Aerosol Spray Treatment with Bacteriophages and Competitive Exclusion Reduces Salmonella Enteritidis Infection in Chickens

Abstract

A combination of three different Salmonella-specific bacteriophages (BPs) and one competitive exclusion (CE) product were used to reduce Salmonella Enteritidis (SE) colonization in experimentally infected chickens. Equal numbers of 7-day-old chickens were used in each of three groups: a CE group (treated with CE), a BP group (treated with BP), and a CE-plus-BP group (treated with both products). The CE product was administered via coarse spray at 1 day of age and the cocktail of three BPs was given via spray at 6 days of age using a multiplicity of infection of 10(3) plaque-forming units. All the experimental groups, except a healthy control group, were challenged orally with 2.95 x 10(5) colony-forming units (CFU)/ml of an SE strain at 7 days of age. Seven days postchallenge, the chickens were euthanatized for individual SE detection, quantitative bacteriology, and phage isolation from ceca and an internal organ pool. The qualitative bacteriology demonstrated that the use of the CE product diminished the incidence of SE to 75.7% and the mixture of BPs reduced it to 80%; when CE plus BP were used, the incidence dropped significantly to 38.7% (P < 0.0001), as compared with the infection control group (100%). A significant difference in the incidence was observed between the CE and the CE-plus-BP groups, and the BP and the CE-plus-BP groups (P = 0.0027 and P = 0.0010, respectively). The mean SE cecal count diminished with the use of CE plus BP (1.6 x 10(2) CFU/g, P = 0.0003) compared with the control group (1.56 x 10(5) CFU/g), the CE group (4.23 x 10(3) CFU/g), and the BP group (9.48 x 10(3) CFU/g). On the basis of the present study, it may be concluded that the use of both types of biocontrollers can be an effective method for reducing SE colonization in commercial chickens, but further basic and applied research is needed.

Bacteriophage therapy to combat bacterial infections in poultry

“…In another study, simultaneous application of three phages (MOI 103) at 10 8 PFU/ml/dose at 6 days of age (two daily doses) by aerosol spray and probiotics administered at 1 day of age by coarse spray, followed by oral inoculation with 2.95 × 10 5 CFU/ml in seven-day-old chickens, reduced Salmonella incidence and Salmonella intestinal colonization, leading to complete elimination of deaths in broiler chickens caused by infection with Salmonella Enteritidis [ 36 ]. Similar results were obtained in inhibiting horizontal infection with Salmonella following application of a bacteriophage suspension in the amount of 10 5 and 10 PFU/g as a feed additive for chickens challenged with 5 × 10 7 CFU of bacteria.…”

Evaluation of the efficacy of chitosan nanoparticles loaded ΦKAZ14 bacteriophage in the biological control of colibacillosis in chickens

“…This finding is in concordance with the reports of Borie et al. (2009) who showed the effects of a phage cocktail in reducing Salmonella enteritidis colonization in chicks, and that bacteriophage supplementation reduces salmonella colonization in broiler chickens; similarly, inclusion of bacteriophage in feed reduces cecal Escherichia coli colonization in broilers (Huff et al., 2004; Atterbury et al., 2007). It was also observed that fecal shedding of Escherichia coli (O1:K11:H7) in chicks treated with C-ΦKAZ14 NPs continued to decrease ( P ≤ 0.05) from d 7 to 21 post challenge compared with chicks treated with naked ΦKAZ14 phage and the untreated control group.…”

Framing the Future with Bacteriophages in Agriculture

“…S. enteritidis is also a prevalent foodborne pathogen, its main reservoir being the eggshell. Use of a mixture of three different Salmonella -specific phages to reduce S. enteritidis colonization in the ceca of laying hens resulted in a significant decrease in bacterial prevalence of incidence of up to 80% [ 45 ].…”