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Phenotypic and molecular characterization of antimicrobial resistance in Proteus mirabilis isolates from dogs

Kazuki Harada1, Ayaka Niina2, Takae Shimizu1

  • 1Department of Veterinary Internal Medicine, Tottori University, Minami 4-101, Koyama-Cho, Tottori-Shi, Tottori 680-8553, Japan.

Journal of Medical Microbiology
|September 5, 2014
PubMed

Insights

Canine Proteus mirabilis in Japan shows resistance to common antibiotics like chloramphenicol and streptomycin. Surveillance is crucial as these bacteria can carry antimicrobial resistance genes, posing a potential risk.

Area of Science:

  • Veterinary Microbiology
  • Antimicrobial Resistance
  • Molecular Epidemiology

Background:

  • Proteus mirabilis is an opportunistic pathogen that can colonize companion animals.
  • Antimicrobial resistance in companion animal bacteria is a growing concern for public health.
  • Limited data exists on antimicrobial resistance mechanisms in Proteus mirabilis from dogs in Japan.

Purpose of the Study:

  • To investigate the prevalence and mechanisms of antimicrobial resistance in Proteus mirabilis strains isolated from dogs in Japan.
  • To identify specific resistance genes, integrons, and mutations associated with antimicrobial resistance.
  • To assess the potential of canine Proteus mirabilis as a reservoir for antimicrobial resistance determinants.

Main Methods:

  • Antimicrobial susceptibility testing was performed on 103 Proteus mirabilis isolates against 14 antimicrobial agents.
  • Resistant isolates were analyzed for the presence of Class 1 and Class 2 integrases.
  • Plasmid-mediated quinolone-resistance (PMQR) genes and quinolone-resistance determining regions (QRDRs) were investigated.
  • AmpC-type β-lactamases were characterized in ampicillin-resistant isolates.

Main Results:

  • High resistance rates were observed for chloramphenicol (20.4%), streptomycin (15.5%), and enrofloxacin (12.6%).
  • Class 1 and Class 2 integrons were detected in 2.9% and 11.7% of isolates, respectively.
  • The qnrD gene was identified in 1.9% of isolates, and QRDR mutations were found in 13 enrofloxacin-resistant strains.
  • AmpC-type β-lactamases (blaCMY-2, blaCMY-4, blaDHA-1) were present in three ampicillin-resistant isolates.

Conclusions:

  • Canine Proteus mirabilis strains in Japan harbor various antimicrobial resistance mechanisms, including integrons, PMQR genes, and QRDR mutations.
  • These findings highlight the importance of continued surveillance of antimicrobial resistance in companion animals.
  • This study is the first to report integrons, PMQRs, and QRDR mutations in Proteus mirabilis from companion animals in this region.

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