Food safety in the domestic environment

Abstract

The main purpose of the work was to evaluate the significance of food safety in domestic environments. The prevalence and identification of food-borne pathogens were assessed by taking swabs from several points in 15 houses, such as knobs of doors, refrigerators and dishwashers, stove buttons, surfaces of preparation of foods, taps and kitchen towels, as well as from domestic animals’ feet that usually have access to the kitchen area, and WC knobs and taps. A questionnaire was also prepared and administered to the person responsible for domestic tasks in order to evaluate their experience of hygienic practices. Detection and quantification of food-borne microorganisms was made according to the methods described in the International Standards Organization (ISO), resulting in a total of 125 Enterobacteriaceae spp. isolates (19 Salmonella spp. isolates, 46 of Escherichia coli and 60 of other Enterobacteriaceae), 86 Staphylococcus coagulase-positive isolates, 5 Listeria spp. isolates and 13 Escherichia coli isolates. No Campylobacter spp. was found in the 175 analyzed samples. Antibiotic resistance to ampicillin, chloramphenicol, ciprofloxacin, gentamicin, tetracycline, nalidixic acid and trimethoprim was evaluated in the 3 major groups of the 125 isolates of Enterobacteriaceae spp. (19 Salmonella spp. isolates, 46 of Escherichia coli and 60 of other Enterobacteriaceae). Escherichia coli and Salmonella spp. showed resistance to ampicillin, chloramphenicol, tetracycline, nalidixic acid and nitrofurantoin, while other Enterobacteriaceae presented resistance only to ampicillin, trimethoprim and nitrofurantoin. Multiple antibiotic resistance occurred mainly in Escherichia coli isolates but also in Salmonella spp. and other Enterobacteriaceae; nevertheless all the isolates showed sensitivity to antibiotics of clinical importance, such as fluoroquinolones and aminoglycosides.

Date of Award	8 Aug 2012
Original language	English
Awarding Institution	Universidade Católica Portuguesa
Supervisor	Paula Teixeira (Supervisor) & Joana Gabriela Laranjeira da Silva (Co-Supervisor)