Potential Influence of Regulation of the Food Value Chain on Prevalence and Patterns of Antimicrobial Resistance: the Case of Tilapia (Oreochromis niloticus).

The current study was designed to evaluate the potential impact of the level of regulation on the prevalence and patterns of antimicrobial agent resistance in bacteria isolated from fish. The study sites included two large lakes and both semiregulated and unregulated fish value chains. A total of 328 bacterial isolates belonging to 11 genera were evaluated for antimicrobial susceptibility testing using the disk diffusion method. The bacterial species were tested against 12 different antibiotics (trimethoprim-sulfamethoxazole, tetracycline, ampicillin, cefotaxime, chloramphenicol, nalidixic acid, amoxicillin, meropenem, ciprofloxacin, nitrofurantoin, cefuroxime, and kanamycin). Data analysis was done to assess the heterogeneity in proportion of resistant bacterial species within and between the two value chains using a random-effects model proposed by DerSimonian and Laird (Control Clin Trials 7:177-188, 1986). Statistical heterogeneity within and between groups was estimated using the Cochran chi-square test and the Cochrane I2 index. The overall proportion of bacterial species resistant to antimicrobial agents in semiregulated and unregulated value chains ranged from 0.00 to 0.88 and 0.09 to 0.95, respectively. Shigella spp. had the highest proportion of bacteria that were resistant to most of the antimicrobial agents used. The bacterial species were highly resistant to ampicillin and amoxicillin, and the highest multidrug resistance capacity was observed in Shigella spp. (18.3%, n = 328), Vibrio spp. (18.3%), and Listeria monocytogenes (12.2%). We observed strong heterogeneity within and between the two value chains regarding proportion of resistant bacterial species. Sun-dried fish in both value chains had significantly high proportions of resistant bacterial species. Comparing the two value chains, the unregulated value chain had a significantly higher proportion of bacterial species that were resistant. In order to mitigate the risk of transmitting antimicrobial-resistant bacteria to consumers along the fish value chain, good manufacturing practices coupled with identification and management of possible sources of contamination are recommended for fish and potentially other foods distributed along the less regulated value chains. IMPORTANCE In order to mitigate the risk of transmitting antimicrobial-resistant bacteria to consumers along the fish value chain, good manufacturing practices coupled with identification and management of possible sources of contamination are recommended for fish and potentially other foods distributed along the less regulated value chains.

Genetically modified organisms and food security in Southern Africa: conundrum and discourse.

The importance of food security and nourishment is recognized in Southern African region and in many communities, globally. However, the attainment of food security in Southern African countries is affected by many factors, including adverse environmental conditions, pests and diseases. Scientists have been insistently looking for innovative strategies to optimize crop production and combat challenges militating against attainment of food security. In agriculture, strategies of increasing crop production include but not limited to improved crop varieties, farming practices, extension services, irrigation services, mechanization, information technology, use of fertilizers and agrochemicals. Equally important is genetic modification (GM) technology, which brings new prospects in addressing food security problems. Nonetheless, since the introduction of genetically modified crops (GMOs) three decades ago, it has been a topic of public discourse across the globe, conspicuously so in Southern African region. This is regardless of the evidence that planting GMOs positively influenced farmer's incomes, economic access to food and increased tolerance of crops to various biotic and abiotic stresses. This paper looks at the issues surrounding GMOs adoption in Southern Africa and lack thereof, the discourse, and its potential in contributing to the attainment of food security for the present as well as future generations.

Quantitative Risk Assessment of Hemolytic Uremic Syndrome Associated with Consumption of Bulk Milk Sold Directly from Producer to Consumer in South Africa.

This study was conducted to estimate the hemolytic uremic syndrome (HUS) risk associated with consumption of producer-distributor bulk milk (PDBM) contaminated with Shiga toxin-producing Escherichia coli (STEC) in South Africa. Data were obtained from recently completed studies in South Africa taking into account prior collected prevalence data of STEC in raw and pasteurized PDBM and survey information from producer-distributor outlets and households. Inputs for the models were complemented with data from published and unpublished literature. A probabilistic exposure model was developed with Monte Carlo simulation in Excel add-in software using @Risk software. Hazard characterization was based on an exponential dose-response model to calculate the probability of illness from STEC infection in individuals 5 years and younger and individuals older than 5 years. The estimated mean STEC level was 0.12 CFU/mL (95% confidence interval [CI]: 0 to 1.2; σ = 0.34) for raw PDBM and 0.08 CFU/mL (95% CI: 0 to 1; σ = 0.27) for pasteurized PDBM. A higher risk of HUS cases per year was recorded in raw than in pasteurized PDBM and also in individuals younger than 5 years of age. For every 100,000 servings consumed, the expected median numbers of HUS cases per year from raw PDBM were 52 for 5 years and younger and 3.2 for older than 5 years. The median numbers of cases per year for pasteurized PDBM were 47 for 5 years and younger and 2.9 for older than 5 years. Sensitivity analysis revealed that serving volume and time taken to sell PDBM at producer-distributor outlets were the factors with the greatest impact on probability of illness. The models developed in this study are an example of risk assessments for milk produced and marketed from similar scenarios across the globe.