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Isolation and Identification of Waterborne Antibiotic-Resistant Bacteria and Molecular Characterization of their Antibiotic Resistance Genes
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Published on: March 3, 2023

Molecular characterization of multidrug-resistant Proteus mirabilis isolates from retail meat products

Shin-Hee Kim1, Cheng-I Wei, Haejung An

  • 1Department of Nutritional Sciences, College of Human Environmental Sciences, Oklahoma State University, Stillwater, Oklahoma 74078, USA. kimshin@okstate.edu

Journal of Food Protection
|July 15, 2005
PubMed

Insights

Multidrug-resistant Proteus mirabilis strains from retail meat in Oklahoma exhibit diverse antibiotic resistance patterns. Class 1 and 2 integrons, carrying various resistance genes, were identified, with resistance transferable via conjugation.

Area of Science:

  • Microbiology
  • Genetics
  • Food Safety

Background:

  • The increasing prevalence of antibiotic resistance in foodborne pathogens poses a significant public health threat.
  • Proteus mirabilis is an opportunistic pathogen that can cause various infections.

Purpose of the Study:

  • To investigate the prevalence and characteristics of multidrug-resistant Proteus mirabilis in retail meat products.
  • To identify the genetic mechanisms conferring antibiotic resistance in these isolates.
  • To assess the potential for horizontal gene transfer of resistance determinants.

Main Methods:

  • Antibiotic susceptibility testing of 64 Proteus mirabilis isolates from retail meat.
  • Genotypic analysis to detect antibiotic resistance genes and integrons (Class 1 and 2).
  • Conjugation experiments to evaluate the transferability of resistance plasmids.

Main Results:

  • Sixty-four multidrug-resistant Proteus mirabilis isolates were identified, displaying four distinct resistance patterns.
  • Common resistance observed against ampicillin, tetracycline, gentamycin, and kanamycin.
  • Class 1 integrons carrying aadA1, aadB, and aadA2 genes were prevalent. Class 2 integrons with dhfr1, sat1, and aadA1 were found in 9% of isolates.
  • Ampicillin resistance was linked to the blaTEM-1 gene. Nalidixic acid resistance was associated with gyrA and parC mutations.
  • Conjugation experiments demonstrated the transfer of plasmids containing integrons and blaTEM-1 to Escherichia coli.

Conclusions:

  • Retail meat products can harbor multidrug-resistant Proteus mirabilis with diverse resistance mechanisms.
  • Integrons and specific gene mutations play a crucial role in conferring resistance.
  • Conjugal transfer of resistance genes highlights the potential for dissemination among Enterobacteriaceae.

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