Risk factors and occurrence of Salmonella enterica in ready-to-eat vegetable salad sold in Gombe Metropolis, Gombe State, Nigeria

Abstract

The worldwide twelve-monthly typhoid fever manifestations range amid 16–20 million ailments, ensuing in roughly 600,000 human mortalities, particularly amongst low-income and middle-income nations. Numerous typhoid outbreaks had previously been linked to contaminated vegetables. In the Gombe metropolis of Gombe state, Nigeria, ready-to-eat (RTE) vegetables are hawked around and handled using unhygienic methods. Hence, this study aimed to investigate and bridge the knowledge gap regarding the bacteriological safety of these ready-to-eat vegetables and the risk factors for their contamination with Salmonella enterica. A total of 100 samples were sourced from various locations in the Gombe metropolis, homogenized and inoculated on nutrient agar, Salmonella-Shigella agar, and MacConkey agar. Identification was executed by utilizing standard procedures of Gram’s staining and biochemical tests. Antibiotic sensitivity assessment was executed per CLSI guidelines, a questionnaire was utilized to acquire data for ascertaining the association amongst handling and contamination of the RTE vegetable salad, and this data was analyzed using a chi-square test. Findings revealed 36% of the samples were contaminated with Salmonella enterica, which were grey-white on nutrient agar, colorless colonies with black centers on Salmonella-Shigella agar, non-lactose fermenters on MacConkey agar, Gramnegative rod-shaped, motility and catalase positive, indole negative, urease negative, citrate negative, and KIA positive. Sensitivity showed the isolates were 100% sensitive to ofloxacin and chloramphenicol, 100% resistant to ceftazidime, cotrimoxazole, and ceftriaxone, but 95.4% were sensitive and 4.6% resistant to ampicillin. Data analysis revealed a significant association between contamination and some handling practices. The findings in this study have shown that the RTE vegetable salad is a source of public health hazard to the community, and also the information generated by this study can be used to create targeted health interventions against the RTE vegetable salad-transmitted typhoid in Gombe, Nigeria.