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Regional Spread of CTX-M-2-Producing Proteus mirabilis with the Identical Genetic Structure in Japan
Karin Kato1,2, Yasufumi Matsumura1, Masaki Yamamoto1
11 Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine , Kyoto, Japan .
Aims:
In this study, we analyzed the molecular epidemiology of extended-spectrum β-lactamase (ESBL)-producing Proteus mirabilis isolates collected from the central region of Japan.
Materials And Methods:
Between 2005 and 2012, 820 clinical P. mirabilis isolates were obtained from ten acute care hospitals in Japan. We characterized ESBL confirmatory test-positive isolates by sequencing the ESBL genes and their flanking regions, detecting plasmid replicons, and performing pulsed-field gel electrophoresis (PFGE).
Results:
Ninety-six isolates (12%) were positive according to the ESBL confirmatory test; all these isolates possessed blaCTX-M-2 with the same flanking structure of upstream ΔISEcp1 and a downstream region identical to downstream blaKLUA-1. IncT was the prevalent, and only, replicon found in 63 isolates. PFGE analysis detected eight clusters with more than one isolate, among which three included 56 isolates and six included isolates from multiple hospitals.
Conclusion:
CTX-M-2-producing P. mirabilis with an identical genetic structure flanking blaCTX-M-2 is dominant in this Japanese region, and there is evidence for the clonal spread of isolates.
Insights
Extended-spectrum β-lactamase (ESBL)-producing Proteus mirabilis isolates in Japan predominantly carry the blaCTX-M-2 gene with a conserved genetic structure. Evidence suggests clonal spread of these dominant ESBL-producing bacteria.
Area of Science:
- Microbiology
- Molecular Epidemiology
- Genetics
Background:
- Proteus mirabilis is a significant opportunistic pathogen.
- Extended-spectrum β-lactamase (ESBL) production in bacteria is a growing public health concern.
- Understanding the molecular epidemiology of ESBL-producing P. mirabilis is crucial for infection control.
Purpose of the Study:
- To investigate the molecular epidemiology of ESBL-producing Proteus mirabilis isolates from central Japan.
- To characterize the genetic features, including ESBL genes and their flanking regions, of these isolates.
- To assess the dissemination and genetic relatedness of the identified isolates.
Main Methods:
- Analysis of 820 clinical P. mirabilis isolates collected between 2005 and 2012 from ten Japanese hospitals.
- Sequencing of ESBL genes and flanking regions in ESBL confirmatory test-positive isolates.
- Plasmid replicon typing and pulsed-field gel electrophoresis (PFGE) for genetic characterization.
Main Results:
- 12% (96/820) of isolates were ESBL-positive.
- All ESBL-positive isolates harbored the blaCTX-M-2 gene with an identical flanking structure (upstream ΔISEcp1, downstream blaKLUA-1).
- IncT was the sole plasmid replicon identified in 63 isolates; PFGE revealed clonal spread among isolates.
Conclusions:
- CTX-M-2-producing P. mirabilis with a conserved blaCTX-M-2 genetic environment is dominant in central Japan.
- The findings indicate a potential for clonal dissemination of these specific P. mirabilis strains.
- Molecular surveillance is essential for tracking the spread of antimicrobial resistance in P. mirabilis.
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