Poultry meat products can become contaminated with Salmonella, a type of bacteria that can cause serious illness and lead to economic losses from product recalls.
It is important to control Salmonella contamination in poultry at all stages of production. In a study, three Salmonella-specific viruses called bacteriophages (phages) were tested for their ability to kill Salmonella.
These phages, called vB_SenS_KP001, vB_SenS_KP005, and vB_SenS_WP110, were recovered from a poultry farm and wastewater treatment plants, and were found to be effective at killing over 56 different types of Salmonella.
A combination of these three phages, called a cocktail, was able to significantly reduce the presence of two types of Salmonella, S. Enteritidis and S. Typhimurium, in a laboratory setting.
The phage cocktail was also found to be safe and did not cause any harm to human cells in laboratory tests. When the phage cocktail was given to broiler chickens, it significantly reduced the presence of naturally occurring Salmonella in the chickens’ gastrointestinal tracts.
These results suggest that the phage cocktail may be a useful tool for controlling Salmonella in poultry production to improve food safety.
The authors Wattana Pelyuntha, Ananya Yafa, Ruttayaporn Ngasaman, Mingkwan Yingkajorn, Kridda Chukiatsiri, Nidanut Champoochana, and Kitiya Vongkamjan published their findings in the article ‘Oral Administration of a Phage Cocktail to Reduce Salmonella Colonization in Broiler Gastrointestinal Tract-A Pilot Study‘, dated 9 November 2022.
Key topics include:
- Salmonella contamination in poultry products can lead to serious illness and economic losses
- It is important to control Salmonella contamination in poultry throughout the production process
- Bacteriophages (phages) are viruses that specifically target bacteria and can be used to control Salmonella
- In this study, three Salmonella-specific phages were effective at killing over 56 types of Salmonella
- A cocktail of these three phages was able to significantly reduce the presence of S. Enteritidis and S. Tphimurium in a laboratory setting
- The phage cocktail was also found to be safe and did not cause harm to human cells in laboratory tests
- When the phage cocktail was given to broiler chickens, it significantly reduced the presence of naturally occurring Salmonella in their gastrointestinal tracts
Abstract
Salmonella contamination in poultry meat products can lead to serious foodborne illness and economic loss from product recalls. It is crucial to control Salmonella contamination in poultry from farm to fork.
Bacteriophages (phages) are viruses of bacteria that offer several advantages, especially their specificity to target bacteria. In our study, three Salmonella phages (vB_SenS_KP001, vB_SenS_KP005, and vB_SenS_WP110) recovered from a broiler farm and wastewater treatment stations showed high lysis ability ranging from 85.7 to 96.4% on over 56 serovars of Salmonella derived from several sources, including livestock and a broiler farm environment.
A three-phage cocktail reduced S. Enteritidis and S. Typhimurium, in vitro by 3.9 ± 0.0 and 3.9 ± 0.2 log units at a multiplicity of infection (MOI) of 103 and 3.8 ± 0.4 and 4.1 ± 0.2 log units at MOI of 104 after 6 h post-phage treatment.
A developed phage cocktail did not cause phage resistance in Salmonella during phage treatments for three passages.
Phages could survive under simulated chicken gastrointestinal conditions in the presence of gastric acid for 2 h (100.0 ± 0.0% survivability), bile salt for 1 h (98.1 ± 1.0% survivability), and intestinal fluid for 4 h (100 ± 0.0% survivability).
Each phage was in the phage cocktail at a concentration of up to 9.0 log PFU/mL. These did not cause any cytotoxicity to human fibroblast cells or Caco-2 cells as indicated by the percent of cell viability, which remained nearly 100% as compared with the control during 72 h of co-culture.
The phage cocktail was given to broilers raised in commercial conditions at a 9 log PFU/dose for five doses, while naturally occurring Salmonella cells colonized in the gastrointestinal tract of broilers were significantly reduced as suggested by a considerably lower Salmonella prevalence from over 70 to 0% prevalence after four days of phage treatment.
Our findings suggest that a phage cocktail is an effective biocontrol agent to reduce Salmonella present in the guts of broilers, which can be applied to improve food safety in broiler production.
Keywords: Salmonella; biocontrol; broiler; food production animals; phage treatment; salmonellosis.
Copyright: the authors.
Antibiofilm activity of a lytic Salmonella phage on different Salmonella enterica serovars isolated from broiler farms
