Antibiotic susceptibility profiles of lactic and acetic acid bacteria isolated from ogi, yoghurt and human vagina in Nigeria

Abstract

The beneficial effects of lactic and acetic acid bacteria in human foods are well documented, however, there are increasing safety concerns associated with the exposure of humans to live microbes including transferable antibiotic resistance determinant. Therefore this study determines the antibiotic susceptibility and resistance profiles of lactic and acetic acid bacteria previously isolated from fermented foods and human vagina and the presence of plasmids in the strains. The antibiotic susceptibility and resistance of the bacterial strains was determined by disc diffusion method and the MIC for resistant strains by VITEK 2 compact system. Plasmid extraction was evaluated by ZyppyTM Plasmid Miniprep Kit while the resistant strains were cured using ethidium bromide as mutagen. All the isolates showed varying levels of antibiotic susceptibility/resistance. All the isolates were susceptible to gentamicin and resistant to vancomycin followed by ciprofloxacin. In MIC determination, only the vagina isolates showed 25% resistance to gentamicin and 75% resistance to erythromycin. Overall, only one plasmid was detected from Acetobacter pasterianus which was isolated from yoghurt with size greater than 1kb. Microbial resistance to four antibiotics (Tetracycline, Ampicillin, Sulphamethoxazole/ Trimethoprim and Neomycin) in Lactobacillus plantarum and Acetobacter pasterianus were cured. The studied isolates exhibited high degree of susceptibility to the antibiotics and the curing of the four antibiotic resistant strains indicated that the resistance may be plasmid mediated which can be transferable. Therefore the bacteria strains with cured resistance are not safe for probiotic purpose.