In-Vitro Antibacterial Activity of Probiotic Against Human Multidrug Resistant Pathogens

Author(s): Bhuvan Saud, Pratima Pandey, Govinda Paudel, Gunaraj Dhungana, Vikram Shrestha

Objective: Probiotics have tremendous role in human health for disease prevention and treatment in both communicable and non-communicable diseases. The aim of study is to isolate, characterize and evaluate the antibacterial effect of probiotic against Multi-drug Resistant (MDR) human bacterial pathogens.

Methodology: Total of 20 dairy (10 milk and 10 curds) samples were collected from dairy shops of Bhaktapur, Nepal. Lactobacilli spp. were isolated in de Man, Rogosa and Sharpe (MRS) agar and broth. Physiological, biochemical and tolerance tests were performed for the identification of Lactobacilli. Cell Free Supernatant (CFS) was used to determine antibacterial activity against 10 MDR bacterial species in Mueller-Hinton Agar (MHA) in in-vitro condition.

Result: Out of 20 dairy product samples, altogether 14 (4 milk and 10 curd) samples were positive for Lactobacilli spp. The antibacterial effect of CFS against MDR isolates varied. Escherichia coli, Salmonella paratyphi, Salmonella typhi, Pseudomonas spp., Staphylococcus aureus, Proteus spp., Acinetobacter, showed antibacterial effect and, Klebsiella pneumoniae and Shigella spp. did not show susceptibility. Antibacterial effect, however, was observed to be isolate specific. Among the susceptible isolates, the zone of inhibition ranged 9 mm to 16mm in diameter.

Conclusion: Out of 14 lactobacillus isolates, one isolate did not show antibacterial effect against any of the MDR isolates tested. Therefore, local dairy products of Bhaktapur contain Lactobacilli that have antibacterial effect on common human MDR bacterial pathogens.