CONTAMINATION OF THE HANDLE AND BASE OF SHOPPING CARTS BY PATHOGENIC AND MULTIDRUG RESISTANT BACTERIA

Abstract Background and Aims: Shopping carts (SCs) are considered as highly contaminated public surfaces, and may play a role in transmission of some harbor heterotrophic bacteria to human being. The purpose of the present study was to examine the hygienic conditions and presence of heterotrophic and fecal coliform bacteria on the surface of handle and base of SCs taken from shopping stores in the city of Al-Mafraq, Jordan. Methods: Five different SCs were selected randomly from four shopping stores (designated as A, B, C and D) during May through June, 2011. Two dry swab samples were taken from each SC, one from the surface of handle and another one from the surface of base. All samples were cultured on nutrient agar as none selective medium and incubated aerobically at 37 ?C for 48 hours. The developed colonies were counted and expressed as colony forming units per cm2 surface area (CFU/cm2). The isolated bacteria were characterized and identified using biochemical tests and 16S rDNA sequencing. Results: The number of heterotrophic bacteria ranged from 6 to 133 CFU/cm2 for cart handles and from 6 to 300 CFU/cm2 for cart bases, indicating higher numbers of heterotrophic bacteria in the surface of cart base. The data also revealed fluctuations in the number of heterotrophic bacteria at handles and bases of SCs. Biochemical and molecular analyses confirmed the presence of seven coliform and three noncoliform species on the surface of handle and base of SCs. These include E. coli spp., Acinetobacter calcoaceticus, Burkholderia cepacia, Yersinia enterocolitica, Tatumeella ptyseas, Pseudomonas aeruginosa, Shigella sonnei, Bacillus cereus and Bacillus pumilus. Some of these isolated species are potential pathogenic bacteria as well as multi-drug resistant bacteria. Conclusion: The presence of E. coli and other coliform bacteria on the surface of SCs indicated that poor sanitation and hygienic conditions appear to exist among the tested SCs. Appearntly, some of the isolated species can pose dangerous health risks to shoppers. The data suggested that a person using the shopping cart is more likely to be exposed to fecal bacteria on a regular basis than others. This study pleads for cleaning approaches for SCs as well as community education to promote hand hygiene, both of which are important and complementary.