Prevalence of Pathogens and Indicator Organisms in Home Kitchens and Correlation with Unsafe Food Handling Practices and Conditions

Abstract

Despite education efforts, consumers often practice unsafe food handling and storage behaviors. Little is known about how these unsafe practices contribute to contamination of the home kitchen with foodborne pathogens. In addition, only a limited number of studies have examined the role of the kitchen as a reservoir for pathogens. The purpose of this study was to characterize microbial contamination and foodborne pathogens found in home kitchens and determine whether contamination was significantly associated with unsafe or unsanitary conditions observed in the kitchen. Swab samples were collected from food contact and preparation surfaces in homes (n = 100) in Philadelphia, PA. The samples were tested for coliforms, fecal coliforms, Escherichia coli, Staphylococcus aureus, Salmonella, Campylobacter, and Listeria. Fecal coliforms were found in 44% of homes (most often in samples from kitchen sinks, sponges, and dishcloths), and E. coli was found in 15% of homes (mostly in samples from kitchen sinks). Nearly half (45%) of the homes tested positive for a foodborne pathogen, and 12% had multiple pathogens present in the kitchen. S. aureus was isolated from 39% of homes, most often from countertops and refrigerator door handles. Listeria spp., including L. monocytogenes and L. innocua, were present in 15% of homes, most often in samples from refrigerator meat drawers. C. jejuni was isolated from 3% of homes. Contamination with Listeria was significantly associated with higher refrigerator temperatures. The contamination of surfaces with fecal coliforms and S. aureus was significantly associated with a lack of cleaning materials: dish soap and paper or cloth towels in the kitchen, and any type of towel in the nearest bathroom. The contamination of a sponge or dishcloth with either fecal coliforms or S. aureus was predictive of other surfaces in the kitchen having the same contamination, indicating that sponges and dishcloths are both reservoirs and vectors for bacteria in the kitchen.