Murine colonization model by Campylobacter coli DSPV458.

AIMS: To generate a murine experimental model of colonization by Campylobacter coli DSPV458. METHODS AND RESULTS: Twelve adult Balb/cCmedc female mice were housed in a treated group (T-G) and a control group (C-G) for 4 weeks. Both experimental groups received antibiotics for 5 days during the first week. The T-G was administered with 6.68log10 CFU of C. coli DSPV458 by oesophageal gavage. Necropsies were performed weekly to evaluate translocation and intestinal colonization in the spleen and liver and in the ileum and cecum respectively. Samples were cultured to quantify intestinal microbiota members. Faeces were cultured weekly for a C. coli DSPV458 count. Campylobacter coli DSPV458 was isolated from all the inoculated mice. The recovered level of C. coli DSPV458 was, on average, 6.9 log10 CFUg-1 , 8.0 log10 CFUg-1 and 1.6 log10 CFUg-1 in faeces, cecum and ileum respectively. Colonization by C. coli DSPV458 does not alter the normal clinical and physiological status. CONCLUSIONS: Campylobacter coli DSPV458 does not have an invasive capacity, and the model is suitable for evaluating strategies to reduce intestinal loads. SIGNIFICANCE AND IMPACT OF STUDY: Farm animals have an important impact on thermotolerant Campylobacter transmission to humans. Extremely few colonization models by C. coli have been reported to date. In food-producing animals, infection is mild or absent and thermotolerant Campylobacter colonize the intestines of animals. Colonization models are specific models that do not cause infection as they do not generally result in diarrhoea or other signs of disease. Therefore, this model will allow to evaluate the evolution of colonization by thermotolerant Campylobacter and the alternative tools development to antibiotics that limit their colonization in food-producing animals.

Comparison of two coprological methods for the diagnosis of Eurytrema ssp. in cattle and sheep.

Eurytrematosis is a disease caused by flukes of the genus Eurytrema. These parasites infect the pancreatic ducts of a wide variety of species, including cattle, sheep and humans. Diagnosing eurytrematosis through the analysis of faecal samples can be difficult because most of the available techniques are considered of low sensitivity. In this context, a modification of the Dennis, Stone and Swanson technique (Belem Sedimentation Technique, BST) was previously developed to increase the probability of detecting infected animals; nevertheless, the values of eggs per gram obtained using the modified technique are generally low. We proposed a modification of the this technique (MBST), to increase the sensitivity and detection rate of infected animals. The objective of this work was to describe MBST and compare it with BST. Faecal samples of 212 clinically healthy animals (174 from cattle and 38 from sheep) from 20 farms were taken by the intra-rectal route and stored at 4°C. The samples were processed using BST and MBST. Positive samples amounted to 55 (25.9%) using BST and 121 (57.1%) using MBST. In the simples from cattle, 52 (29.8%) and 107 (61.4%) were positive in BST and MBST, respectively. In sheep, three (7.8%) and 14 (36.8%) positive samples were obtained in BST and MBST, respectively.The results obtained using the two methods were significantly different, indicating a lack of agreement between their findings. The results suggest that MBST is a more sensitive method to detect Eurytrema spp. eggs in faeces than BST.

In vitro screening and in vivo colonization pilot model of Lactobacillus plantarum LP5 and Campylobacter coli DSPV 458 in mice.

The objective of this work was to determine the antibacterial effect of Lactobacillus plantarum strains of pork origin against Campylobacter coli strains, and to conduct experimental colonization pilot models in mice for both microorganisms. Inhibition assays allowed evaluation and selection of L. plantarum LP5 as the strain with the highest antagonistic activity against C. coli and with the best potential to be used in in vivo study. Adult 6-week-old female Balb/cCmedc mice were lodged in two groups. The treated group was administered with 9.4 log10CFU/2 times/wk of L. plantarum LP5. L. plantarum LP5 was recovered from the feces and cecum of the inoculated mice. However, when bacteria stopped being administered, probiotic counts decreased. Experimental colonization with C. coli was carried out in five groups of mice. All animals were treated with antibiotics in their drinking water to weaken the indigenous microbiota and to allow colonization of C. coli. Four groups were administered once with different C. coli strains (DSPV458: 8.49 log10CFU; DSPV567: 8.09 log10CFU; DSPV570: 8.46 log10CFU; DSPV541: 8.86 log10CFU, respectively). After 8 h, mice inoculated with different C. coli strains were colonized because the pathogen was detected in their feces. L. plantarum LP5 tolerated the gastrointestinal conditions of murine model without generating adverse effects on the animals. C. coli DSPV458 colonized the mice without causing infection by lodging in their digestive tract, thus generating a reproducible colonization model. Both models combined could be used as protection murine models against pathogens to test alternative control tools to antibiotics.

Molecular epidemiology of Campylobacter jejuni isolates from the broiler production chain: first report of MLST profiles in Argentina.

Campylobacter jejuni is an important foodborne pathogen with global distribution. We describe a genotyping study of a collection of C. jejuni (n=137) isolated from different broiler farms and from multiple sites along the processing line in a slaughterhouse in Argentina during 2011, 2012 and 2015. The isolates were genotyped using pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Based on the PFGE results, the isolates were grouped into 26 pulsotypes. Subsequently, the isolates representing these 26 pulsotypes were chosen for MLST genotyping, which identified 16 different sequence types (STs) and 6 clonal complexes (CCs) (21, 45, 48, 353, 354, 446). Several of the STs (n=7) have not been previously reported in the PubMLST.org database. The most prevalent CCs were 21, 45 (both associated with human campylobacteriosis worldwide) and 353. This study showed high genetic diversity among C. jejuni in the broiler production environment in Argentina with novel MLST genotypes.

A meta-analysis on the effectiveness of homofermentative and heterofermentative lactic acid bacteria for corn silage.

AIMS: This meta-analysis aims to assess the effect of lactic acid bacteria (LAB) inoculation on fermentation parameters, microbiological composition and aerobic stability of corn silage. METHODS AND RESULTS: Databases (PubMed, ScienceDirect and Scopus) were searched from 1980 to 2017. The criteria for inclusion were: randomized and controlled experiments using corn silage and published in peer-reviewed journals. The meta-analysis showed that LAB supplementation increased pH, acetate and propionate concentrations, and decreased acid detergent fibre, water-soluble carbohydrates and ammoniacal nitrogen (NH3 -N) compared to controls in the pooled raw mean difference random effect model. In addition, inoculation reduced counts of yeasts and moulds, increased LAB counts and markedly improved aerobic stability in corn silage. However, results indicated that the effect of inoculants may differ depending on the administration of homofermentative or heterofermentative LAB. CONCLUSIONS: For the development of functional bacterial inoculants, both types of LAB should be used. SIGNIFICANCE AND IMPACT OF THE STUDY: To our knowledge, this is the first meta-analysis to compare the application of homofermentative and heterofermentative LAB for corn silage.

Multicenter external validation of two malignancy risk prediction models in patients undergoing 18F-FDG-PET for solitary pulmonary nodule evaluation.

OBJECTIVES: To achieve multicentre external validation of the Herder and Bayesian Inference Malignancy Calculator (BIMC) models. METHODS: Two hundred and fifty-nine solitary pulmonary nodules (SPNs) collected from four major hospitals which underwent 18-FDG-PET characterization were included in this multicentre retrospective study. The Herder model was tested on all available lesions (group A). A subgroup of 180 SPNs (group B) was used to provide unbiased comparison between the Herder and BIMC models. Receiver operating characteristic (ROC) area under the curve (AUC) analysis was performed to assess diagnostic accuracy. Decision analysis was performed by adopting the risk threshold stated in British Thoracic Society (BTS) guidelines. RESULTS: Unbiased comparison performed In Group B showed a ROC AUC for the Herder model of 0.807 (95 % CI 0.742-0.862) and for the BIMC model of 0.822 (95 % CI 0.758-0.875). CONCLUSIONS: Both the Herder and the BIMC models were proven to accurately predict the risk of malignancy when tested on a large multicentre external case series. The BIMC model seems advantageous on the basis of a more favourable decision analysis. KEY POINTS: • The Herder model showed a ROC AUC of 0.807 on 180 SPNs. • The BIMC model showed a ROC AUC of 0.822 on 180 SPNs. • Decision analysis is more favourable to the BIMC model.

A surveillance system for diseases of companion animals in the Veneto region (Italy).

Experts and international public health organisations stress the lack of surveillance systems for companion animal diseases and the need to implement such surveillance as a priority of the 'One Health' perspective. This paper presents the features of a system for the collection, analysis, interpretation and dissemination of data regarding the health status of pets in the Veneto region (Italy). The system involved the construction of a Web-based database containing the diagnoses of transmissible and non-transmissible diseases of dogs and cats made by veterinarians in their practices, hospitals, kennels and catteries. Each diagnosis constitutes a single record, also containing data on the identification of the individual animal and on several characteristics of epidemiological relevance. The World Health Organization (WHO) 10th revision of the International Classification of Diseases (ICD-10) for human diseases has been adapted to canine and feline diseases to standardise the diagnostic nomenclature. Software has been specifically created for online data entry and data management. The first results show that the main disorders were digestive (21%), dermatological (18%) and cardiovascular (11%) among 1,087 diagnostic records in dogs, and digestive (23%), dermatological (15%) and urinary (14%) among 289 diagnostic records in cats. The main causes of death are represented by cardiovascular (21%) and gastrointestinal (21%) diseases in dogs and by urinary (31%) disorders in cats. At present, no institutional surveillance system for companion animal health exists in Italy, and veterinarians joining this project and sharing the outcomes of their clinical activity are acting on a voluntary basis.

Aussi bien les experts que les organisations internationales oeuvrant dans le domaine de la santé publique soulignent l'absence de systèmes de surveillance dédiés aux maladies des animaux de compagnie, alors que la mise en place de cette surveillance constitue une priorité dans une perspective « Une seule santé ¼. Les auteurs décrivent les caractéristiques d'un système introduit en Vénétie (Italie) pour collecter, analyser, interpréter et diffuser des données sur la situation sanitaire des animaux de compagnie. Le système repose sur une base de données en ligne alimentée par les rapports de diagnostic sur les maladies transmissibles et non transmissibles des chiens et des chats établis par les vétérinaires dans leur cabinet, à l'hôpital ou dans les élevages ou pensions pour chiens et chats. Chaque diagnostic fait l'objet d'une notification spécifique où sont également consignées les données d'identification individuelle de l'animal et les caractéristiques pertinentes au plan épidémiologique. La classification internationale statistique des maladies (ICD­10) de l'Organisation mondiale de la santé (OMS), qui concerne les maladies humaines, a été adaptée aux maladies des chiens et des chats afin d'utiliser une nomenclature standardisée des diagnostics. Un logiciel spécifique a été créé pour la saisie en ligne des données et leur gestion. D'après les premiers résultats, les principales affections diagnostiquées étaient, chez le chien (sur 1 087 rapports de diagnostic), des maladies digestives (21 %), dermatologiques (18 %) et cardio-vasculaires (11 %) et, chez le chat (sur 289 rapports de diagnostic), des maladies digestives (23 %), dermatologiques (15 %) et urinaires (14 %). Les principales causes de mortalité étaient respectivement les maladies cardio-vasculaires (21 %) et gastro-intestinales (21 %) chez le chien et les maladies du système urinaire (31 %) chez le chat. À l'heure actuelle, aucun système institutionnel de surveillance n'est en place en Italie pour les animaux de compagnie, de sorte que les vétérinaires qui participent à ce projet et partagent leurs résultats cliniques le font sur une base volontaire.

Tanto especialistas como organizaciones internacionales dedicadas a temas de salud pública hacen hincapié en la ausencia de sistemas de vigilancia de las enfermedades de los animales de compañía y en la necesidad de instaurar tal vigilancia como elemento prioritario de los planteamientos de «Una sola salud¼. Los autores presentan las características de un sistema destinado a reunir, analizar, interpretar y difundir datos sobre el estado de salud de los animales de compañía en la región italiana del Veneto. Para instituir ese sistema se creó una base de datos en línea que centraliza información sobre los diagnósticos de enfermedades transmisibles y no transmisibles de perros y gatos realizados por veterinarios en el ejercicio de su labor en consultorios, hospitales y residencias caninas y felinas. Cada diagnóstico constituye un registro único, que también contiene datos sobre la identidad del animal en cuestión y sobre una serie de aspectos de importancia epidemiológica. Con objeto de normalizar la nomenclatura de diagnóstico se adaptó a las enfermedades caninas y felinas la Clasificación Internacional de Enfermedades, décima revisión (CIE­10), de la Organización Mundial de la Salud (OMS), que se aplica a las enfermedades humanas. También se crearon programas informáticos destinados específicamente a la introducción de datos en línea y a su gestión. Los primeros resultados muestran que los principales trastornos en los perros, de los 1.087 diagnósticos registrados, fueron los digestivos (21%), seguidos de los dermatológicos (18%) y los cardiovasculares (11%). En el caso de los gatos, con 289 diagnósticos registrados, las dolencias más importantes fueron las digestivas (23%), las dermatológicas (15%) y las urinarias (14%). En el perro, las principales causas de mortalidad fueron las enfermedades cardiovasculares (21%) y gastrointestinales (21%), y en el gato las patologías urinarias (31%). Actualmente no existe en Italia ningún sistema institucional de vigilancia de la salud de los animales de compañía, y los veterinarios que participan en este proyecto y comparten los resultados de su praxis clínica lo hacen con carácter voluntario.

Poultry blood from slaughterhouses: development of a biopreservation system to improve microbiological quality prior to transforming blood into by-products.

The aim of this study was to investigate the use of indigenous lactic acid bacteria (LAB) with specific additives as a Biopreservation System (BS) for poultry blood during its storage in slaughterhouses. The BS consisted of two LAB (Enterococcus faecalis DSPV 008SA or Lactobacillus salivarius DSPV 032SA) with 4 additives (lactose 2 g/l, yeast extract 0.4 g/l, ammonium citrate 0.4 g/l and NaCl 1 g/l). After 24 h storage at 30ºC, lower counts of enterobacteria, coliforms, Pseudomonas spp. and Staphylococcus aureus were evident in blood treated with the BS than in untreated blood. The ability of LAB to prevent haemolysis was evident. A decrease in pH was associated with control of spoilage microorganisms but it needed to be regulated to prevent coagulation of proteins. On the basis of these results it is recommended to supplement blood with a BS to avoid undesirable changes during blood storage before processing.

Risk factors for work-related injury among farm workers: a 1-year study.

A 1-year prospective study was carried out to look for risk factors of farm-related injuries in Egusquiza, Santa Fe (Argentina). Information on demographic characteristics and occupational accidents was collected on (N=110, n=78) farm workers by means of personal interviews using a structured questionnaire. Monthly telephone contact was then maintained with the workers for 1 year to document all farm-related injuries. Data analysis included incidence rate, χ2 and logistic regression. Sixty-nine farm-related injuries were reported during the study period, six injuries being the maximum number affecting one worker. A total of 46.3% of the workers suffered at least one injury during the year. The incidence rate was 7.5 injuries/100 individual-month at risk. Medical assistance was needed in 26.8% of the cases and 5.8% of the injuries caused at least 1 day off work. Hospitalization for at least 1 day was required for 2.9% of the injured workers. Previous work-related injury in the family (p=0.005) (odds ratio (OR)=4.6, 95% confidence interval (CI)=1.6-13.3) and worker's activity (p=0.021) (OR=3.7, 95%CI=1.2-11.6) were associated with the dependent variable work injury. Agricultural and livestock farming are of great importance for the national economy. Workers' training on farm safety may play a key role to prevent work-related injuries and diseases.

Epidemiological description of cystic ovarian disease in argentine dairy herds: risk factors and effects on the reproductive performance of lactating cows.

To describe the epidemiology of cystic ovarian disease (COD), to find possible risk factors associated with the incidence of cysts and to analyse the impact of COD on the reproductive performance of dairy cows, databases from 22 dairy herds from the main dairy region in Argentina were retrospectively evaluated throughout a 3-year period (2009-2011). A total of 248 COD cases over 9156 parturitions were recorded, resulting in a cumulative incidence rate of 2.7%. Cystic ovarian disease incidence density was lower during the first 100 days post-partum (DPP) than during later stages of lactation. Seasonality had a significant influence on the disease presentation with higher incidence rates during winter and spring. Cows with a previous diagnosis of clinical mastitis showed 2.72 times more chances of developing ovarian cysts. Cystic cows had longer calving to first service and calving to conception intervals and lower conception rate than controls.

Probiotics and broiler growth performance: a meta-analysis of randomised controlled trials.

1. The aim of this meta-analysis was to investigate the effects of probiotics on the growth performance of broilers. PubMed, Scopus and Scholar Google databases were searched in all languages from 1980 to 2012. The studies in the meta-analysis were only selected if they were randomised and controlled experiments using broilers without apparent disease and the results were published in peer-reviewed journals. 2. A total of 48 and 46 studies were included to assess probiotic effects on body weight gain (BWG) and feed efficiency (FE), respectively. Probiotics increased BWG compared to controls (SMD = 0.661, 95% CI 0.499 to 0.822) and improved FE (SMD = - 0.281, 95% CI -0.404 to -0.157) in the pooled standardised mean difference random effect model, considering the source of heterogeneity and publication biases. However, there are evidences of publication bias and heterogeneity, so the results of this meta-analysis should be considered with caution. Applying the Duval and Tweedie's trim-and-fill methods, the adjusted value for BWG was 0.0594 (95% CI -0.122 to 0.242), and the adjusted value for FE did not show any modifications. 3. The meta-analysis showed that application of probiotics via water resulted in greater BGW and FE than administration through the feed. The effect was not related to the use of mono-strain or multi-strain probiotics, although it may depend on the strain used. The number of broilers and the duration of the experiments had an impact on the outcomes. 4. Additional studies should be conducted with the aim to identify the covariates which can explain the differences in the estimated effect sizes.

Mycotoxin sequestering agent: Impact on health and performance of dairy cows and efficacy in reducing AFM1 residues in milk.

The objectives of this study were to evaluate the exposure to a diet naturally contaminated with mycotoxins on lactation performance, animal health, and the ability to sequester agents (SA) to reduce the human exposure to AFM1. Sixty healthy lactating Holstein cows were randomly assigned to two groups: naturally contaminated diet without and with the addition of a SA (20 g/cow/d AntitoxCooPil® -60% zeolite-40% cell wall-). Each cow was monitored throughout lactation. The concentration of aflatoxin B1 (AFB1) in feed and M1 (AFM1) in milk, health status, and productive and reproductive parameters were measured. AFB1 concentration in feed was very low (2.31 µg/kgDM). The addition of SA reduced the milk AFM1 concentrations (0.016 vs. 0.008 µg/kg) and transfer rates (2.19 vs. 0.77%). No differences were observed in health status, production and reproduction performance. The inclusion of SA in the diet of dairy cows reduce the risk in the most susceptible population.

Enzyme-linked immunosorbent assay to diagnose human leptospirosis: a meta-analysis of the published literature.

We report an evaluation of the accuracy of ELISA for the detection of Leptospira-specific antibodies in humans. Eighty-eight studies published in 35 articles met all inclusion criteria and were submitted to meta-analysis. Pooled sensitivity and specificity were 0·779 (95% CI 0·770-0·789) and 0·913 (95% CI 0·908-0·917), respectively, and the area under the curve was 0·964. Heterogeneity across studies was statistically significant, but none of the sources of heterogeneity (disease stage, antigen used, antibody detected) could fully explain this finding. Although the convalescent stage of disease was significantly associated with higher diagnostic accuracy, IgM ELISA was the best choice, regardless of the stage of disease. Negative ELISAs (IgG or IgM) applied in the acute phase do not rule out leptospirosis due to the possibility of false-negative results. In this case it is advisable to request a second blood sample or to apply a direct method for leptospiral DNA.

Comparison between CT and CEUS in the diagnosis of pancreatic adenocarcinoma.

PURPOSE: The aim of this study is to compare CEUS and MDCT features of pancreatic ductal adenocarcinoma in relation to tumor size. MATERIALS AND METHODS: All patients with pathological diagnosis of pancreatic adenocarcinoma and studied by means of CEUS and MDCT were enrolled in this study. Two radiologists evaluated tumor size, site and imaging appearance. Patients in which at least one method yielded a positive result were divided into 4 groups on the basis of lesion size. For each dimensional category, sensitivity of the two imaging methods was calculated and compared using McNemar test. RESULTS: One hundred thirty-three patients were included in this study. In 9 of 133 patients neither MDCT nor US/CEUS could identify the lesion, while in 9 of 133 patients only MDCT and in 13 of 133 only US/CEUS could identify the lesion. In the remaining 102 patients, both MDCT and US/CEUS yielded a positive result. US/CEUS sensitivity was 86.47% while MDCT sensitivity was 83.58%, with no statistically significant difference (p = 0.523). For lesions smaller than 2 cm US/CEUS had a 100% sensitivity, while MDCT had a 73.33% sensitivity with no statistically significant difference (p = 0.125). For lesions between 2.1 and 3 cm US/CEUS had a sensitivity of 95.35%, while MDCT had a sensitivity of 83.72% with no statistically significant difference (p = 0.180). For lesions between 3.1 and 4 cm, US/CEUS had a sensitivity of 87.88%, while MDCT had a sensitivity of 93.94% with no statistically significant difference (p = 0.688). For lesions larger than 4 cm US/CEUS, had a sensitivity of 90.91%, while MDCT had a sensitivity of 100% with no statistically significant difference (p = 0.250). CONCLUSION: US/CEUS sensitivity in diagnosing pancreatic ductal adenocarcinoma is adequate and does not statistically differ from that of MDCT. US/CEUS sensitivity seems to be higher for small and medium lesions, while MDCT sensitivity is higher for large lesions. By combining both the imaging methods a higher accuracy in diagnosing pancreatic ductal adenocarcinoma can be expected.

Isometric evaluation of rotator cuff muscles in volleyball athletes.

AIM: The aim of the present study was to evaluate, in a group of semi-professional volleyball players, the function of the rotator cuff muscles with a new specific device. METHODS: We have studied 30 asymptomatic volleyball players, 15 females and 15 males, all right handed central or lateral spikers, with some specific functional tests. Every subject was evaluated by some common clinical tests to detect shoulder range of motion (ROM) and rotator cuff muscles strength in both sides. Athletes were also submitted to an isometric bilateral shoulder strength test, with a specific upper limb dynamometer (Dynatorq), in three different positions: 1) arm 0° abducted; 2) arm 90° abducted and 90° external rotation, to try to reproduce the spike gesture; 3) arm behind the thorax, as a simulation of clinical lift-off test. All clinical and instrumental data were collected in male and female groups and, in each group, comparisons between dominant and non dominant shoulders. RESULTS: Our data show in all athletes an initial postero-superior impingement with significant weakness of the subscapularis muscle in the dominant shoulder. CONCLUSION: In all overhead athletes, and in particular in volleyball spikers, a pre-clinical diagnosis of lack of strength of the subscapularis muscle in the dominant side, before the occurrence of pain or discomfort signs, could be an important diagnostic aspect to avoid or delay the back-retraction of the joint capsule of the shoulder.

Quantitative risk assessment of FMDV introduction in a FMD free country through bone-in beef and offal importation from a FMD free with vaccination country/zone.

Quantitative risk assessment was used to estimate the risk of introducing foot-and-mouth disease (FMD) through bone-in beef from Argentina (FMD-free with vaccination status) into other FMD-free countries. A stochastic model was built to characterize all the steps from primary production to bone-in beef export and introduction into an FMD-free country. The probability that bone-in beef from at least one animal infected with the FMD virus (FMDV) was exported during a year was 5.27 × 10-3 (95% CI <10-10 - 5.19 x 10-2) or in other words one case in 190 years. The risk of FMDV introduction was sensitive to the probability of an outbreak occurring in Argentina (r [Spearman´s rank correlation] = 0.99) and the number of herds affected during an outbreak (r = 0.10). Additionally, the probability that susceptible animals in the importing country came into contact with infective material (bones) and generated an outbreak was 6.16 × 10-4 (95% CI <10-10 - 6.20 ×10-3) or one FMD outbreak every 1623 years on average. Based on the quantitative risk assessment results, the probability of FMDV introduction into a FMD-free country where vaccination is not practiced from a FMD-free country where vaccination is practiced associated with bone-in beef trade from Argentina was negligible. The risk of an FMD outbreak caused by the potential introduction of the FMDV was associated with the existing conditions in the country. Thus, maintaining the FMD-free status with or without vaccination would not be relevant.

Effect of probiotic Lactiplantibacillus plantarum and chestnut flour (Castanea sativa mill) on microbiological and physicochemical characteristics of dry-cured sausages during storage.

The effect of chestnut flour (Castanea sativa Mill) on L. plantarum viability and physicochemical characteristics in a dry-cured sausage (Longaniza de Pascua) during storage is discussed. Four batches were prepared: CL with 3% chestnut flour added; CPL with 3% chestnut flour and 8.5 log CFU/g L. plantarum added; PL with 8.5 log CFU/g L. plantarum added and L, the batch control. The sausages were stored at 4 °C and 20 °C, and vacuum packed for 43 d. L. plantarum viability was affected by storage time (P < 0.001). However, higher L. plantarum counts at the final of storage were reached due to chestnut flour addition (P < 0.001). At room storage, chestnut flour caused a higher increase in TBARS values (P = 0.022). Nevertheless, all lipid oxidation treatments were in the range of accepted values at the sensory detection level. In conclusion, Longaniza de Pascua can be kept at 4 °C or 20 °C for 43 d without causing any rancidity problems.

Quantitative risk assessment for aflatoxin M1 associated with the consumption of milk and traditional dairy products in Argentina.

A quantitative risk assessment for exposure to aflatoxin M1 (AFM1) related to the consumption of milk and traditional dairy products of Argentina was developed. The frequency and concentration of AFM1 was modelled at various stages through the milk processes, considering Argentinean practices. Concentration of AFM1 (0.046 µg/l, 95%CI = 0.002-0.264 µg/l) in raw milk was estimated. The AFM1 concentration in milk was sensitive to the carry-over rate (r = 0.80), and milk yield in the first third of lactation during the spring-summer season (r = 0.11). AFB1 levels in silage (r = 0.22), pasture during the spring-summer season (r = 0.11), concentrate (r = 0.08), and cotton seed (r = 0.05) were the factors most correlated with AFM1 concentrations. Although the results showed that MoE values for the mean and median exposure to AFM1 were < 10,000 in infants, toddlers, and other children, the additional cancer risk due to exposure to AFM1 in infants, toddlers, and other children was 0.007, 0.005, and 0.0009 additional cases per year per 100,000 individuals, respectively, which indicates no health concern. In addition, the percentages of the population exceeding HI values (HI > 1) for exposure to AFM1 for infants, toddlers, and other children were 45%, 49.1%, and 40.6%, respectively. Under this scenario, the most susceptible population at risk was children < 10 years old; therefore, it is necessary to establish measures to prevent contamination of AFM1 in milk and milk products.

Possible reservoirs of thermotolerant Campylobacter at the farm between rearing periods and after the use of enrofloxacin as a therapeutic treatment.

Campylobacteriosis is a zoonosis and the most frequent cause of food-borne bacterial enteritis in humans. C. jejuni and C. coli are the most common species implicated in campylobacteriosis. Broilers and their products are considered the most important food sources of human infections. The aim of the present study was to evaluate the presence of thermotolerant Campylobacter in different reservoirs at the farm, and the permanence of this pathogen during four consecutive rearing periods. The samples were taken from the same house farm in the downtime period and during the last week of broiler rearing, prior to their slaughter during four consecutive cycles. Different reservoirs as potential sources of Campylobacter were analysed. The prevalence of Campylobacter in vectors was 23% in A. diaperinus larvae, 20% in wild birds, 13% in A. diaperinus adults, and 9% in flies; as regards fomites, the prevalence was 50% in workers' boots, 27% in litter, and 21% in feed, while in broilers it was 80%. Campylobacter jejuni was the most detected species (51%) in the samples analysed. In addition, some Campylobacter genotypes persisted in the house farm throughout consecutive rearing periods, indicating that those strains remain during downtime periods. However, our study could not identify the Campylobacter sources in the downtime periods because all the samples were negative for Campylobacter isolation. In addition, a remarkable finding was the effect of the use of enrofloxacin (as a necessary clinical intervention for flock health) in cycle 3 on the Campylobacter population. No Campylobacter could be isolated after that clinic treatment. Afterwards, we found a greater proportion of C. coli isolates, and the genotypes of those isolates were different from the genotypes found in the previous rearing periods. In conclusion, the effect of the use of enrofloxacin during the rearing period changed the Campylobacter species proportion, and this finding is particularly interesting for further evaluation. Furthermore, more studies should be conducted with the aim of detecting the Campylobacter sources between rearing periods.

Identification of the gamma irradiation dose applied to ground beef that reduces Shiga toxin producing Escherichia coli but has no impact on consumer acceptance.

The aims of the present study were: a) to estimate the minimal dose of gamma irradiation required to reduce 5 log CFU/g of native O157 and non-O157 Shiga toxin-producing Escherichia coli population in ground beef samples inoculated with high inoculum; b) to assess its effectiveness in samples with low inoculum and 3) to evaluate consumer acceptance. Based on the results, 1 kGy was estimated as the minimal dose of gamma irradiation required to reduce 5 log CFU/g of STEC in ground beef. However, when samples with low inoculum level were subjected to 1 kGy, 3.9% of the samples were positive for stx and eae genes after an enrichment step. Consumer acceptance analysis was carried out with samples subjected to 2.5 kGy and no significant differences were found between irradiated and control samples. Therefore, 2.5 kGy was identified as the gama irradiation dose that reduces STEC but has no impact on consumer acceptance of ground beef.