ANTIMICROBIAL PHENOTYPES OF GEOGRAPHICALLY MATCHED Staphylococcus aureus ISOLATED FROM BUFFALO’S MILK AND CLINICAL HUMAN CASES IN EGYPT: POTENTIAL ZOONOTIC RISKS

Abstract

Global emergence of antibiotic-resistant food-borne pathogens is a major public health problem. This study aimed to determine the potential zoonotic risk of Staphylococcus aureus in buffalo's milk in Egypt. A total of 102 raw buffalo’s milk samples and 51 human nasal swabs were collected at Kafrelsheikh city, Egypt. All samples were examined for occurrence of S. aureus. Detected isolates were characterised based on DNase activity, mecA gene acquisition, and antibiotic resistance patterns. S. aureus was detected in 33.3% of buffalo's milk samples and29.4% of human nasal swabs. Multiple drug-resistant S.aureus (MDRSA) represented 88.2% and 90% of buffalo and human S. aureus isolates, respectively. Buffalo and human S. aureus isolates showed highest resistance rate for erythromycin (100%), and lowest resistance rate for gentamicin (22.2%). Interestingly, there was no significant difference in resistance patterns between methicillin-resistant S. aureus (MRSA) and methicillin-sensitive S. aureus (MSSA) (P<0.46 - 0.97). One-third of the detected S. aureus phenotypes (5/15, 33.3%) were identical between buffalo and human isolates. Moreover, there was no significant difference in antibiotic resistance patterns between buffalo and human isolates (P<0.1 - 0.97).This study highlights the potential public health risk of MDRSA transmission via buffalo's milk.Key words: buffalo’s milk, S. aureus, DNase, mecA, antibiogram, zoonotic risk