Clonal dissemination of Pseudomonas aeruginosa isolates producing extended-spectrum β-lactamase SHV-2a

Katy Jeannot1, Damien Fournier, Emeline Müller

  • 1Centre National de Référence de la Résistance aux Antibiotiques, Centre Hospitalier Régional Universitaire, Besançon, France.

Insights

A 2011 study identified 24 Pseudomonas aeruginosa strains producing the extended-spectrum beta-lactamase (ESBL) SHV-2a across 13 French hospitals. Most strains belonged to a single clone, and double-disk synergy tests effectively detected these ESBL producers.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Clinical Science

Background:

  • Extended-spectrum beta-lactamases (ESBLs) are enzymes that confer bacterial resistance to beta-lactam antibiotics.
  • Pseudomonas aeruginosa is an opportunistic pathogen frequently associated with hospital-acquired infections.
  • The emergence and spread of ESBL-producing bacteria pose a significant threat to public health.

Purpose of the Study:

  • To investigate the prevalence and clonal relatedness of Pseudomonas aeruginosa strains producing the extended-spectrum beta-lactamase SHV-2a in French hospitals.
  • To evaluate the effectiveness of double-disk synergy tests for detecting SHV-2a-producing isolates.

Main Methods:

  • Surveillance of bacterial isolates from January to December 2011 across 13 hospitals in France.
  • Identification of Pseudomonas aeruginosa strains.
  • Phenotypic detection of extended-spectrum beta-lactamase production, specifically SHV-2a.
  • Molecular typing to assess clonal relatedness.
  • Antimicrobial susceptibility testing, including double-disk synergy tests with cefepime and clavulanate.

Main Results:

  • Twenty-four Pseudomonas aeruginosa strains producing SHV-2a were identified.
  • All but one strain belonged to the same clonal type, suggesting a common source or efficient transmission.
  • Double-disk synergy tests demonstrated high sensitivity in detecting all SHV-2a-positive isolates.

Conclusions:

  • A single clone of SHV-2a-producing Pseudomonas aeruginosa was widely disseminated across multiple hospitals in France in 2011.
  • Double-disk synergy tests are a reliable and effective method for the rapid detection of SHV-2a-producing Pseudomonas aeruginosa.
  • These findings highlight the importance of ongoing surveillance and rapid diagnostic methods to control the spread of multidrug-resistant bacteria in healthcare settings.

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