Staphylococcus aureus and Methicillin Resistant S. aureus in Commercial Soft Drink with Antimicrobial Resistance Test on Isolates in Ethiopia

Staphylococcus aureus is common food contaminant and responsible for food poising. The aim of this study was to assess prevalence of S. aureus and Methicillin Resistant S. aureus (MRSA) in Commercial Soft Drinks (CSDs) with antimicrobial resistance test on the isolates in two towns of Ethiopia. A total of 774 samples of ready-to-drink CSDs were randomly purchases from different public supply locations and analyzed for S. aureus. MRSA were screened phenotypically using Cefoxitin (FOX 30 μg) disk diffusion method. All of studied CSD products were within manufacturer shelf life. An overall 28 (3.6%) and 5 (0.6%) S. aureus and MRSA were observed, respectively. Similar prevalence of S. aureus ranging from 1.0-4.8% and 1.2-6.6% were observed by product category and by public supply location, respectively. Significantly higher (10.7%; OR=12, 95%OR CI: 6.1-23.7) S. aureus in carton box packed than in glass bottle canned (2.3%) and metal canned (2.4%) products were observed. S. aureus prevalence was higher in CSD products from Bangladesh (17.9%; OR=21.6, 95% OR CI: 10.3-45.6) and Portugal (8.9%; OR=9.8, 95% OR CI: 3.6-26.2) than from Ethiopia (1.3%; OR=1.3, 95% OR CI: 0.5-3.3). Prevalence of MRSA ranged from 0-6.7% within studied variable. High (64.3%) S. aureus were resistant to erythromycin followed by 32.2% to ampicillin. Equal, (21.4%) of S. aureus were resistant to streptomycin, amoxicillin and chloramphenicol. All of MRSA were resistant erythromycin. Equal, 4 (80.0%) MRSA were resistant to amoxicillin and chloramphenicol. No resistant S. aureus and MRSA were observed to gentamycin and trimethoprim-sulfamethoxazole. All MRSA isolates were also not resistant to ciprofloxacin. Eighteen S. aureus isolates were resistant to at least single to multiple of six drugs used in the study. Data indicated possible contamination of CDS products with S. aureus and MRSA including MDR strain during processing and post-process handling.