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Published on: May 23, 2021
[Extended-spectrum beta-lactamases-producing Stenotrophomonas maltophilia strains: CTX-M enzymes detection and
J-P Lavigne1, J-B Gaillard, G Bourg
1Espri 26, Inserm, UFR de médecine, Institut national de la santé et de la recherche médicale, université Montpellier-I, Nîmes, France. jean.philippe.lavigne@chu-nimes.fr
Objective:
To study the beta-lactamases content of Stenotrophomonas maltophilia strains and to evaluate the virulence potential of these strains with the in vivo Caenorhabditis elegans model.
Methodology:
From 1st January 2006 to 31st December 2006, a monitoring programme to study multidrug resistant Gram-negative bacteria including extended-spectrum beta-lactamases (ESBL)-producing S. maltophilia was conducted at Nîmes University Hospital and Perpignan Hospital. The ESBL production was confirmed by the double-disk synergy test using ceftazidime, cefotaxime and cefepime disks associated with clavulanic acid disk. The strains were characterized phenotypically (beta-lactamase[s] identification) and genotypically (pulsed-field gel electrophoresis, plasmid analysis) and evaluated for their virulence with the in vivo nematode C. elegans model (establishment of survival curves [LT50]).
Results:
Twelve ESBL-producing S. maltophilia strains were isolated in eight patients (median age: 65 years+/-19) mainly during skin infections (41.7%). The ESBL content revealed the presence of four CTX-M-15-producing strains at the same patient. The analysis by ECP confirmed that the four strains were identical. The plasmid analysis demonstrated that the plasmid carrying CTX-M-15 in the worldwide clonal Escherichia coli O25-ST131 strain and S. maltophilia were different. The C. elegans model confirmed that S. maltophilia strains presented a low virulence potential (LT50=4.5days+/-0.5 according to the strains and nematode death in 10days+/-1) whatever their resistance.
Conclusion:
For the first time in France, a CTX-M-15-producing S. maltophilia strain has been identified. The in vivo model confirmed that these bacteria have a low potential virulence. However, these strains were isolated from "immunocompromised" and multihospital patients demonstrating the necessary monitoring of these patients. The CTX-M after diffusing in hospitals and community in E. coli strains seem to spread in other Gram-negative bacteria.
Insights
This study identified CTX-M-15 producing Stenotrophomonas maltophilia in France, revealing low virulence potential in the Caenorhabditis elegans model. Continuous monitoring is crucial for these multidrug-resistant bacteria in hospitals.
Area of Science:
- Microbiology
- Genetics
- Infectious Diseases
Context:
- Multidrug-resistant bacteria pose a significant global health threat.
- Stenotrophomonas maltophilia is an opportunistic pathogen often associated with hospital-acquired infections.
- Extended-spectrum beta-lactamases (ESBLs) are enzymes that confer resistance to important antibiotics.
Purpose:
- To characterize the beta-lactamase content of Stenotrophomonas maltophilia strains.
- To evaluate the virulence potential of these strains using the in vivo Caenorhabditis elegans model.
- To investigate the presence of CTX-M-15 producing S. maltophilia in a French hospital setting.
Summary:
- Twelve ESBL-producing S. maltophilia strains were isolated, with four strains identified as CTX-M-15 producers.
- Plasmid analysis showed distinct genetic elements for CTX-M-15 in S. maltophilia compared to Escherichia coli.
- The Caenorhabditis elegans model indicated low virulence potential for the studied S. maltophilia strains, irrespective of their resistance profiles.
Impact:
- This research marks the first identification of a CTX-M-15 producing S. maltophilia strain in France.
- The findings highlight the need for vigilant monitoring of S. maltophilia in immunocompromised and hospitalized patients.
- The study suggests the potential spread of CTX-M enzymes to other Gram-negative bacteria beyond E. coli.
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