A new Epseptimavirus bacteriophage vB_SalS-SIY1lw as a potential antimicrobial alternative to multidrug-resistant Salmonella Infantis
Why Salmonella Infantis Is the Next Big Threat on the Broiler Farm
Recent genomic surveys show that Salmonella Infantis has become the dominant multidrug‑resistant (MDR) serovar in U.S. Poultry. A single clonal lineage carrying the pESI plasmid now accounts for the surge in raw chicken and turkey products (McMillan et al., 2022).
Rising MDR Rates in Broilers and Swine
A 2025 study from China reported that 70.67 % of broiler isolates and 80.58 % of swine isolates were MDR (Epidemic trend of Salmonella from swines and broilers in China).
pESI Plasmid: The MDR Engine
The pESI plasmid not only spreads extended‑spectrum cephalosporin resistance in S. Infantis but also appears in other serovars such as Senftenberg and Alachua (Li et al., 2024).
One‑Health Perspective: From Farm to Fork
Researchers emphasize that the rise of MDR S. Infantis is a classic One‑Health issue, linking animal production, human health, and the environment (Mattock et al., 2024).
Holistic Control Strategies in Europe
European broiler sectors are adopting integrated measures—vaccination, biosecurity, and targeted antimicrobial stewardship—to curb S. Infantis spread (Montoro‑Dasi et al., 2023).
New Variants Without Somatic Antigen
A 2023 report described a novel S. Infantis variant lacking the usual somatic antigen, complicating serological detection (Alessiani et al., 2023).
Bacteriophages: The Rising Counter‑measure
Phage therapy is moving from “foe to friend.” Studies show that phage‑driven cleaning and disinfection can dramatically lower S. Infantis loads on broiler farms (Sevilla‑Navarro et al., 2024).
Targeted Phage Cocktails
A multireceptor phage cocktail was engineered to bypass bacterial resistance mechanisms, achieving > 4‑log reductions of S. enterica in lab trials (Martinez‑Soto et al., 2024).
Phage Genome Insights Fuel Design
High‑resolution structural work on T5‑like phages (e.g., DT57C) reveals complex tail‑fiber architectures that dictate host range (Ayala et al., 2023), while deep‑learning tools like DeepPL predict phage life cycles with > 95 % accuracy (Zhang et al., 2024).
Future Trends to Watch
- Genome‑guided surveillance: Real‑time sequencing of farm isolates will enable early detection of pESI‑carrying strains.
- Phage‑based biosecurity: Routine application of phage cocktails on equipment and litter could become a standard disinfection step.
- Regulatory harmonization: International guidelines are likely to converge on phage safety assessments, following frameworks outlined by the FDA and EFSA.
- AI‑driven resistance prediction: Tools like DeepPL will be paired with ResFinder 4.0 to forecast emerging resistance patterns before they hit the market (Bortolaia et al., 2020).
Frequently Asked Questions
- What makes the pESI plasmid so dangerous?
- It carries multiple resistance genes, including those for extended‑spectrum β‑lactams, and can spread rapidly between serovars.
- Can phage therapy replace antibiotics on farms?
- Phages are not a silver bullet yet, but they can significantly reduce bacterial loads when used alongside good hygiene and targeted antimicrobial use.
- How do I know if a phage product is safe?
- Look for genomes vetted with PhageTerm and classified by VICTOR, and ensure the manufacturer follows the latest One‑Health guidelines.
- Are there any commercial phage products for Salmonella?
- Yes, several companies have launched phage‑based sprays for poultry environments; they are typically derived from isolates like those reported in Thailand (Pelyuntha et al., 2021).
Take Action
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