Prevalence of colistin-resistant Escherichia coli in foods and food-producing animals through the food chain: A worldwide systematic review and meta-analysis.

The purpose of this systematic review and meta-analysis was to summarize the available scientific evidence on the prevalence of colistin-resistant Escherichia coli strains isolated from foods and food-producing animals, the mobile colistin-resistant genes involved, and the impact of the associated variables. A systematic review was carried out in databases according to selection criteria and search strategies established a priori. Random-effect meta-analysis models were fitted to estimate the prevalence of colistin-resistant Escherichia coli and to identify the factors associated with the outcome. In general, 4.79% (95% CI: 3.98%-5.76%) of the food and food-producing animal samples harbored colistin-resistant Escherichia coli (total number of colistin-resistant Escherichia coli/total number of samples), while 5.70% (95% confidence interval: 4.97%-6.52%) of the E. coli strains isolated from food and food-producing animal samples harbored colistin resistance (total number of colistin-resistant Escherichia coli/total number of Escherichia coli isolated samples). The prevalence of colistin-resistant Escherichia coli increased over time (P < 0.001). On the other hand, 65.30% (95% confidence interval: 57.77%-72.14%) of colistin resistance was mediated by the mobile colistin resistance-1 gene. The mobile colistin resistance-1 gene prevalence did not show increases over time (P = 0.640). According to the findings, other allelic variants (mobile colistin resistance 2-10 genes) seem to have less impact on prevalence. A higher prevalence of colistin resistance was estimated in developing countries (P < 0.001), especially in samples (feces and intestinal content, meat, and viscera) derived from poultry and pigs (P < 0.001). The mobile colistin resistance-1 gene showed a global distribution with a high prevalence in most of the regions analyzed (>50%). The prevalence of colistin-resistant Escherichia coli and the mobile colistin resistance-1 gene has a strong impact on the entire food chain. The high prevalence estimated in the retail market represents a potential risk for consumers' health. There is an urgent need to implement based-evidence risk management measures under the "One Health" approach to guarantee public health, food safety, and a sustainable future.

Macroencapsulation of Limosilactobacillus reuteri DSPV002C as nutritional supplement for piglets: Storage stability and survival in gastrointestinal conditions.

The aim of this study was to evaluate the protective effect of the encapsulation of Limosilactobacillus reuteri DSPV002C in macrocapsules made from industrial materials during production, storage and under simulated gastrointestinal conditions in vitro and in vivo. The production of macrocapsules involved the evaluation of different wall materials (matrix), namely, gelatin and pregelatinized starch, different inoculums, matrix ratios, and diverse cryoprotectants (whey permeate and maltodextrin). The different macrocapsules were arranged in molds of similar size to pig pelleted food and lyophilized. Then, the viability of the macrocapsules was assessed over time during storage at different temperatures (freezing, refrigeration and room temperature) and atmospheres (vacuum and non-vaccum). The macrocapsules with 10% w/v gelatin+5% w/v pregelatinized starch, permeated (10%, w/v), with a 9:1 inoculum:matrix ratio (GS7.5P9), stored under freezing conditions and vacuum, exhibited the highest viability of L. reuteri DSPV002C (9.3 log CFU/cap until 210 d). Under simulated gastrointestinal conditions, the encapsulated inoculum showed less viability loss (0.58±0.09 log CFU/ml, 26.53%), compared to the free culture (1.56±0.16 log CFU/ml, 2.85%). Finally, by administering GS7.5P9 to pigs, the tolerance of the bacteria to the gastrointestinal environment was verified, with viable counts equal to or greater than 3.72 log CFU/g of fecal matter throughout the trial. In this study, a high-density carrier probiotic macrocapsule of L. reuteri DSPV002C was obtained, which displayed a long shelf life, a suitable shape to be included in pig feed and an adequate survival of viable cells at the site of action.

Effects of lactic acid bacteria and coagulase-negative staphylococci on dry-fermented sausage quality and safety: Systematic review and meta-analysis.

The meta-analysis aim was to confirm and quantifying the influence of starter cultures on microbiological and physical-chemical parameters of dry-fermented sausages at the end fermentation stage. The literature search yielded 1194 citations, and 77 studies with 178 experiments were eligible and included in the meta-analysis, a random-effects model was used to estimate the pooled weighted mean difference (MD) with 95% confidence interval (CI).The use of starter culture in dry-fermented sausages significantly reduced pH (MD: -0.364; CI: -0.414; -0.319), moisture (MD: -1.443; CI: -1.931; -0.955), aw (MD: -0.011; CI: -0.017; -0.006), Enterobacteriaceae count (MD: -1.119; CI: -1.293; -0.945), yeasts and molds count (MD: -0.351; CI: -0.691; -0.084), and increased color component a* (MD: 0.859; CI: 0.266;1.452), color component L* (MD: 1.288; CI: 0.433; 2.143), LAB count (MD: 0.981; CI: 0.696;1.267), Staphylococci count (MD: 0.484; CI: 0.293; 0.675) and TVC (MD: 0.529; CI: 0.098; 0.959). The results of the sub-analysis suggest that the addition of LAB and LAB/CNS inocula have a greater effect on the physico-chemical and microbiological parameters studied in this work. In the meta-regression analysis, a positive linear relationship was found in starter culture sausages in comparison with control batch between LAB count and the dose of starter culture added, and in the pH and Enterobacteriaceae count with the passage of fermentation days. In contrast, a negative linear relationship was found between redness and increased casing diameter of the sausages. Therefore, our work shows impact that addition of starter cultures has on safety and quality of dry-fermented sausages.

Biological Functions of Exopolysaccharides from Lactic Acid Bacteria and Their Potential Benefits for Humans and Farmed Animals.

Lactic acid bacteria (LAB) synthesize exopolysaccharides (EPS), which are structurally diverse biopolymers with a broad range of technological properties and bioactivities. There is scientific evidence that these polymers have health-promoting properties. Most commercialized probiotic microorganisms for consumption by humans and farmed animals are LAB and some of them are EPS-producers indicating that some of their beneficial properties could be due to these polymers. Probiotic LAB are currently used to improve human health and for the prevention and treatment of specific pathologic conditions. They are also used in food-producing animal husbandry, mainly due to their abilities to promote growth and inhibit pathogens via different mechanisms, among which the production of EPS could be involved. Thus, the aim of this review is to discuss the current knowledge of the characteristics, usage and biological role of EPS from LAB, as well as their postbiotic action in humans and animals, and to predict the future contribution that they could have on the diet of food animals to improve productivity, animal health status and impact on public health.

Impact of farm-level strategies against thermotolerant Campylobacter in broiler chickens, using a quantitative risk assessment model and meta-analysis.

The aim of this study was to evaluate the effect of control strategies (probiotic supplementation and vaccination) at farm on thermotolerant Campylobacter infection due to the consumption of salad cross-contaminated from broiler meat. The broiler food chain was modelled considering the most common practices applied in Argentina (baseline model) and their effect on the prevalence and counts of Campylobacter. Probiotic supplementation and vaccination against Campylobacter spp. were included in different models to evaluate their effectiveness. The parameter distributions of each intervention were obtained based on a systematic review and meta-analysis previously described. The control measures applied at farms were evaluated considering their effectiveness in reducing both the prevalence and the count of thermotolerant Campylobacter in comparison with the baseline model estimation and expressed as relative change in campylobacteriosis risk. Additionally, the identification of the most important input parameters for the model was performed by sensitivity analysis. The model estimated a risk of campylobacteriosis per consumed serving of salad contaminated with poultry meat of 4.99 x 10-3 (95% CI: 6.12 x 10-6 -1.13 x 10-2 ), corresponding to an annual incidence risk estimated of 1,876,009 persons. Scenario analysis indicated that the application of vaccines against Campylobacter (probability of campylobacteriosis = 9.55 x 10-4 ; 95% CI: 5.31 x 10-4 -1.29 x 10-3 ) and the supplementation of broilers with probiotics (probability of campylobacteriosis = 1.32 x 10-3 ; 8.55 x 10-4 -1.69 x 10-3 ) can offer a modest reduction in risk estimates. The intervention efficacy was 80.86% and 73.54% for vaccination and probiotic supplementation, respectively. On-farm interventions were effective to mitigate the risk of campylobacteriosis.

Capacidad de Lactiplantibacillus plantarum LP5 para inhibir biopelículas de Campylobacter coli / Ability of Lactiplantibacillus plantarum LP5 to inhibit biofilms of Campylobacter coli

Resumen El objetivo de este estudio fue evaluar la capacidad inhibitoria de Lactiplantibacillus plantarum LP5 frente a Campylobacter coli en ensayos de formación de biopelículas in vitro y exclusión competitiva. La formación de biopelículas por C. coli NCTC11366, C. coli DSPV458, C. coli DSPV541 y C. coli DSPV570 fue evaluada mediante medición de DO. La capacidad inhibitoria de L. plantarum LP5 frente a C. coli fue evaluada sobre discos de vidrio, nailon y aluminio. Sobre una biopelícula de L. plantarum se adicionó C. coli para cuantificar el efecto inhibidor de L. plantarum LP5 sobre el patógeno. Las cuatro cepas de C. coli fueron clasificadas como moderadas formadoras de biopelículas. El ensayo de exclusión competitiva mostró que la formación de biopelículas de las cepas de C. coli en todos los materiales fue significativamente mayor que la formación de biopelículas de cada patógeno en presencia de biopelículas de L. plantarum LP5. Si bien es necesario realizar más pruebas para confirmar la capacidad de supervivencia de C. coli en ambientes hostiles hasta llegar al huésped, este estudio permitiría avanzar en el esclarecimiento de su comportamiento mediante la formación de biopelículas.

Abstract The objective of this study was to evaluate the inhibitory capacity of Lactiplantibacillus plantarum LP5 against Campylobacter coli in in vitro biofilm formation and competitive exclusion assays. Biofilm formation by C. coli NCTC11366, C. coli DSPV458, C. coli DSPV541 and C. coli DSPV570 was evaluated by OD measurement. The inhibitory capacity of L. plantarum LP5 against C. coli was evaluated on glass, nylon and aluminium discs, added with L. plantarum and incubated at 37°C for 72 h. C. coli was added to each washed well. The plates were incubated at 42°C for 72 h in microaerophilic conditions and the biofilms were detached for quantification. The four strains of C. coli were classified as moderate biofilm former. The competitive exclusion test showed that the biofilm formation of the C. coli strains in all materials was significantly higher than the biofilm formation of each pathogen in the presence of L. plantarum LP5 biofilms. Although it is necessary to carry out more tests to confirm the ability of C. coli to survive in hostile environments until reaching the host, this study would allow progress in the elucidation of its behaviour through the formation of biofilms.