Effect of commercial probiotics on the drug-resistant enteric pathogens isolated from clinical specimens

Background: Neoteric times have witnessed antibiotic resistance and the increase of infectious diseases; hence these trends lead people toward natural products. Probiotics are considered a natural source for maintaining human health from the past decades. Owing to their health benefits consuming probiotics nowadays is becoming a very popular approach for managing the digestive tract and immune health of human beings as well as promising against some human diseases. The aim of this study was to observe the inhibitory effect of probiotics on some clinically isolated drug-resistant enteric pathogens. Methods: Six commercially available probiotics (capsules) were collected from different medicine shops of Dhaka City, Bangladesh. Agar well-diffusion technique was employed to observe the antimicrobial efficacy of these samples against different pathogenic bacteria isolated from clinical specimens. Different concentrations of the probiotics were subjected to microdilution assay to determine their minimal inhibitory concentration. Results: Gram-negative bacterial pathogens such as Shigella spp., Vibrio spp., Salmonella spp., Klebsiella spp., and Pseudomonas spp. were isolated from clinical specimens. The isolates were biochemically identified and determined to be multidrug resistant. All the probiotic samples contained lactic acid bacteria as conferred by their presence on magnetic resonance spectroscopy agar media and most of them displayed significant antibacterial activity as these samples produced a zone of inhibition against the studied bacterial isolates. Conclusions: The samples showed varying degrees of effectiveness against the clinical pathogens. Luvena, Acteria, Probio, and Good gut exhibited remarkable antibacterial traits, which could effectively inhibit the growth of most of the clinical isolates. On the other hand, samples from Prolacto and Enterogermina merely had an antimicrobial effect. The minimum inhibitory concentration (MIC) value at 512 μL was found against the majority of the pathogenic isolates, while 256 μl was recorded to be the lowest MIC value. Hence, the antimicrobial efficacy of the studied samples revealed the potency of the probiotic capsules against drug-resistant enteric pathogens.