Isolation and Characterization of Multidrug-Resistant Bacteria from Fresh Vegetables in Peshawar

Abstract

Background: Fresh vegetables form an essential component of a healthy diet, yet they increasingly serve as vehicles for transmitting antibiotic-resistant pathogenic bacteria to humans. This study investigated the presence of multidrug-resistant (MDR) bacteria in commonly consumed vegetables from Peshawar markets. Methods: Ten different vegetable types were collected and processed using standard microbiological techniques. Bacterial isolates were identified through colony morphology, Gram staining, and biochemical profiling. Antibiotic susceptibility testing was performed using the disc diffusion method following CLSI 2022 guidelines. Biofilm formation was assessed using the microtiter plate method, while extended-spectrum beta-lactamase (ESBL) production was detected through the double disc synergy test. Results: Five bacterial genera were isolated, including Clostridium spp., Vibrio spp., Yersinia pseudotuberculosis, Streptococcus spp., and Staphylococcus aureus. Antibiotic susceptibility testing revealed concerning resistance patterns, with most isolates showing resistance to multiple antibiotics including Augmentin and ceftazidime. Staphylococcus aureus isolated from apple gourd exhibited methicillin resistance (MRSA). All tested isolates demonstrated biofilm-forming capabilities, with relative biofilm formation values ranging from 0.07 to 0.13. ESBL production was detected in Streptococcus spp., Vibrio spp., Clostridium spp., and Yersinia pseudotuberculosis, while S. aureus was ESBL-negative. Conclusion: The presence of MDR and ESBL-producing bacteria in fresh vegetables represents a significant public health concern. These findings underscore the urgent need for improved agricultural practices, enhanced surveillance systems, and public awareness campaigns regarding vegetable safety in Peshawar.

Keywords: Multidrug-resistant bacteria, fresh vegetables, ESBL, biofilm, food safety, Peshawar.