middle East.

Freeman et al.58 demonstrated a strong relationship between travel to India and community-onset CTX-M-15-producing E. coli infection in New Zealand.

Countries implicated in these reports, such as India and Pakistan, have known high rates of ESBL-producing E. coli infection, but no data on the prevalence of the ST131 clone as yet.46

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Link: Geographical distribution and antimicrobial resistance of E. coli ST131 in humans

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A clinical report of septic shock and emphysematous pyelonephritis, in a previously healthy individual with CTX-M-15-producing ST131, described the presence of these 10 virulence genes plus afa and dra (central region of Dr antigen-specific fimbriae, associated with binding and invasion in the mammalian urinary tract84).55 These latter two virulence genes occurred in ∼20% of ST131 isolates tested.10

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Given the rapid spread of the ST131 clone and its demonstrated ability to cause severe infection in otherwise healthy individuals, consideration must be given to the planning of public health measures to attempt to control infection.

A parallel could be drawn to community-associated methicillin-resistant Staphylococcus aureus. In order to successfully plan and execute interventions, we will need further information on key aspects of this pathogen and the dynamics of transmission.