Assessment of Gram-negative Bacterial contamination on Supermarkets' Shopping Baskets and Trolleys in Khartoum locality

Abstract

Supermarket trolley and basket appear to be among the most contaminated objects. The present work is a descriptive cross-sectional study conducted to assess of Gram-negative bacterial contamination on supermarket shopping trolleys and baskets in Khartoum Locality. The study was conducted during the period from March to September 2014. Samples were collected from trolleys and baskets handles, by sterile cotton swabs. After collection the cotton swab part of each was broken and kept in 2ml of sterile normal saline in test tube. The tube content was transferred to the laboratory immediately. Bacterial load was determined by Pour PlateMethod. Gram-negative bacteria were identified by standard bacteriological methods including colonial morphology, Gram stain, and biochemical tests. Out of two hundred samples examined, 181 (90%) demonstrated bacterial growth. The rest, 19 (10%) failed to show any bacterial growth. Study on bacterial load revealed that the mean bacterial load was8.557×106CFU/ml. 39 Gram-negative bacteria were identified. The identified Gram-negative bacteria were as follows: Escherichia coli6 (15%),Klebsiellapneumonia 2 (5%), Pseudomonas aeruoginos 7 (18%),Shigellaspp.3(8%) andSalmonella spp.21(54%). The study concluded that the level of bacterial contamination was very high on supermarket shopping trolleys and baskets in Khartoum Locality. Improved sanitation and cleaning of these shopping trolleys and baskets by disinfectant as contained in a wipesare highly recommended. Further studies are required to validate the result of this study.