Assessment of antibiotic resistance of lactic acid bacteria in Chinese fermented foods

Lactic acid bacteria isolated from 11 Chinese fermented foods were investigated for their resistance incidences of 7 clinically important antibiotics, including chloramphenicol, kanamycin, tetracycline, ciprofloxacin, ampicillin, clindamicin and erythromycin. It was found that antibiotic resistant lactic acid bacteria are widespread among traditional Chinese fermented foods and their resistance incidences depended on the raw material and manufacturing area of the foods. Resistance incidences of fermented sausages were much higher than that of fermented vegetables. Among 202 antibiotic resistant lactic acid bacterial isolates, 14 were further identified and their minimum inhibitory concentrations against 7 antibiotics were examined. Multi-resistance was observed in these 14 strains, and the presence of genes leading resistance was examined by PCR. Genes tetM and ermB were detected on both plasmid and chromosome in certain strains; gene aphA3 was only detected on plasmid while gene mefA was only on chromosome; genes gyrA, blaZ and catpIP501 were not detected. These results indicate the possible role of lactic acid bacteria as reservoirs for dissemination of antibiotic resistance in foods and the environment.