Advances in Animal and Veterinary Sciences

Research Article
Adv. Anim. Vet. Sci. 7(s2): 63-70
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Alaa Eldin M.A. Morshdy1, Mohamed A. Hussein1, Abdallah M.A. Merwad2*, Hanan, M. El. Lawendy3, Afaf H. Mohamed3

1Department of Food Control, Faculty of Veterinary Medicine, Zagazig University, Egypt; 2Department of Zoonoses, Faculty of Veterinary Medicine, Zagazig University, Egypt; 3Department of Food Hygiene, Animal Health Research Institute, Zagazig, Provential Laboratory, Egypt.

Abstract | The present study aimed to determine phenotypic and genotypic characterization of antimicrobial resistance and some virulent genes in Staphylococcus aureus (S. aureus) isolated from ready- to- eat (RTE) food purchased from commercial restaurants at Sharkia, Egypt. One hundred RTE food including kofta, shawarma, sausage and fried shrimp were streaked on Baired-Parker agar plates followed by biochemical identification of isolates. Twenty seven S. aureus isolates were screened for antibiotic resistance by disk diffusion test. Uniplex PCR was used to detect the antimicrobial resistance genes for methicillin (mecA), beta-lactamase (blaZ), aminoglycoside [aac (6’) aph(2’’)] and macrolides (mph C) and virulence genes (spa and clfA) in four phenotypically multidrug resistant (MDR) S. aureus isolates. Furthermore, enterotoxin genes were screened in the four isolates of S. aureus using multiplex PCR. In this study, S. aureus strains showed highest resistance to methicillin and cefotaxime (100%) followed by amoxicillin (85.18%) and gentamicin (81.48%). The multiple antibiotic resistance (MAR) index of S. aureushad a range of 0.36 to 0.9 with an average 0.58. Three (25%) isolates from kofta were multi-resistant to 10 antibiotics and one strain (9.09%) of S. aureus from shawarma was resistant to 10 antimicrobials. The four isolates of phenotypically resistant S. aureus to methicillin, amoxicillin and gentamicin were positive (100%) for each of mecA, blaZ and aac (6’) aph (2’’) resistance genes; while, two isolates showed resistance to macrolides were positive for mphC gene. The four multidrug resistant (MDR) S. aureus were negative for any enterotoxin genes. Additionally, all examined MDR isolates of S. aureus from RTE food harboring spa and clfA genes (100%). The higher contamination of different RTE food with MDR S. aureus indicates improper hygienic measures. Also, the higher MAR index of S. aureus isolates has high risk potential for consumers.

Keywords | Phenotypic resistance, Staphylococcus aureus, Ready-to-Eat Food, Virulence genes, Antimicrobial resistance genes