Antimicrobial Resistance Profiles of Bacteria Isolated from Fresh Vegetables in Free State Province, South Africa

The important role of antibiotics cannot be overestimated, as human health relies heavily on them for the treatment of infectious diseases. In this study, the antimicrobial susceptibility profiles of pathogens isolated from spinach (Spinacia oleracea) and cabbage (Brassica oleracea) collected from Free State Province were investigated. A total of 38 isolates representing 10 species, Enterobacter cloacae (5.3%), Staphylococcus aureus (13.2%), Micrococcus luteus (5.3%), Staphylococcus sciuri (5.3%), Acinetobacter haemolyticus (5.3%), Burkholderia cepacia (15.8%), Pseudomonas luteola (15.8%), Escherichia coli (18.4%), Citrobacter freundii (5.3%), and Serratia marcescens (10.5%), were confirmed by the Analytical Profile Index (API). We evaluated antibiotic resistance patterns of 38 unduplicated isolates using the disk diffusion method. As a result, E. coli (18.4%), B. cepacia (15.8%), P. luteola (15.8%), S. aureus (13.2%), and S. marcescens (10.5%), as well as 5.3% each for E. cloacae, M. luteus, S. sciuri, A. haemolyticus, and C. freundii, showed resistance to tested antibiotics. The majority (84%) of the isolates showed resistance to tetracycline, and penicillin had a value of 71%. A total of 79% of the antibiotic-resistant isolates demonstrated multidrug resistance (MDR) to several classes such as β-lactams, chloramphenicol, tetracycline, aminoglycosides, and macrolides. The results highlight the importance of monitoring the microbiological quality of leafy greens as they contain antibiotic-resistant bacteria that could affect human health when consumed.