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Epizootic haemorrhagic disease virus (EHDV) is a member of the Orbivirus genus in the Reoviridae family, and it is the etiological agent of an arthropod-transmitted disease that affects domestic and wild ruminants. Due to its significant economic impact, many attempts have been done in order to develop diagnostic immunoassays mainly based on the use of the viral protein 7 (VP7), that is, the immunodominant serogroup-specific antigen. In this work, a recombinant VP7 (recVP7) of EHDV serotype 2 was produced in a baculovirus system, and after purification using ion metal affinity chromatography, we obtained a high yield of recombinant protein characterized by a high degree of purity. We used the purified recVP7 as reagent to develop a competitive enzyme-linked immunoassay (c-ELISA), and we tested the presence of EHDV antibodies in 185 dromedary camel serum samples. The c-ELISA showed good performance parameters in recognising positive sera of naturally EHDV-infected dromedary camels; in particular, our developed test reached 85.7% of sensitivity, 98.1% of specificity, 93% of accuracy, and a high agreement value with results obtained by the commercial ELISA kit (Cohen’s kappa value of 0.85) that we adopted as the reference method. This c-ELISA could be a useful screening test to monitor the virus spread in camels that are sentinel animals for endemic areas of disease.

Human listeriosis outbreaks are often associated with food products, which could be contaminated, at the same time, also by different clones of Listeria monocytogenes. This emphasize the need to type more than one L.monocytogenes isolate found in a single food or environmental sample. The purpose of the present study was to evaluate the presence of different L.monocytogenes strains in food and food production environment in order to understand if there is need to type more isolates from the same sample in case of presence of L.monocytogenes. Between 2011 and 2015, at the Italian National Reference Laboratory for L.monocytogenes, for each positive sample, from two to twenty-three isolates of L.monocytogenes were collected. All the isolates were characterized by conventional serotyping and pulsed field gel electrophoresis (PFGE). Moreover, isolates from the same sample, having indistinguishable PFGE profile, were subjected to whole genome sequencing in order to perform core genome Multi Locus Sequence Typing (cgMLST). Within each sample, more than one serotype and one pulsotype were found in 11.9% and 27.5%, respectively. For indistinguishable PFGE patterns the cgMLST analysis showed 96.2% of concordance demonstrating the added value of new sequencing technologies. This study has demonstrated the need to select and type more than one L.monocytogenes colony in one food or food environmental sample to detect the diversity of L.monocytogenes strains and facilitate downstream investigations and effective source attribution in foodborne outbreak inquiry.

Pecorino di Farindola is a typical cheese produced in the area surrounding the village of Farindola, located in the Abruzzo Region (central Italy), unique among Italian cheese because only raw ewe milk and pig rennet are used for its production. In the literature it is well documented that raw milk is able to support the growth of pathogenic microorganisms such as Listeria monocytogenes. Predictive microbiology can be useful in order to predict growth-death kinetics of pathogenic bacteria, on the basis of known environmental conditions. Aim of this study was to compare predictions obtained from a model, originally designed to predict the kinetics of L. monocytogenes in the dynamic growth-death environment of drying fresh sausage, with the results of challenge tests performed during the ripening of Pecorino di Farindola produced from artificially contaminated raw ewe milk. A challenge test was carried out using ewe raw milk inoculated with L. monocytogenes, in order to produce Pecorino di Farindola cheese stored at 18 °C for 149 days of ripening. During the ripening period, pH and aw values decreased in all samples analysed; lactic acid bacteria become the prevailing microbial population, while for L. monocytogenes a period of stability (neither growth nor death) followed the initial situation. The growth inhibition and the following inactivation may mostly be due to competition with the autochthonous microbiota and to the reduction of water activity. Mathematical modelling was used in order to predict microbial kinetics in the dynamic ripening environment, joining growth and death patterns in a continuous way, and including the highly uncertain growth/no growth range separating the two regions. The effect of lactic acid bacteria on the growth of pathogens was also included. Predicted microbial kinetics were satisfactory, as confirmed by the absence of statistically significant difference between observed and predicted values (p > 0.05). The present study proved, via challenge tests, that a dynamic growth/death model, previously used for a meat product, can be fruitfully used in cheese characterized by active competitive microbiota and progressive drying during ripening.

Among pathogens, L. monocytogenes has the capability to persist on Food Processing Environment (FPE), first of all posing safety issues, then economic impact on productivity. The aim of this work was to determine the influence of biofilm forming-ability and molecular features on the persistence of 19 Listeria monocytogenes isolates obtained from FPE, raw and processed products of a cold-smoked salmon processing plant. To verify the phenotypic and genomic correlations among the isolates, different analyses were employed: serotyping, Clonal Complex (CC), core genome Multi-Locus Sequence Typing (cgMLST) and Single Nucleotide Polymorphisms (SNPs) clustering, and evaluation of the presence of virulence- and persistence-associated genes. From our results, the biofilm formation was significantly higher (*P 0.05) at 37 °C, compared to 30 and 12 °C, suggesting a temperature-dependent behaviour. Moreover, the biofilm-forming ability showed a strain-specific trend, not correlated with CC or with strains persistence. Instead, the presence of internalin (inL), Stress Survival Islet (SSI) and resistance to erythromycin (ermC) genes was correlated with the ability to produce biofilms. Our data demonstrate that the genetic profile influences the adhesion capacity and persistence of L. monocytogenes in food processing plants and could be the result of environmental adaptation in response to the external selective pressure.

Traditional Italian pork products can be consumed after variable drying periods, where the temporal decrease of water activity spans from optimal to inactivating values. This makes it necessary to A) consider the bias factor when applying culture-medium-based predictive models to sausage; B) apply the dynamic version (described by differential equations) of those models; C) combine growth and death models in a continuous way, including the highly uncertain growth/no growth range separating the two regions. This paper tests the applicability of published predictive models on the responses of Listeria monocytogenes and Yersinia enterocolitica to dynamic conditions in traditional Italian pork sausage, where the environment changes from growth-supporting to inhibitory conditions, so the growth and death models need to be combined. The effect of indigenous lactic acid bacteria was also taken into account in the predictions. Challenge tests were carried out using such sausages, inoculated separately with L. monocytogenes and Y. enterocolitica , stored for 480 h at 8, 12, 18 and 20 °C. The pH was fairly constant, while the water activity changed dynamically. The effects of the environment on the specific growth and death rate of the studied organisms were predicted using previously published predictive models and parameters. Microbial kinetics in many products with a long shelf-life and dynamic internal environment, could result in both growth and inactivation, making it difficult to estimate the bacterial concentration at the time of consumption by means of commonly available predictive software tools. Our prediction of the effect of the storage environment, where the water activity gradually decreases during a drying period, is designed to overcome these difficulties. The methodology can be used generally to predict and visualise bacterial kinetics under temporal variation of environments, which is vital when assessing the safety of many similar products.

The present study evaluated the occurrence of zoonotic parasites in feces and on fur of stray and private dogs living in Italy. Individual fecal samples collected from 117 and 385 kenneled (i.e., rescue shelter) and privately owned dogs, respectively, were examined by conventional copromicroscopy. Samples positive for Giardia duodenalis and Cryptosporidium spp. were subjected to further genetic characterization. Additionally, 174 fur samples of private and kenneled dogs living in the same area, 27 of which were also subjected to copromicroscopical examinations, were examined for the presence and viability of parasite elements. Out of 502 fecal samples, forty-one (8.2 %) scored positive for G. duodenalis cysts while one (0.2 %) for Cryptosporidium oocysts. Nine private dogs were molecularly positive for G. duodenalis assemblage C (n. 7), assemblage D (n. 1), and assemblages C + D (n. 1), while 11 kenneled dogs were positive for assemblage C (n. 8), assemblage D (n. 1), and assemblages C + D (n. 2). Cryptosporidium spp. were identified as C. canis in a private dog. One hundred and seventy-two dogs (34.3 %), i.e., 92 private and 80 kenneled, were positive for zoonotic nematodes: Toxocara canis (6.6 %), Ancylostoma caninum (6.8 %), and Capillaria aerophila (0.6 %). Unviable eggs of Toxocara spp. were found on the hair of five (2.9 %) private dogs. The present findings indicate that canine feces from both private and kenneled animals may contain zoonotic parasites and may be a potential risk for humans and other animals, especially when they contaminate the environment. The role of dog fur as source of human infections should be further investigated.

Background Contagious Bovine Pleuropneumonia (CBPP), caused by Mycoplasma mycoides subsp. mycoides, is widespread in sub-Saharan Africa. The current live vaccine T1/44 has limited efficacy and occasionally leads to severe side effects in the animals. A better understanding of the immune responses triggered by Mycoplasma mycoides subsp. mycoides and their role in disease progression will help to facilitate the design of a rational vaccine. Currently, knowledge of cytokines involved in immunity and immunopathology in CBPP is rather limited. The aim of this study was to characterize the in vivo plasma concentrations of the cytokines TNF-α, IFN-γ, IL-4, IL-10 and the overall role of CD4+ T cells in the development of cytokine levels during a primary infection. Plasma cytokine concentrations in two groups of cattle (CD4+ T cell-depleted and non-depleted cattle) experimentally infected with Mycoplasma mycoides subsp. mycoides were measured and their relationship to the clinical outcomes was investigated. Results Plasma cytokine concentrations varied between animals in each group. Depletion of CD4+ T cells did not induce significant changes in plasma levels of TNF-α, IL-4, and IL-10, suggesting a minor role of CD4+ T cells in regulation or production of the three cytokines during the time window of depletion (1-2 weeks post depletion). Unexpectedly, the IFN-γ concentrations were slightly, but statistically significantly higher in the depleted group (p < 0.05) between week three and four post infection. Three CD4+ T cell-depleted animals that experienced severe disease, had high levels of TNF-α and IFN-γ. Only one severely diseased non-depleted animal showed a high serum concentration of IL-4 post infection. Conclusions Comparison of most severely diseased animals, which had to be euthanized prior to the expected date, versus less severe diseased animals, irrespective of the depletion status, suggested that high TNF-α levels are correlated with more severe pathology in concomitance with high IFN-γ levels.

Naples and Caserta provinces are extensively affected by the illegal dumping of hazardous and urban wastes, which were periodically set to fire. Several studies were made on the possible health impact of this illegal waste management. The aim of the study was to detect dioxins levels in breast milk of volunteer primiparae and to assess the possible source of dioxins in the affected areas. The authors determined dioxins levels in breast milk from 100 primiparae from the study area and collected anamnestic information on donors. We determined dioxins levels in breast milk from 100 primiparae from the study area and collected anamnestic information on donors. As a measure of environmental risk of dioxins (EDR) we used the interpolated values of dioxins concentration in buffalo milk samples collected in the study area. Correlations between the EDR, age of the mother, smoking habit, cheese consumption, occupation in activity at risk, presence of plants for the disposal of toxic waste or illegal burning of solid waste near the residence of the donor and dioxin level in breast milk were investigated. The dioxin level in breast milk is significantly correlated to the EDR, the age of the sampled women and the presence of illegal burning of solid waste.

Italian style fresh sausage is a traditional pork product that is frequently consumed raw, usually after drying. So far, the prediction of the behaviour of microorganisms in varying environments has been carried out through separate growth or death models. The aim of this study is to show how to combine these, in order to describe the kinetics of Yersinia enterocolitica and Listeria monocytogenes in sausage during the drying period. During this time, the storage temperature and the pH are fairly constant, while the water activity decreases, being the primary cause of shifting the organisms’ kinetics from growth to inactivation. The water activity takes up values from growth (RG), uncertainty (R0) and death (RD) regions. In the uncertainty region, neither growth nor death is predicted. Among the native flora, lactic acid bacteria may have significant effect on these kinetics. Here we show how to generate predictions for such scenarios, from data that are generated in constant environments. Thus the predictions in our dynamic environments are extrapolations and could be problematic if the environmental fluctuation is extreme. Our approach can be used to predict bacterial growth/death kinetics under temporal variation of storage environments, which is vital when assessing the safety of fresh sausage. We envisage similar applications to other RTE meat products, too.