The Efficiency of Bacteriophages Against Salmonella Typhimurium Infection in Native Noi Broilers

Abstract

Though recently considered a therapeutic treatment for commercial broilers, little is known about the effects of bacteriophages on native, slow-growing birds. This study evaluated their efficacy against Salmonella enterica subsp. enterica serovar Typhimurium infected Noi chicken, a native Vietnamese broiler breed. In total, 420 birds were used in a completely randomized design consisting of seven treatments and four replicates of 15 birds. The treatments were NC (negative control), PC (positive control, S. Typhimurium challenged); NC+B1 and NC+B2 (negative control plus B1 or B2 bacteriophage, respectively); PC+B1, PC+B2 (positive control plus B1 or B2 bacteriophage, respectively) and PC+B1B2 (positive control plus both B1 and B2 bacteriophages). After four weeks of infection, the mortality rate in the PC group was 51.1% compared with 11.1% in the PC+B1B2 treatment. Bacteriophage administration had resulted in increased weight gain and decreased feed conversion ratio, particularly when both phages were included in the treatment (p<0.001). Moreover, the relative percentage of carcass weight was lowest in the PC treatment (66.9%) (p<0.001), whereas the other treatments registered similar carcass weight values. Regarding the internal organs, liver weight percentage was higher in the non-treated Salmonella group, and enlarged spleens were also noted in infected chickens even when treated with bacteriophages. The correlation between phage administration and blood parameters was unclear. Although the use of two bacteriophages for therapy was determined to be preferable for the majority of the criteria examined, further genetic characterization of the phages will be required before they can be widely used in chicken farms.

Effects of Phage Cocktail, Probiotics and Their Combinations on Growth Performance and Gut Microbiota of Broiler Chickens

“…In the current study, 1ɸ and 2ɸ groups showed significantly (P < 0.05) better FCR (1-21 d. 22-35 d, 1-35 d) than the control agrees with other studies. Previous study demonstrated that the FCR of broilers supplemented with 1 ml of 10 10 PFU/ml Salmonella typhimurium phage with the bacterial challenge was significantly better than control (Ngu et al 2022). This result was in contrast to the findings of Upadhaya et al (2021), who found that broilers supplemented with 0.5 g/kg and 1 g/kg phage cocktail (Salmonella gallinarum, Salmonella typhimurium, S. enteritidis, E. coli at 1.0 × 10 8 PFU/g each and C. perfringens at 1.0 × 10 6 PFU/g) without bacterial challenge only showed slightly (not significant) better BWG, FI and FCR than control.…”

“…and Lactobacillus spp. increased in pigs and chickens when phages were used to modulate gut microbiota (Yan et al 2012, Zhao et al 2012, Wang et al 2013, Kim et al 2014, Kim et al 2017, Ngu et al 2022. These studies indicated that phages could be utilised to modulate the gut microbiome to increase beneficial bacteria and decrease harmful bacteria.…”

Effects of Phage Cocktail, Probiotics, and Their Combination on Growth Performance and Gut Microbiota of Broiler Chickens

“…In the current study, 1ϕ and 2ϕ groups showed significantly ( p < 0.05) better FCR (1–21 days, 22–35 days, 1–35 days) than the control, in accordance with other studies. A previous study demonstrated that the FCR of broilers supplemented with 1 mL of 10 10 PFU/mL Salmonella typhimurium phage with the bacterial challenge was significantly better than that of the control [ 16 ]. This result is in contrast to the findings of Upadhaya, et al [ 36 ], who found that broilers supplemented with 0.5 g/kg and 1 g/kg phage cocktail ( S. gallinarum , S. typhimurium , S. enteritidis , and E. coli at 1.0 × 10 8 PFU/g each, and C. perfringens at 1.0 × 10 6 PFU/g) without bacterial challenge only showed slightly (not significant) better BWG, FI, and FCR than the control.…”

“…and Lactobacillus spp. increased in pigs and chickens when phages were used to modulate the gut microbiota [ 11 , 12 , 13 , 14 , 15 , 16 ]. These studies indicate that phages could be utilised to modulate the gut microbiome to increase beneficial bacteria and decrease harmful bacteria.…”