Microbial assessment of vegetables sold in selected supermarkets in Lusaka, district
The University of Zambia
Nutritionally, fresh vegetables are a good source of vitamins and essential minerals, among other nutrients. This is the main reason as to why they are consumed globally. The production of vegetables faces many constraints, especially land pressure, access to safe clean water, and low soil fertility. To satisfy the increasing demand for vegetables in view of poor soils and land pressure, farmers tend to intensify production by using sewer water, cattle and poultry manure as fertilizers. This coupled with different methods of irrigation, handling, transportation and storage, further renders fresh vegetables to be vulnerable to contamination with pathogens. Here in Lusaka vegetables are sold both in the open markets as well as supermarkets. The objective of this study was to assess whether fresh vegetables sold in selected markets in Lusaka district present a threat in terms of food borne pathogens such as salmonella and staphylococcus as well as bacteria belonging to the Enterobacteriaceae family (Total coliforms, feacal coliforms and E.coli).The bacterial isolates were further subjected to antibiotic resistance using 9 different drugs. chloramphenical, TE;Tetracycline,AMC;Amoxylcluvate,Erythromycin,Imepenem,Cefotaximine,NalidixAcid,CIP,Ciproflo xacin and Cefoxitin In this cross – sectional study, 74 vegetables where purchased from five (5) selected supermarkets and three (3) open markets in Lusaka district. Vegetable samples analysed by found the total number of fecal bacteria per 25 gram was recorded in 95% of the samples which is considerably high and a food safety risk. 94.6%) samples were found to be positive for S. aureus and (5.4%) of the samples were positive for Salmonella were as all samples were found to be contaminated with E.coli(100%). Staphylococcus aureus, 23.52% were resistant to 3 of the 6 antibiotics that were used. That is 5.88 % of the isolates showed resistance to chloramphenicol and erythromycin respectively and 11.76% showed resistance to tetracycline. Out of six (6) E. coli isolates, three (3) showed some levels of resistance to nine (9) of the antibiotics used. Only (16.67%) were resistant to amoxylcluvate, (16.67%) resistant to ampicilin and 83.33% were resistant to Tetracycline. Out of the 4 isolates belonging to salmonellae, 0nly one (1) (25.00%) showed resistance to ampicilin.The finding of resistant strains to some antibiotics was a great concern in view of food safety and public health as these vegetables have the potential of causing diarrhea diseases to consumers. Key words: Vegetables, Pathogens, antibiotics, contamination.
Vegetables--Pathogens , Vegetable production , Vegetables--Antibiotics