Prevalence, Physicochemical Quality and mecA Gene Screening of Staphylococcus aureus in Commercial Kunu Drink Sold in Awka Metropolis

Background: Staphylococcus aureus is a major foodborne pathogen, often associated with antimicrobial resistance. The mec A gene, which encodes resistance to methicillin, is a key marker of resistance in S. aureus . However, there is limited information on the presence or absence of this gene in non-alcoholic beverages like kunu, a traditional fermented drink in Nigeria. This study assessed the prevalence of S. aureus in commercial kunu sold in Awka metropolis, alongside the physicochemical quality of the beverage. It also investigated the possible detection of the mecA gene to determine methicillin resistance among the isolates. Methods: Forty kunu samples were collected from different markets within Awka Metropolis, Anambra State, Nigeria, and analyzed using standard microbiological methods. Physicochemical parameters such as pH, total soluble solids (TSS), titratable acidity (TTA), protein, and carbohydrate content, were measured. S. aureus isolates were identified and subjected to antimicrobial susceptibility testing, followed by PCR screening for the mecA gene. The data were analyzed descriptively. Results: The kunu samples had pH values ranging from 3.4 to 3.8, TSS from 504.1 to 3579 mg/L, titratable acidity from 1.5 to 6.15 g/L, and protein and carbohydrate contents from 6.58 to 28.9 g/L and 15.16 to 63.2%, respectively. S. aureus was detected in 14 (35%) of the samples. Antimicrobial susceptibility testing showed that all isolates were sensitive to azithromycin, erythromycin, pefloxacin, and levofloxacin, except isolate 11, which exhibited resistance to pefloxacin and levofloxacin and intermediate resistance to ciprofloxacin. Four isolates (28.6%) were resistant to oxacillin; however, none of them harbored the mecA gene. Conclusions: Although the mecA gene was not detected, the isolation of antibiotic-resistant S. aureus from ready-to-drink kunu underscores the need for strict hygiene practices, improved production standards, and routine monitoring of this popular beverage. Further studies should explore additional resistance genes, contamination pathways, and preservation strategies to ensure microbial safety in fermented drinks.