Efficacy of phage therapy in pigs: systematic review and meta-analysis

Abstract

Limits on the use and efficacy of various antibiotics coupled with negative consumer perception of the practice have together spurred substantial research into compounds that could reduce the use antibiotics to control bacterial diseases in pigs. Bacteriophages are often among such potential compounds, and various groups have examined the efficacy of bacteriophages or bacteriophage products in limiting transmission or colonization of targeted bacteria. The study presented here provides a systematic review of such studies followed by a meta-analysis of aggregated data produced by each study. The data set was limited to inputs (n = 19; 576 total observations) from studies where: 1) live pigs were inoculated with a known quantity of challenge bacteria; 2) challenged animals were treated with a known quantity of phages; 3) concentrations of the challenge bacteria were measured in different tissues/fluids following phage treatment; and 4) SD (or SE to allow calculation of SD) was reported. Concentrations of challenge bacteria were significantly lower in phage-treated pigs versus challenged but untreated pigs (P < 0.0001; effect size = −1.06 1log10 colony-forming units [CFU]/g). The effect size of phage treatment was significantly greater (P < 0.05) in samples collected 48 to 96 h following phage treatment versus those collected ≤ 24 h following phage treatment. Likewise, effect size of phage treatment was significantly greater in piglets versus market-weight pigs. Across observations, phage treatment effect sizes were greatest (P < 0.01) in fecal samples versus ileal or cecal samples. Taken together, these data indicate that phage treatment can significantly reduce the concentrations of targeted bacteria in pigs; scenarios exist, however, where phage treatment could predictably be more or less effective.

One Health challenges for pig reproduction

“…Innovative solutions are also needed to solve infection and resistance related problems in the future, as antibiotic use needs to be reduced and critically important antibiotic compounds need to be reserved for human use. Suggested strategies to reduce antimicrobial use include probiotics (Nordeste et al, 2017), bacteriophages targeted at specific microbes (Desiree et al, 2021), and various compounds with antimicrobial effects, e.g., zinc, copper, or antimicrobial peptides (Monger et al, 2021). The use of antibiotics in reproduction could, for example, also be limited by using antibiotic‐free semen (Jäkel et al, 2021), antimicrobially active semen extenders (Luther et al, 2021), or colloid centrifugation to remove bacteria from insemination doses (Morrell et al, 2019), but more research is needed to provide economically feasible and practical solutions.…”

Bacteriophages and Food Production: Biocontrol and Bio-Preservation Options for Food Safety

“…E. coli induced diarrhoea in pigs’ results in high mortality and morbidity, decreased growth rate, and significant economic losses. Studies have shown a reduced presence of intestinal E. coli in phage treated pigs compared to untreated control groups [ 47 ]. The Campylobacter phage CP220 demonstrated an ability to reduce C. jejuni in chickens by ca.…”

Invited review: strategic adoption of antibiotic-free pork production: the importance of a holistic approach

“…Suffice it to say that much more research is required before phages can achieve their full potential as a tool for nutritionists and veterinarians to utilize in the pork industry in support of ABF production. Nonetheless, it is an area of great interest, due to the potential phages could bring to pork production if these practical and technical issues can be adequate addressed ( Desiree et al, 2021 ).…”