Isolation and Molecular Characterization of Multidrug-Resistant Strains of Escherichia coli and Salmonella from Retail Chicken Meat in Japan

Authors

  • Ashraf M. Ahmed,

    1. Author Ahmed is with Dept. of Bacteriology, Mycology and Immunology, Faculty of Veterinary Medicine, Kafr El-Sheikh Univ., Kafr El-Sheikh 33516, Egypt. Authors Shimabukuro and Shimamoto are with Laboratory of Food Microbiology and Hygiene, Graduate School of Biosphere Science, Hiroshima Univ., Higashi-Hiroshima, Japan. Author Ahmed was previously with Laboratory of Food Microbiology and Hygiene, Graduate School of Biosphere Science, Hiroshima Univ., Higashi-Hiroshima, Japan. Direct inquiries to author Shimamoto (E-mail: tadashis@hiroshima-u.ac.jp).
    Search for more papers by this author
  • Hirofumi Shimabukuro,

    1. Author Ahmed is with Dept. of Bacteriology, Mycology and Immunology, Faculty of Veterinary Medicine, Kafr El-Sheikh Univ., Kafr El-Sheikh 33516, Egypt. Authors Shimabukuro and Shimamoto are with Laboratory of Food Microbiology and Hygiene, Graduate School of Biosphere Science, Hiroshima Univ., Higashi-Hiroshima, Japan. Author Ahmed was previously with Laboratory of Food Microbiology and Hygiene, Graduate School of Biosphere Science, Hiroshima Univ., Higashi-Hiroshima, Japan. Direct inquiries to author Shimamoto (E-mail: tadashis@hiroshima-u.ac.jp).
    Search for more papers by this author
  • Tadashi Shimamoto

    1. Author Ahmed is with Dept. of Bacteriology, Mycology and Immunology, Faculty of Veterinary Medicine, Kafr El-Sheikh Univ., Kafr El-Sheikh 33516, Egypt. Authors Shimabukuro and Shimamoto are with Laboratory of Food Microbiology and Hygiene, Graduate School of Biosphere Science, Hiroshima Univ., Higashi-Hiroshima, Japan. Author Ahmed was previously with Laboratory of Food Microbiology and Hygiene, Graduate School of Biosphere Science, Hiroshima Univ., Higashi-Hiroshima, Japan. Direct inquiries to author Shimamoto (E-mail: tadashis@hiroshima-u.ac.jp).
    Search for more papers by this author

Abstract

ABSTRACT:  Sixty-nine Escherichia coli and 10 Salmonella isolates, recovered from retail chicken meat in Hiroshima prefecture, Japan, were assayed for antimicrobial susceptibility, the presence of integrons and antimicrobial resistance genes. Twenty-eight out of 69 (40.6%) of E. coli and all 10 Salmonella isolates were exhibited multidrug resistance phenotypes. The most commonly reported resistance phenotypes were against ampicillin, streptomycin, spectinomycin, kanamycin, tetracycline, and trimethoprim/sulfamethoxazole. PCR screening for integrons showed that 8 (11.6%) of the E. coli isolates were positive for the class 1 integrons and 1 isolate (1.4%) was positive for the class 2 integrons. Among the 10 Salmonella isolates, 9 were positive for class 1 integrons and none was positive for class 2 integrons. The identified antibiotic resistance gene cassettes within the class 1 integrons were dfrA1, dfrA7, aadA1, aadB, and catB3, while dfrA1, sat2, and aadA1 were identified within class 2 integron. The β-lactamase resistance gene blaTEM-1 was identified in 12 (17.3%) of E. coli isolates and in only one of the Salmonella isolates. The blaCMY-2 gene, encoding AmpC β-lactamase, was detected in 16 (23.2%) of the E. coli isolates only. Conjugation experiments demonstrated that there was plasmid-mediated transfer of blaCMY-2 and blaTEM-1. These results highlighted the role of retail chicken meat as a potential source for multidrug-resistant strains of E. coli and Salmonella. To the best of our knowledge, this is the 1st report of isolation and molecular characterization of multidrug-resistant strains of E. coli from retail chicken meat in Japan.

Ancillary