Characterization of multidrug-resistant potential pathogens isolated from milk and some dairy products in Egypt

Dina Ashraf; Rabee A Ombarak; Ahmed Samir; Ayah B Abdel-Salam

doi:10.5455/javar.2023.j679

Characterization of multidrug-resistant potential pathogens isolated from milk and some dairy products in Egypt

J Adv Vet Anim Res. 2023 Jun 30;10(2):275-283. doi: 10.5455/javar.2023.j679. eCollection 2023 Jun.

Authors

Dina Ashraf¹, Rabee A Ombarak², Ahmed Samir¹, Ayah B Abdel-Salam³

Affiliations

¹ Department of Microbiology, Faculty of Veterinary Medicine, Cairo University, Cairo, Egypt.
² Department of Food Hygiene and Control, Faculty of Veterinary Medicine, University of Sadat City, Sadat, Egypt.
³ Department of Food Hygiene and Control, Faculty of Veterinary Medicine, Cairo University, Cairo, Egypt.

Abstract

Objective: This study aimed to explore the incidence and antimicrobial resistance (AMR) of Escherichia coli, Staphylococcus aureus, and Bacillus cereus in raw milk and some Egyptian dairy products, namely Kariesh cheese and rice with milk.

Material and methods: 112 samples (70 raw milk, 30 Kariesh cheese, and 12 rice with milk) were randomly collected from different districts in Cairo and Giza, Egypt. The samples were examined for E. coli, S. aureus, and B. cereus presence. The susceptibility of the obtained isolates was tested against 11 antimicrobials using the disk diffusion method, and further, the presence of AMR genes was examined.

Results: The incidences of E. coli, S. aureus, and B. cereus were 69.64%, 12.5%, and 16.7% in the examined samples, respectively. The antibiogram indicated that E. coli isolates (n = 60) were resistant to gentamycin (73.33%), ampicillin (AM, 53.3%), and cefotaxime (CTX, 16.66%). Multidrug-resistant (MDR) E. coli strains (n = 5) were tested for β-lactams resistance genes. bla_TEM was detected in all isolates, and two of them additionally carried bla_CTX-M. Staphylococcus aureus isolates (n = 10) were resistant to AM (100%), followed by tetracycline (TE), CTX, and gentamycin (60% each). All MDR S. aureus strains (n = 4) carried blaZ and tetK, and three of them additionally carried aac(6')-aph (2''). Bacillus cereus isolates (n = 30) showed resistance to AM (100%), amoxicillin (20%), and TE (6.66%). bla and tetA genes were detected in all MDR B. cereus isolates (n = 6).

Conclusion: Our findings denote the high incidence of potential health hazards in raw milk and some of its products and the existence of AMR bacteria, including MDR strains, which can cause human illnesses that are difficult to treat.

Keywords: Antimicrobial resistance; dairy products; potential pathogens; public health.