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Title: Isolation, characterization and evaluation of anti-Salmonella probiotic potential of indigenous Lactobacilli in poultry
Authors: Khan, Imran
Keywords: Microbiology
Issue Date: 2019
Publisher: University of Veterinary and Animal Sciences, Lahore.
Abstract: Lactobacilli (n=84) were isolated from the droppings, ileum and caecum of back-yard poultry birds on De Man Rogosa and Sharpe medium. Lactobacilli isolates were screened and selected on the basis of their antimicrobial activity (6.33±0.57-20.33±1.15 mm) against Salmonella Enteritidis by well diffusion assay. In vitro characterization it was revealed that IKP23, IKP 111 and IKP 333 had pH tolerance, survival and growth in bile salts, no acquired antibiotic resistance, good auto-aggregation and co-aggregation capacity. Therefore, these three isolates were selected as potential probiotics. IKP23, IKP 111 and IKP 333 were identified as L. fermentum, L. fermentum and L. salivarius, respectively on the basis of homology of their 16S rRNA sequences. Selected isolates (IKP23, IKP 111 and IKP 333) were evaluated in vivo. For in vivo characterization, Day old broiler chicks (n=150) were randomly divided ten different groups. Group one was negative control group. Group 2 was positive control which received only the challenge bacteria (Salmonella Enteritidis) ATCC 13076 at day 07. Groups (3, 4, 5) received probiotics at day 01 to 35 and challenge bacteria at day 07 in preventive model (PM). Groups (6, 7, 8) started receiving probiotic at day 07 to day 35 and challenge bacteria at day 07 in treatment model (TM). Group 09 started receiving commercial probiotic Protexin (1g/liter) at day 01 to 35 and challenge bacteria at day 07. Group 10 started receiving antibiotic at day 01 to 05 and challenge bacteria at day 07. Birds were challenged with a single dose of ~106 CFU of Salmonella Enteritidis by oral gavage, while probiotics were administered with ~108CFU/ml daily. Weight of birds was recorded on weakly basis. Enumeration of microbes (lactobacilli, total coliforms and Salmonella) and antibodies against NDV and AIV H9 was done at different days. D-xylose absorption capacity and gut morphometric parameters (villus height, crypt depth and villus height to crypt depth ratio) were studied at day 35. Results revealed that Salmonella count (log10 CFU) was significantly increased (P˂ 0.05) in positive control group (4.88±0.29) as compared negative control (3.66±0.23). Salmonella counts were significantly lower in groups administered with IKP 23, IKP 111 and IKP 333 before Salmonella challenge (2.92±0.04, 3.05±0.10, 2.99±0.25) or after Salmonella challenge (3.37±0.12, 3.49±0.50, 3.55±0.45, respectively ) as compared to positive control group (4.88±0.29). Weight of broiler at day 35 was significantly higher (P˂ 0.05) in groups administrated with IKP 23, IKP 111 and IKP 333 prior to Salmonella challenge (1640±48.1, 1608±59.7 and 1590±49.0 gm respectively) and post Salmonella challenge (1569±45.1, 1515±47.8, and 1530±51.7 gm respectively) as compared to negative control (1466±49.6 gm), positive control group (1320±44.8 gm). Immunomodulatry effects of probiotics were higher in preventive model as compared to treatment model. Broilers administered with IKP23, IKP111 and IKP333 significantly improved villus height and villus height to crypt depth ratio as compared to positive control. D-xylose absorption was also enhanced in groups administered with probiotics. It is concluded that IKP23, IKP111 and IKP333 may have probiotic potential for poultry and these strains may prevent or competitively exclude Salmonella from poultry gut. These strains may provide additional benefit of better weight gain, improvement in gut morphometric parameters and absorption capacity in broiler challenged with Salmonella Enteritidis which insinuate for their possible role in efficient broiler production.
Gov't Doc #: 18976
Appears in Collections:PhD Thesis of All Public / Private Sector Universities / DAIs.

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