The lack of hygiene and sanitation practices and insufficient infrastructure in Cambodian informal markets may increase the risk of food contamination, specifically raw vegetables, which in turn may increase the chances of contracting a foodborne disease. The aims of this study were i) to quantify the prevalence of Salmonella enterica based upon seasonal differences (rainy and dry) between surface types (food contact surface [FCS] and non-food contact surface [NFCS]) and between location of vendors within the market (inside and outside), and ii) to characterize Salmonella enterica serotypes abundance in informal markets in Cambodia. A total of 310 samples were screened for Salmonella enterica prevalence following the U.S. Department of Agriculture guidelines and confirmed by PCR. Whole Genome Sequencing was performed and the serotype for each isolate was determined in-silico using SeqSero 1.0 on draft genomes. A total of 78 samples were confirmed positive for Salmonella enterica . During the dry season, Salmonella enterica was more prevalent on FCS compared to NFCS (estimated probability of detection [confidence interval]: 0.41 [0.25,0.59] and 0.17 [0.08, 0.32], respectively; P=0.002), though no differences were apparent during the rainy season. Further, there was no evidence of any differences in Salmonella enterica prevalence based on location within the market (P=0.61). Sixteen Salmonella enterica serotypes were detected across multiple surfaces. The most common serotypes were Rissen (n=18), Hvittingfoss (n=11), Corvallis (n=10), Krefeld (n=8), Weltevreden (n=6), and Altona (n=6). The availability of accurate data on the prevalence of Salmonella enterica in informal markets is crucial for the development of effective surveillance and implementation of suitable intervention strategies at the domestic level, thus preventing future foodborne illness.
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.
Vegetables in Cambodia are commonly sold in informal markets lacking food safety standards and controls. Currently, data on microbial contamination of vegetables in Cambodian informal markets are limited. The purpose of this study was to investigate Salmonella enterica and indicator organisms (generic Escherichia coli and coliforms) on the surface of fresh vegetables sold in informal markets in Cambodia. A sample of loose-leaf lettuce, tomatoes, and cucumbers were collected from 104 vendors at four informal markets in Battambang and Siem Reap provinces during rainy and dry seasons. Detection methods for Salmonella enterica were adapted from the Food and Drug Administration’s Bacteriological Analytical Manual (FDA BAM). Quantification of coliforms and generic E. coli populations was conducted by plating onto E. coli/Coliform count plates. Salmonella enterica was most prevalent on lettuce during the dry season (56.5%, 95% CI [41.0, 70.8]) compared to the rainy season (15.4 95% CI [7.5, 29.1]), whereas no significant seasonal differences were apparent for tomatoes and cucumbers. Regardless of season, levels of Salmonella enterica were highest on lettuce (5.7 log CFU/g, 95% CI [5.5, 5.9]), relative to cucumbers (4.2 log CFU/g, 95% CI [3.8, 4.6]) and tomatoes (4.3 log CFU/g, 95% CI [4.1, 4.6]). For generic E. coli, prevalence was higher during the rainy season (34.0%, 95% CI [25.4, 43.8]) as compared to the dry season (9.1%, 95% CI [4.9, 16.5]), with the highest prevalence estimated on lettuce. Similarly, the level of coliforms on lettuce and tomatoes was greater during the rainy season (6.3 and 5.3 log CFU/g, 95% CI [5.7, 6.8] and [4.7, 5.8], respectively), relative to the dry season (5.2 and 3.9 log CFU/g, 95% CI [4.7, 5.7] and [3.4, 4.4], respectively). In summary, these results indicate seasonal patterns for microbial prevalence in lettuce, and an overall high level of bacterial contamination on raw vegetables sold in Cambodian informal markets.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.