Enterotoxin Production and Antibiogram of Host- Adapted Variants of Staphylococcus Aureus Isolated from Ready-to-Eat Foods [Take Away Foods] and Food Handlers in Alexandria

A total of 150 random, ready-to-eat fast food [pizza and sandwiches of offal, meat, chicken, eggs and its products] as well as 50 human [nasal and hand swab] samples were collected from different restaurants and street vendors at Alexandria province. The samples were examined for the incidence of Staphylococcus aureus biotypes, which were further, studied for its enterotoxigenicity and antibiogram. [26.6%] of food samples yielded Staph aureus of which [52.5%] were enterotoxigenic, whereas [54%] of food handlers samples were positive for Staphylococcus aureus of which [29.6%] were enterotoxigenic. 70% of street vendors and 66.6% of restaurant personnel carried the organism in their noses, whereas 60% of street vendors and 26.6% of restaurant personnel carried the organism on their hands. Strains from ready-to-eat foods and food handlers could be biotyped into human, isolated bovine, ovine, avian and poultry-like biotypes. While 17.5% of food isolates and 11.1% of food handlers isolates were untypable. The majority of the isolated strains were belonged to the human, biotype which produced enterotoxins more frequently than the other biotypes [50% of restaurant foods and 66.6% of restaurant personnel isolates] and [63.6% of street-vended foods and 100% of street vendors isolates]. Strains of the human biotype isolated from all sources produced staphylococcal enterotoxin A [SEA] in particular, while strains of the bovine and ovine ones are less frequently enterotoxigenic and produced SEB, SEC and SED. The avian and poultry-like biotypes were non-enterotoxin producers, Multiproducing strains, which could produce two or three types of SE, were prevalent in food samples especially street-vended foods. The majority of strains were sensitive to vancomycin[97.5% of food and 100% of food handlers' isolates] followed by gentamicin ,streptomycin, penicillin, and ciprofloxacin. Nearly similar sensitivity to oxacillin and tetracycline was observed in both food and food handler's isolates. Food handlers isolates exhibited a somewhat lower sensitivity to methicillin than food isolates. The lowest percentage of sensitivity was displayed to thiamphenicol in both food and food handlers’ isolates. Multiple antibiotic resistances were observed among the isolated strains. The majority of multi-drug-resistant isolates [40% of food and 37% of food handlers] had a resistance against both tetracycline and oxacillin.