Biofilm and antimicrobial resistance profile of extended-spectrum β-lactamase (ESBL) and AmpC β-lactamase producing Enterobacteriaceae in vegetables and salads
Abeni Beshiru, Isoken H. Igbinosa, Tessy I. Enabulele, Abraham Goodness Ogofure, Adeoye John Kayode, Anthony I. Okoh, Etinosa O. Igbinosa
Abstract
This study characterized 360 vegetables and salad samples for extended-spectrum beta-lactamase (ESBL)- and AmpC-beta-lactamase-producing Enterobacteriaceae. The isolated bacteria species were processed for beta-lactamase production, antimicrobial resistance (AMR) and other virulence potentials following standard microbiological and spectrometry methods. The ESBL and AmpC-beta-lactamase-producing bacteria were positive in 16/360 (4.4%) and 4/360 (1.1%) of the vegetable samples, respectively. Molecular identification of the bacterial isolates revealed them as follows: 37 E. coli, 6 Klebsiella pneumoniae and 4 Klebsiella variicola. The total number of ESBL-producing enterobacterial phenotypes was 38, while the AmpC-beta-lactamase-producing enterobacterial phenotype was 9. The beta-lactamase-producing enterobacterial morphotypes revealed that 16/47(34.0%) were rough and moist morphotypes, 25/47(53.2%) were rough and dry morphotypes, while 6/47(12.8%) were smooth and white morphotype. The biofilm profile included strong biofilm 41(87.2%), moderate biofilm 4(8.5%) and weak biofilm 2(4.3%), as all the isolates formed biofilm on LB broth. Fourteen multi-drug resistance (MDR) phenotypes were observed in the beta-lactamase-producing E. coli isolates. A total of 40/47(85.1%) isolates had ≥1 β-lactamase gene and other AMR genes, with the blaCTX-1 being the most prevalent. Our findings conclude that food vegetables are important reservoirs of beta-lactamase-producing enterobacteria and a potential health risk to consumers of unprocessed vegetables.