Selection, characterisation and evaluation of potential probiotic Lactobacillus spp. isolated from poultry droppings

Abstract

Aim of the present study was to characterise and evaluate probiotic potential of lactobacilli isolated from indigenous poultry. Lactobacilli were isolated from poultry droppings and identified by genus specific polymerase chain reaction and 16S rRNA gene sequencing. Isolates were characterised in vitro by their ability to tolerate low pH and bile salts, phytase activity, antimicrobial activity, antibiotic susceptibility profile, and autoaggregation and coaggregation with poultry gut pathogens. In vivo evaluation of selected isolates was done by their effect on the body weight gain and immune response of broiler chicks. Total of 90, one-day old chicks, were randomly divided in 9 groups and given selected lactobacilli alone and in combinations (10 cfu/bird, daily) from day 7 to day 35. Body weight gain and humoral immune response to New Castle Disease Virus (NDV) vaccine were determined weekly. Three lactobacilli isolates (SMP52, SMP64 and SMP70) were selected as potentially probiotic bacteria on the basis of in vitro characterisation and identified as Lactobacillus crispatus, Lactobacillus casei and L. crispatus, respectively. Chicks supplemented with 'SMP52', 'SMP64', 'SMP70' and 'SMP64+SMP70' and a commercial probiotic product (Protexin) showed significantly higher mean weight gain per bird (1,584±35.2, 1,629±30.6, 1,668±34.7, 1,619±29.5 and 1,576±31.7 g/bird, respectively) as compared to negative control group (1,394±26.7 g/bird), on day 35. SMP 70 also showed significantly higher geometric mean titre against NDV vaccine at day 21 as compared to negative control. It is concluded that L. crispatus SMP52, L. casei SMP64 and L. crispatus SMP70 are potential probiotic candidates which alone or in different combinations may increase body weight of broilers.

Isolation and in vitro Characterization of Anti-Salmonella Enteritidis Probiotic Potential of Indigenous Lactobacilli from Poultry

“…Present study searched out 84 indigenous probiotic lactobacilli from poultry birds. Different researches have also reported the isolation of lactobacilli from poultry and fermented food products in Pakistan (Asghar et al, 2016;Arif et al, 2018;Saleem et al, 2018). Evaluation of in vitro probiotic potential is based upon tolerance to acidic pH and high bile salts concentration, adherence to epithelial cells, autoaggregation, co-aggregation, antibiotic resistance profile, antimicrobial and antagonistic effect against potentially pathogenic bacteria (Shokryazdan et al, 2017).…”

“…Resistance to low pH: Tolerance of lactobacilli to low pH was determined as described previously (Asghar et al, 2016). Briefly, exponentially growing isolates were resuspended (1.5×10 8 CFU/ml) in phosphate buffer saline (PBS) at different pH (2, 3, 4, 7) for 90 min.…”

“…Tolerance of isolates to bile salts was also determined as described previously (Asghar et al, 2016). Briefly, exponentially growing cultures (1%) were inoculated in MRS broth supplemented with different concentrations of bile salts (0.3%, 1.0%, and 1.8%) for 24 hours at 37°C followed by measuring the O.D.…”

“…Autoaggregation and co-aggregation of lactobacilli with S. Enteritidis were determined as described previously (Asghar et al, 2016). For auto-aggregation freshly grown Lactobacillus culture was re-suspended in PBS after centrifugation at 6000 rpm, followed by incubation at 37°C.…”

Characterization of the Culturable Subpopulations of Lactobacillus in the Chicken Intestinal Tract as a Resource for Probiotic Development

“…To our knowledge, in most studies to isolate effective probiotics in poultry as well as in other food-producing animals, the first step is isolation of strains that belong to the target taxonomic group (e.g., Lactobacillus genus), followed by a screening of the strains for various desirable phenotypes, including resistance to acidic pH or bile acid, ability to inhibit the growth of pathogenic bacteria in vitro , and particular enzymatic properties among others (Asghar et al, 2016; Kizerwetter-Świda and Binek, 2016). However, this approach has the following inherent limitations: (1) the screening is conducted with randomly picked strains from a large pool of bacterial strains, (2) the number of strains screened is critically limited due to the labor and time required for the process, and (3) the suitability of the screening criteria for in vivo efficacy remains questionable (Morelli, 2000).…”