Isolation, Identification and Antimicrobial Resistance Profiling of Enterobacteriaceae (E. coli, Citrobacter spp., Salmonella spp., and Shigella spp.) Associated With Diarrheal Diseases in Fruits and Vegetables Sold at Sakubva Market, Mutare (2024–2025).

Abstract

The increase in antimicrobial-resistant (AMR) bacteria discovered in fresh produce has become a major public health concern, particularly in resource-constrained countries such as Zimbabwe. Fresh fruits and vegetables sold in open marketplaces, such as Mutare’s Sakubva Market, are frequently consumed raw, raising the risk of diarrhoea caused by pathogenic Enterobacteriaceae such as Escherichia coli, Salmonella, Citrobacter, and Shigella. Despite frequent monitoring of water sources, there is a scarcity of information on the presence and resistance patterns of these pathogens in fresh produce. This study aimed to isolate, identify, and determine the antibiotic resistance profiles of Enterobacteriaceae that cause diarrhoea in fruits and vegetables sold at Sakubva Market, in order to provide evidence for targeted public health interventions. A descriptive cross-sectional design was used, with 120 fruit and vegetable samples—including apples, mangoes, lettuce, tomatoes, carrots, and cucumbers—collected randomly from the market. Bacteria were cultured and isolated using standard microbiological methods and identified through biochemical techniques including Gram staining, indole, motility, citrate utilization, Kligler iron agar, and lysine decarboxylase tests. Antibiotic susceptibility profiles of the isolates were assessed using the disc diffusion method with routinely prescribed antibiotics. Ethical approval was obtained from both the Africa University Research Ethics Committee (AUREC) and the Mutare City Council. The findings revealed that E. coli was the most prevalent pathogen, detected in 45.8% of all samples, with lettuce showing the highest level of contamination. Salmonella Paratyphi A was the least prevalent (1.7%), while Shigella spp. were not detected in any of the tested samples. Antibiotic susceptibility testing showed high levels of resistance, with E. coli and other isolates exhibiting 100% resistance to ampicillin, gentamicin, and cotrimoxazole. Ciprofloxacin was identified as the most effective antibiotic, particularly against Citrobacter spp.. Beta-lactamase enzyme production was highest in E. coli, correlating with their multidrug resistance. These results underscore the need for improved agricultural practices, vendor hygiene, and community education to curb the transmission of AMR pathogens through fresh produce in open markets.