Evaluation of antagonistic effect paraprobiotics obtained from traditional buttermilk ‘Seet’ on human pathogens

Abstract

Objective: This study aimed to evaluate the antagonistic effect of lactobacilli, commonly found in buttermilk, against four standard strains of pathogens - Staphylococcus aureus, Klebsiella pneumoniae, E. coli, Helicobacter pylori. The results showed that lactobacilli have the potential to prevent the development of a wide range of pathogens in both humans and animals(Huy et al., 2023).

Materials and Methods: Twenty-four bacterial isolates from seet (prepared from buffalo’s milk collected from 8 different dairies, in Hisar) were characterized morphologically, culturally, and biochemically, and 13 isolates of them were found to be Lactobacillus spp, belonging to 7 different species. The results of the isolates tested for catalase, oxidase, urease, nitrate reduction, MRVP, Oxidative and Fermentative, and Caesin Hydrolysis. All the strains exhibited negative tests for catalase, oxidase, urease, and nitrate reduction but showed positive fermentative and casein hydrolysis tests. We then used the antimicrobial disc diffusion method to test the samples against four pathogens: Staphylococcus aureus (ATCC-6538), Klebsiella pneumoniae (K36), E. coli (ATCC 29181), Helicobacter pylori (ATCC 43579). The effectiveness of the isolates was evaluated through a disc diffusion test on Mueller-Hinton agar medium(Zhu et al., 2023).

Results: The results obtained indicated that out of 7 species the lactobacilli strains isolated from local dairy samples, only 3 had inhibitory effects on the studied pathogens. These strains were identified as L. acidophilus, L. casei, and L. delbrueckii. All three showed moderate activity, with the exception of L. casei, and L. delbrueckii, exhibited strong activity against E. coli and H. pylori, respectively, with an inhibition zone greater than 14 mm(Wang et al., 2022).

Conclusion: The present study suggested that various types of food, pharmaceutical products, and functional foods can be produced using these bacteria(Hussain et al., 2022).