Preliminary Studies on Isolation, Bile Tolerance and Antibiogram of Potential Probiotics (Probionts) from Locally Fermented Food Products at Beach Market, Nsukka Metropolis, Enugu State, Nigeria

Abstract

Aims: The study aims to isolate, evaluate bile tolerance and antibiogram studies of potential probiotics (Lactobacillus spp) from locally fermented Food Products (Akamu, Aqua Rafa® Yoghurt, Ogiri, Okpeye) and Kunu at Beach Market, Nsukka. Study Design: A ten - fold serial dilution and spread plate method using De Man, Rogosa and Sharpe (MRS) medium was adopted for isolation of potential Probionts. Place and Duration of Study: Department of Pharmaceutical Microbiology and Biotechnology, Faculty of Pharmaceutical Sciences, University of Nigeria Nsukka, between March - September, 2018. Methodology: Only catalase negative and Gram positive isolates characteristic of lactobacilli were used. Bile tolerance test was performed by monitoring the bacterial growth at different Bile salt concentrations (0.2%, 0.3% and 2%). The antibiogram of the isolates was assessed using the Kirby-Bauer disc diffusion method against commercial antibiotic discs of ampicillin, vancomycin, gentamycin, ciprofloxacin, methicillin and erythromycin. Results: All the 18 screened isolates were tolerant to bile salt at 0.2 % and 0.3 % with inhibition of growth at 2 % bile concentration. All isolates were observed to be resistant to methicillin (100 %) but very sensitive to gentamycin (11%) and ciprofloxacin (22%) respectively. The isolates showed intermediate resistance to other antibiotics: vancomycin (33%), erythromycin (33%) and ampicillin (44%). The decreasing pattern of resistance was thus: methicillin > ampicillin > vancomycin and erythromycin > ciprofloxacin > gentamycin. Isolates from Yoghurt (66.67%) and Ogiri (53.33%) provided most of the resistant isolates. Methicillin would provide best antagonist potential as all the isolates exhibited very high level of resistance (100 %). Conclusion: These results suggest that all the eighteen potential Lactobacillus spp strain show potential for probiotic applications and the locally fermented food products are rich sources of probionts.