Bacteria and fungi co-biodeterioration of selected fresh tomatoes sold within Ungwan Rimi, Kaduna

Abstract

This study investigate the bacteria and fungi associated with the deterioration of fresh tomatoes, (Lycopersicum esculentum). A total of sixteen (16) tomato samples where obtained from four (4) different retail outlets in Ungwan Rimi area, Kaduna. The Proximate composition of the selected tomato samples were determined using standard protocol. Pour plate method was used to isolate bacteria and fungi from the tomato samples. The antibiogram of selected antibiotics and antifungal drugs against the bacteria and fungi isolates were determined using disk diffusion technique. The results of proximate composition showed that sample A had moisture content of 94.10 %, 0.74% of ash, 0.97 % of crude protein, 0.66 % of crude fat, 1.10 % crude fiber and 2.43 % of carbohydrate while sample B showed similar percentage composition of 93.89 % of moisture content, 0.86 % of ash, 1.0 % of crude protein, 0.69 % of crude fat, 1.34% of crude fibre and 2.22 % of carbohydrate. Bacteria isolated and identified were Staphylococcus aureus, Escherichia coli, and Salmonella sp. The most prevalent bacteria isolate was Staphylococcus aureus with 50% while Salmonella sp and Escherichia coli had 25% each. The fungal isolates were Penicillium sp, Aspergillus niger and Aspergillus flavus. Aspergillus niger was the most prevalent with 53.8% , Penicillium sp had 30.8%, while Aspergillus flavus had the least prevalence of 15.4%. the antibacterial susceptibility of Salmonella sp showed that it was resistant to Gentamycin, moderately sensitivity to Streptomycin and Septrin, and sensitive to Choramphenicol, Spafloxacin, Ciprofloxacin, Amoxycillin, Pefloxacin, Tarvid and Augmentine at different concentrations respectively. At different concentrations of the antibiotics, Escherichia coli was resistant to Gentamycin and Streptomycin, sensitive to Choramphenicol, Spafloxacin, Ciprofloxacin, Amoxycillin, Pefloxacin, Tarvid and Augmentine. Staphylococcus aureus was resistant to Rocephin, Zinacef and Streptomycin, moderately sensitive to Ampiclox, and Amoxicillin, and sensitive to Septrin, ciprofloxacin, Gentamycin, Pefloxacin, and erythromycin respectively. The antifungal susceptibility showed variations at different concentrations in it effect against the test fungi isolates.The presence of these fungi, as well as the bacteria isolates, which are capable of causing food poisoning, raises concern over public health risks that may be associated with the consumption of spoilt fresh tomato. Proper handling, transportation and thorough washing with clean or chlorinated water will reduce the risk of tomato spoilage associated with bacteria and fungi species.