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.

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IntroductionSeveral Cambodian initiatives seek to improve nutritional outcomes via increased production and consumption of nutrient-dense foods, including vegetables. However, food safety gaps in informal markets, where most vegetables are purchased, allow for the transmission of foodborne pathogens and threaten the positive nutritional outcomes associated with vegetable consumption.MethodsThis study describes a tool used to measure perceptions of Cambodians involved with informal vegetable markets regarding their capabilities, opportunities, and motivations to implement food safety practices. The quantitative tool could also be used to assess capability, opportunity, and motivation to adopt a behavior in a wide range of development contexts. To these ends, a questionnaire assessing these perceptions was developed using the Capability, Opportunity, Motivation-Behavior (COM-B) model of behavior and the Theoretical Domains Framework (TDF).ResultsThe questionnaire was piloted with vegetable vendors in Phnom Penh (N = 55), revised, and subsequently implemented in the provinces of Battambang and Siem Reap with vegetable producers, distributors, and vendors (N = 181). Confirmatory factor analysis resulted in a nine-factor model corresponding to TDF constructs with a comparative fit index of 0.91, a Tucker-Lewis index of 0.89, and a root mean square error of ~0.05. Further analysis indicated that vegetable vendors and distributors typically had significantly higher (p < 0.05) levels of perceived motivation and capability to implement the target food safety practice (washing surfaces that come in contact with vegetables with soap and water every day) compared to their perceived opportunity to do so. Among farmers, however, levels of perceived motivation were significantly higher (p < 0.05) than levels of perceived opportunity and capability. In addition, vendors in Battambang had significantly higher (p < 0.05) levels of perceived capability, opportunity, and motivation to implement the target food safety practice in comparison to farmers in either province. Vendors in Battambang had significantly higher (p < 0.05) levels of perceived opportunity and motivation than vendors in Siem Reap.ConclusionsThese data suggest that efforts to bolster vegetable vendors' and distributors' perceived opportunity and vegetable farmers' perceived opportunity and capability to implement food safety practices could increase the likelihood of adoption of the target food safety practice.