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.

Meta-analysis of the prevalence of norovirus and hepatitis a virus in berries.

Norovirus (NoV) and hepatitis A virus (HAV) stand as the predominant agents associated with viral foodborne infections. Outbreaks have been documented to be caused by various types of food items, including fresh and/or frozen berries. Comprehensive data concerning crucial viral pathogens in berries remain limited and are not currently available in aggregate form. Consequently, the present study aimed to compile the existing information regarding the prevalence of NoV and HAV in this matrix. Records of foodborne viruses were systematically extracted from database repositories up to December 2022, adhering to PRISMA standards and were subjected to a multilevel random effect meta-analysis model to determine the mean occurrence rate of NoV and HAV. A high heterogeneity across studies was observed (I2 = 82 %), reflecting variations in the prevalence of sampling locations, years, berry types, and sample conditions, among other potential contributing factors. The prevalence of NoV and HAV in berries was calculated at 2.12 % (95 % CI 1.74-2.59 %), and no statistically differences were observed among the viral types or genogroup categories. However, it is important to clarify that this estimate should be taken with caution given the high heterogeneity. There was no discernible correlation between viral prevalence and any particular berry type. However, there was a temporal correlation observed with the year of sampling, revealing a significantly decreasing trend throughout the study period. A significant influence of the sample condition (fresh or frozen) was observed in relation to the prevalence of NoV GII and HAV. Overall higher viral prevalences were identified in berries originating from African countries as compared to those sourced from other continents. It was also noted that the prevalence of NoV GI was significantly higher in samples collected directly from farms compared to those obtained from retailers. The outcomes of this comprehensive meta-analysis propose that while viral contamination of berries is diminishing in more recent times, the prevalence remains substantial in certain African countries, having a significant risk for foodborne infections. It is imperative to implement intervention strategies in these regions to enhance product safety.

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.

Stochastic modelling to predict a priori the potential outcomes of different control schemes against the cattle tick Rhipicephalus microplus.

Stochastic models are valuable tools to describe and analyze tick population dynamic in a given area, and to evaluate different control schemes. The objective of this study was to provide a tool to predict a priori how a control scheme could affect the abundance of Rhipicephalus microplus in an area highly favourable for its development, through the building of a stochastic model of the population dynamic of this tick. The dynamic was stochastically modelled using field data of the parasitic and non-parasitic phases of R. microplus. The host susceptibility to tick infestations was also considered by including representative values of natural resistance of three different breeds (Bos indicus, B. taurus and B. indicus x B. taurus). Two different control schemes (strategic and threshold methods) using three annual applications of synthetic acaricides in different moments were evaluated. Furthermore, we have evaluated the impact of different moments of pasture spelling as a tool for tick control on the dynamic of the non-parasitic phases of R. microplus. The results showed that the model appropriately fits to field data and can simulate the annual variability in female ticks count in animals from different ecological characteristics. The model has also captured the variability that host susceptibility has on tick abundance. This fact was expressed in the different levels of tick abundance obtained for the three breeds of bovines. According to the model, strategic control applications of chemical acaricides have more efficacy than the threshold control method. The model indicates that a pasture spelling started in early or mid-summer generates a higher reduction in the number of available eggs in pastures. Analysis of the results allows to conclude that the model developed in this study was useful to predict a priori the performance of different control methods based on the strategic application of chemical acaricides or by applying pasture spelling.

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.

Meta-analysis of the prevalence of the main human pathogens in vegetables, with emphasis on lettuce.

This meta-analysis aims to summarize the available information on the prevalence of the main human pathogenic microorganisms in vegetables, with emphasis on lettuce (Lactuca sativa). The database searches included scientific papers from 1980 to 2019, without language restrictions. Inclusion criteria were prevalence or incidence studies published in peer-reviewed journals reporting the total number of vegetable samples studied and the number of samples positive for the presence of the studied pathogens. The target pathogens were grouped into the following categories: bacteria, parasites and viruses. Results of different vegetable types, years of sampling, analyzed regions or species of microorganisms reported in the same article were considered as different studies. Therefore, each scientific article may contain several studies. Multilevel random-effect meta-analysis models were fitted to estimate the mean occurrence rate of pathogenic microorganisms and to compare them with different factors potentially associated with the outcome. Overall, the prevalence of bacterial, parasitic and viral pathogens in vegetables was relatively low. The mean prevalence of bacterial hazards was < 0.023, with the exception of S. aureus, whose prevalence was estimated at 0.096. The mean occurrence rates of parasites and viruses were 0.067 (95 % CI: 0.056-0.080) and 0.079 (95 % CI: 0.054-0.113), respectively. The prevalence of pathogenic E. coli and parasites increased as the year of publication of the scientific articles progressed, whereas the prevalence of the other bacterial pathogens and enteric viruses was steady. The types of vegetables evaluated did not affect pathogen prevalence. The prevalence of pathogenic microorganisms differed according to the continent of origin, except for E. coli O157:H7 and parasites. The prevalence of pathogens in vegetables is of public health importance, especially in vegetable types that are eaten raw, without thermal treatment to inactivate pathogens. This meta-analysis results show the need to apply proper sanitation methods to treat raw vegetables in order to avoid foodborne infections.

Leptospiral infection: a serosurvey in urban and rural communities in Olavarría county, Argentina.

INTRODUCTION: Leptospirosis is a neglected zoonotic disease, affecting mainly poor and vulnerable populations. METHODOLOGY: A cross sectional-study was carried out in 557 subjects from Olavarría county (Argentina) to estimate the seroprevalence of leptospirosis and the factors associated with seropositivity. A survey was carried out to obtain clinical and epidemiological data. Serum was tested for anti-leptospiral antibodies by Microscopic Agglutination Test (MAT). Chi-square or Fisher Exact tests were used to assess association between the MAT results and the exploratory variables. For the variables statistically associated, odds ratios (ORs) and 95% confidence intervals (95% CI) were calculated. Individuals from Olavarría city were georeferenced to describe the spatial distribution and to detect clusters of seropositivity for leptospiral antibodies. RESULTS: The overall prevalence of leptospirosis infection was 7.00%, higher in rural (19.66%) than in urban populations (3.64%) (p < 0.001). Sejroe was the most predominant serogroup in rural communities while Icterohaemorrhagiae was the most prevalent in urban populations. The factors associated with Leptospira infection were the presence of rodents inside households (OR = 3.9) in rural populations, while contact with cats (OR = 4.97) and male gender (OR = 7.75) represented higher risk of infection for the urban ones. Cases with positive serology have been found near Tapalqué stream or in the peripheral areas of Olavarría city. CONCLUSIONS: The results from data obtained during the study period were similar to other reports and demonstrate the importance of continuous epidemiological surveillance system and specific community educational campaigns to prevent the leptospirosis infection in Olavarría county and other communities with similar characteristics especially in rural areas.

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.

Awareness of zoonoses in freshmen entering the veterinary school* / Conhecimento sobre zoonoses em um grupo de estudantes recém-matriculados no curso de medicina veterinária

In veterinary practice, the risk of zoonotic infections starts in College, when students are exposed to animals, and laboratory assignments. The objective of this study was to estimate awareness of zoonoses in a cohort of freshmen at the Facultad de Ciencias Veterinarias, Universidad Nacional del Litoral, Santa Fe (Argentina). A cross sectional study was conducted using a structured questionnaire in all students attending an introductory course (N= 179) on April, 2012. Data analysis included descriptive statistics and χ2. Zoonoses most frequently mentioned by students were rabies, scabies, tuberculosis and leptospirosis. Rural residence was associated with the recognition of ringworm (P= 0.0136), tuberculosis (P= 0.0302), leptospirosis (P= 0.0205) and hydatidosis (P= 0.0167) as zoonoses. Males showed higher awareness of trichinosis (P= 0.0025), tuberculosis (P= 0.0286), anthrax (P= 0.0035), and brucellosis (P= 0.0038) than females. Awareness of susceptible species and means of transmission varied among all zoonoses. These results reinforce the need for early exposure of veterinary students to occupational health and biosafety practices.

No exercício da medicina veterinária, o risco de contrair zoonoses está presente desde o período estudantil, proporcionado pela exposição a animais e também a atividades laboratoriais. O objetivo deste estudo foi estimar o conhecimento sobre zoonoses em um grupo de estudantes recém-matriculados no curso de medicina veterinária da Universidade Nacional do Litoral, Santa Fe (Argentina). Realizou-se um estudo transversal utilizando-se um questionário pré-elaborado para todos os alunos recémmatriculados (N=179). A análise dos dados incluiu estatísticas descritivas e teste Qui-quadrado (X2 ). As zoonoses mais citadas pelos alunos foram raiva, sarna, tuberculose e leptospirose. A variável "residir em áreas rurais" esteve associada ao reconhecimento de dermatofitoses (P=0,0136), tuberculose (P=0,03020), leptospirose (P=0,0205) e hidatidose (P=0,0167), como zoonoses. Da mesma forma, a variável "sexo masculino" esteve associada à identificação de triquinelose (P=0,0025), tuberculose (P=0,0286), carbúnculo hemático (P=0,0035) e brucelose (P=0,0038). O conhecimento sobre as formas de transmissão e as espécies acometidas variou de acordo com cada zoonose em particular. Esses resultados reforçam a necessidade de um contato mais precoce de estudantes de medicina veterinária com temas relacionados com a saúde ocupacional e práticas de biossegurança. Palavras chave: higiene, estudantes de veterinária, segurança do trabalho, infecções zoonóticas.

Factors associated with sporadic verotoxigenic Escherichia coli infection in children with diarrhea from the Central Eastern Area of Argentina.

Verotoxigenic Escherichia coli (VTEC) are one of the most important emerging foodborne pathogens and the principal cause of hemolytic uremic syndrome (HUS). This entity has been recognized worldwide as a priority issue in the field of zoonoses and public health, and Argentina is the country with the highest incidence of HUS in children less than 5 years of age.The lack of specific treatment, combined with the high morbidity rate of VTEC infection, makes prevention the main tool for reducing the incidence of HUS. The current work aimed at assessing the factors associated with sporadic VTEC infection in children with acute diarrhea from the Central Eastern area of Argentina where the incidence rate of HUS in children under 5 is the highest worldwide. A univariate analysis was performed to identify potential factors associated with VTEC infection by calculating odds ratios (OR) with 95% confidence intervals (CI). Then, a multivariate logistic regression model was performed. Interaction and association between significant factors were checked. "Recent consumption of food prepared outside home" (OR: 2.4, 95% CI 1.05-5.7) and "recent vegetables consumption" (OR=0.4; 0.2-0.8) were identified as independent factors associated with VTEC infection. We believe that the data obtained from this study further the current knowledge about the epidemiology of VTEC infection in Argentina and could be considered when planning strategies for the prevention of the disease.