Detection of Methicillin-Resistant Staphylococcus aureus in Ready-to-Eat Shellfish (Corbiculid heterodont) in Bayelsa State, Nigeria

Aims/Objective: Methicillin-Resistant Staphylococcus aureus (MRSA) is a dominant cause of severe healthcare-associated (HA) infections but has recently emerged as Community-Associated (CA-MRSA) and Livestock-Associated MRSA (LA-MRSA). This study was carried out to detect the presence of Methicillin-Resistant S. aureus in Ready-to-Eat (RTE) Corbiculid heterodont in Bayelsa state, Nigeria.

Place of Study: This study was conducted in Yenagoa, Southern Ijaw and Sagbama Local Government Areas, Bayelsa State, Nigeria.

Methodology: Fifty-three samples (dried, fried and stewed) of the RTE C. heterodont were collected and subjected to standard microbiological procedures.

Results: Seventy Staphylococcus spp. were isolated, consisting of 65 (92.86%) S. aureus and 5 (7.14%) coagulase negative Staphylococcus (CONS). Out of the 65 S. aureus isolates, 53.8% were MRSA. Susceptibility pattern of MRSA showed a decreasing trend of resistance in the order: Amoxacillin, Ampicillin-Cloxacillin, Cefoxitin, and Oxacillin (100%) > Streptomycin (82.9%) >Ceftriaxone (40%) >Cefuroxime (31.4%), > Ciprofloxacin and Trimethoprim-Sulfamethoxazole (17.1%) > Gentamycin and Pefloxacin (8.6%) > Erythromycin (2.9%).Out of the 65 S. aureus isolates, 62 (95.4%) had Multidrug Resistance Index > 0.2 while 3 (4.6%) had 0.2 as their Multidrug Resistance Index. The MRSA isolates were 100% Multidrug Resistant (MDR) while the Methicillin-Sensitive S. aureus (MSSA) were 90% MDR. Molecular characterization of ten S. aureus isolates confirmed 80% S. aureus isolates and 20% CONS (S. sciuri and S. warneri). Polymerase chain reaction (PCR) and Agarose gel-electrophoresis were used to detect the presence of mecA gene, a gene that confers methicillin resistance. The mecA gene with size 500bp was identified in 50% of MRSA. This study reported presence of MRSA and MDR S. aureus in C. heterodont sold in Bayelsa state, Nigeria. This could be the avenue for the spread of MRSA. Public health awareness campaigns should be advocated to enhance hygienic practices in the handling and distribution of food.