Distribution of enterotoxigenic Staphylococcus aureus in ready-to-eat foods in eastern Nigeria.

Out of 880 samples of commonly consumed meat, fish and vegetable ready-to-eat foods from eastern Nigeria examined, 552 (62%) yielded coagulase-positive Staphylococcus aureus, with 269 (48%) of the strains being enterotoxigenic. Two cowpea-based foods, akara and moin moin, whose methods of preparation and sale involve little or no post-processing hand contact, contained the smallest numbers of S. aureus. All the water samples from food preparation centres analysed, which had repeated hand contact during food preparation, yielded coagulase-positive S. aureus. Generally, organisms producing enterotoxin A were the most frequently encountered, followed by producers of enterotoxin B. Among fish samples, however, the predominant strains were producers of enterotoxin B and enterotoxin A, in that order. The frequency of enterotoxins C- and D-producing strains was about the same for the samples investigated.