Genetic analysis of multiple antimicrobial resistance in Salmonella isolated from diseased broilers in Egypt

Authors

  • Ashraf M. Ahmed,

    1. Department of Bacteriology, Mycology and Immunology
    2. Central Diagnostic Laboratory, Faculty of Veterinary Medicine, Kafrelsheikh University, Kafr El-Sheikh 33516, Egypt
    Search for more papers by this author
  • Tadashi Shimamoto

    1. Laboratory of Food Microbiology and Hygiene, Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima 739-8528, Japan
    Search for more papers by this author

Tadashi Shimamoto, Laboratory of Food Microbiology and Hygiene, Graduate School of Biosphere Science, Hiroshima University, 1-4-4 Kagamiyama, Higashi-Hiroshima 739-8528, Japan. Tel/fax: +81 82 424 7897; e-mail: tadashis@hiroshima-u.ac.jp

ABSTRACT

To date, no information has been available on the molecular bases of antimicrobial resistance in Salmonella spp. from poultry in Egypt or even in Africa. Therefore, the objective of this study was to analyze, at the molecular level, the mechanisms of multidrug-resistance in isolates of Salmonella recovered from diseased broilers in Egypt. Twenty-one Salmonella isolates were identified; 13 of these isolates were Salmonella enterica serovar Enteritidis and eight Salmonella enterica serovar Typhimurium. 17 (81%). Salmonella isolates displayed multidrug resistance phenotypes, particularly against ampicillin, streptomycin, spectinomycin, kanamycin, tetracycline, chloramphenicol, and trimethoprim/sulfamethoxazole. PCR and DNA sequencing identified class 1 integrons in nine (42.9%) isolates and class 2 integrons in three (14.3%) isolates. The identified resistance genes within class 1 integrons were aminoglycoside adenyltransferase type A, aadA1, aadA2 and aadA5 and dihydrofolate reductase type A, dfrA1, dfrA5, dfrA12, dfrA15 and dfrA17. The β-lactamase encoding genes blaTEM-1 and blaCMY-2 and florfenicol resistance gene floR were also identified. Furthermore, the tetracycline resistance gene tet(A) was identified in 14 (66.7%) Salmonella isolates. To the best of our knowledge, this is the first report of the molecular basis of antimicrobial resistance in Salmonella spp. isolated from poultry in Africa.

Ancillary