Joshua Angelo H. Mandanas | Leslie Michelle M. Dalmacio | Marilen P. Balolong
Vibrio spp. with antibiotic resistance phenotypes were previously isolated from Manila Bay and is considered a possible threat to public health. Lactic acid bacteria (LAB), the commonly used microorganisms in food fermentation and a natural, sustainable flavor enhancer, secrete metabolites that have antimicrobial activities. It is then worth exploring the potential of these metabolites against pathogens from environmental reservoirs. This study determined the inhibitory effects of crude cell-free supernatant (CFS) and ammonium sulfate precipitate (ASP) preparations from Lactobacillus plantarum BS25 (LP) and Pediococcus acidilactici S3 (PA) against antibiotic-resistant Vibrio alginolyticus (P3) and Vibrio fluvialis (0405-W4-01-02) isolates. Resazurin assay showed that CFS and ASP from LP and PA can inhibit antibiotic resistant strains of Vibrio spp. isolates with the highest recorded activity against Vibrio fluvialis. Preparations of putative bacteriocins of 123 mg/mL from 1.94 x 10¹² CFU/mL PA (CFS) exhibited 92% inhibition while 86 mg/mL from 1.703 x 10¹² CFU/mL LP (ASP) showed 99% inhibition against 1.87 x 10¹² CFU/mL of Vibrio fluvialis (50 uL and 40uL, respectively). The activities observed were higher compared to the control (225 ppm) tetracycline by 6% and 66% (a=0.05, p < 0.00001), respectively. Total protein content from ASP preparation of LP (0.012 mg/mL) and PA (0.016 mg/mL) were determined using Bradford assay. Putative class I and III bacteriocins were observed in SDS-PAGE bands of LP (10kDa, 37kDA to 75 kDa) and PA (10kDa, 37 to 100kDa), respectively. Putative bacteriocins from LP and PA have inhibitory effects against antibiotic-resistant Vibrio spp. Results of the study can be used in the development of postbiotics against antibiotic-resistant pathogens isolated from environmental reservoirs.
ISSN 2719-1990 (Print)
Philippine E-Journals
