Molecular Characterization of Multidrug-Resistant Proteus mirabilis Isolates from Retail Meat Products
Sixty-four multidrug-resistant isolates of Proteus mirabilis were collected from retail meat products in Oklahoma. The isolates showed four different patterns of antibiotic resistance based on their resistant phenotype and genotypes. Most of these isolates were resistant to ampicillin,
tetracycline, gentamycin, and kanamycin. Class 1 integrons were detected as a common carrier of the antibiotic-resistant genes, such as aadA1, aadB, and aadA2. A few isolates (9%) contained class 2 integrons with three gene cassettes included: dhfr1, sat1, and aadA1.
These isolates were even resistant to nalidixic acid due to mutations in gyrA and parC. All ampicillin-resistant isolates contained bla
TEM-1. Plasmids that contained class 1 or 2 integrons and bla
TEM-1 were able to be transferred from P.
mirabilis isolates into Escherichia coli by conjugation, indicating that conjugal transfer could contribute to the dissemination of antibiotic resistance genes between the Enterobacteriaceae species.
Document Type: Research Article
Department of Nutritional Sciences, College of Human Environmental Sciences, Oklahoma State University, Stillwater, Oklahoma 74078
School of Pharmacy, University of Southern California, Los Angeles, California 90089, USA