Poultry Gastrointestinal-derived Lactic Acid Bacteria (pGIT-d-LAB) Inhibit Multiple Antibiotics Resistance Bacterial and Fungal Pathogens.

Background: To develop a probiotic formulation for poultry feed, a few poultry gastrointestinal derived lactic acid bacteria (pGIT-d-LAB) were isolated from chicken intestinal specimens and in vitro experiment was performed to evaluate their efficacy as potential probiotic candidate.
Methods: A total of 6 strains of LAB: Lactobacillus brevis ( L. brevis ), Lactobacillus acidophilus ( L. acidophilus ), Lactobacillus casei ( L. casei ), Pediococci spp, Lactobacillus fermentum ( L. fermentum ) and Lactobacillus plantarum ( L. plantarum ) were isolated and cultured for collection of Cell Free Supernatant (CFS). CFS collected was tested against pathogenic bacterial isolated from chicken feces as well as prevalent fungal pathogens, utilizing agar-well diffusion techniques. A preliminary investigation into the susceptibility of the pathogens to diverse antibiotics and antifungal drugs was conducted. Bacterial pathogens exhibiting resistance to a minimum of three classes of antibiotics were subsequently identified for pGIT-d-LAB CFS screening.
Results: The observed results revealed that the CFS derived from the isolates exhibited varying degrees of growth inhibition against different pathogens. Among the tested pGIT-d-LAB isolates, L. acidophilus demonstrated the most prominent zone of inhibition, measuring 18 mm against Klebsiella pneumoniae ZTAC 1233. Notably, Citrobacter diversus ZTAC 1255 showed resistance to all tested pGIT-d-LAB. Quantification of the metabolites produced was performed, and peak production levels was determined. L. acidophilus produced the highest amount of lactic acid (1.789 g/l ), Pediococci spp. produced the highest amount of diacetyl and H ₂ 0 ₂ (1.918 g/l ) (0.0025 g/l ) at 48 hr peak values respectively.
Conclusion: The test isolates are potential probiotic candidates for controlling pathogens in poultry.
(Copyright© 2024 Avicenna Research Institute.)