Bacterial Contamination of Some Domestic and Laboratory Refrigerators in Port Harcourt Metropolis

Abstract

Background: A refrigerator is a potential source of pathogen contamination leading to food spoilage and food borne diseases. It forms an essential connection in broad chain of cross contamination which might possibly lead to the outbreaks of food borne diseases. Purpose: The aim of the study was to evaluate bacterial Contamination of Some Domestic and Laboratory Refrigerators in Port Harcourt Metropolis. Methodology: This study was done in Port Harcourt metropolis in Rivers state, Nigeria. Sterile swab sticks moistened with peptone water were used to swab the handles, bases, sides and shelves of domestic (90) and laboratory (60) refrigerators. One hundred and fifty (150) samples obtained in total were inoculated and identified using standard conventional methods of bacteria identification. Results: The results showed 100% bacterial contamination. With prevalence rates of Staphylococcus aureus(30.6%), Klebsiella pneumonia (5.3%), Vibro cholera (4.7%), Escherichia coli (4%), Salmonella typhi (3.3%), Pseudomonas aeruginosa (2%), Bacillus cereus (1.3%), Clostridium botulinium (1.3%), Shigellaspecies (1.3%), Listeria monocytogenes (1.3%), Proteus mirabilis (1.3%), Vibroparahaemolyticus (1.3%), Yersinia enterocolitica (1.3%) and Clostridium perfringens(0.7%). Chi square confirms that relationships exist between bacteria isolate with the batch sampled (chi square =139.239; df=54; p=0.00), Gram reaction (chi square =150.000; df=18; p=0.00) and the refrigerator type (chi square =35.325; df=18; p=0.00). However, no statistically significant association exists between isolates and positions on Refrigerator (chi square = 68.080; df=72; p=0.61). Conclusion: The outcome of this study confirms the presence of mesophilics and psychrotrophic bacteria in refrigerators, including potential foodborne pathogens which can cause serious health challenges. Hence, refrigerators are potential pathogen contamination sources. Therefore, proper hand hygiene, awareness and sensitization on maintenance of appropriate, good storage and refrigerator management is recommended for all.