Purpose: The purpose of this study was to detect the presence of carbapenemase-producing Escherichia coli from fresh vegetables and characterize their antibiotic resistance.
Methods: Seventy-six confirmed E. coli samples were randomly chosen and tested for the presence of New-Delhi Metallo-β-lactamase (NDM) using polymerase chain reaction (PCR). Strains that showed the presence of the NDM were further tested for antibiotic resistant against seven antibiotics (Penicillin, Kanamycin, Vancomycin, Methicillin, Ceftazidime, Imipenem, and Biapenem) using the spiral gradient test (SGE).
Results: Thirty-two percent of the samples produced NDM. The MIC range was 0.4 - 16 (µg/ml) and the interpretation of the MIC value was determined according to the Clinical and Laboratory Standard Institute M100-S16 document. Overall, all tested samples where susceptible to Kanamycin. Ninety-six were resistant to Imipenem. Methicillin, Penicillin, and Vancomycin, had 82 - 88% resistant, ≤ 30% susceptibility, and no intermediate. Ceftazidine was 32% resistant and 32% susceptible to the tested samples. However, the tested samples showed 25% intermediate resistance to Ceftazidime. Biapenem had an effect on the tested samples but there were no criteria to interpret the results.
Significance: The results suggest that carbapenemase-producing E. coli is present in vegetables with potential to be resistant to commonly used antibiotics. Therefore additional safety protocols should be implemented to track vegetables and ensure their safety.