Spore-forming Bacillus cereus is a common contaminant of dairy products. As the microorganism is widespread in the environment, it can contaminate milk at the time of milking, but it can also reach the dairy products in each phase of production, storage and ripening. Milk pasteurization treatment is not effective in reducing contamination and can instead act as an activator of spore germination, and a potential associated risk still exists with the consumption of some processed foods. Prevalences and concentrations of B. cereus in milk and dairy products are extremely variable worldwide: in pasteurized milk, prevalences from 2% to 65.3% were reported, with concentrations of up to 3 × 10⁵ cfu/g, whereas prevalences in cheeses ranged from 0 to 95%, with concentrations of up to 4.2 × 10⁶ cfu/g. Bacillus cereus is also well known to produce biofilms, a serious concern for the dairy industry, with up to 90% of spores that are resistant to cleaning and are easily transferred. As the contamination of raw materials is not completely avoidable, and the application of decontamination treatments is only possible for some ingredients and is limited by both commercial and regulatory reasons, it is clear that the correct application of hygienic procedures is extremely important in order to avoid and manage the circulation of B. cereus along the dairy supply chain. Future developments in interventions must consider the synergic application of different mild technologies to prevent biofilm formation and to remove or inactivate the microorganism on the equipment.

The use of alternative feed ingredients in farm animal’s diets can be an interesting choice from several standpoints, including safety. In this respect, this study investigated the safety features of selected former food products (FFPs) intended for animal nutrition produced in the framework of the IZS PLV 06/14 RC project by an FFP processing plant. Six FFP samples, both mash and pelleted, were analysed for the enumeration of total viable count (TVC) (ISO 4833), Enterobacteriaceae (ISO 21528-1), Escherichia coli (ISO 16649-1), coagulase-positive Staphylococci (CPS) (ISO 6888), presumptive Bacillus cereus and its spores (ISO 7932), sulphite-reducing Clostridia (ISO 7937), yeasts and moulds (ISO 21527-1), and the presence in 25 g of Salmonella spp. (ISO 6579). On the same samples, the presence of undesired ingredients, which can be identified as remnants of packaging materials, was evaluated by two different methods: stereomicroscopy according to published methods; and stereomicroscopy coupled with a computer vision system (IRIS Visual Analyzer VA400). All FFPs analysed were safe from a microbiological point of view. TVC was limited and Salmonella was always absent. When remnants of packaging materials were considered, the contamination level was below 0.08% (w/w). Of note, packaging remnants were found mainly from the 1-mm sieve mesh fractions. Finally, the innovative computer vision system demonstrated the possibility of rapid detection for the presence of packaging remnants in FFPs when combined with a stereomicroscope. In conclusion, the FFPs analysed in the present study can be considered safe, even though some improvements in FFP processing in the feeding plant can be useful in further reducing their microbial loads and impurity. Graphical Abstract

Processed fish roes are acquiring considerable importance in the modern food market, entering more and more often as an ingredient in food preparation and as caviar substitutes. In this study, we defined quality, traceability and safety issues related to processed fish roe products from different species. The results obtained allowed to distinguish eggs originated from different fish species and to discriminate between fish roes and caviar samples obtained from four different sturgeons species. We observed that roes showed a trend of grouping according to ecological and reproductive habits of fish species. We highlighted the differences between eggs originated by farmed and freshwater fish, enriched in n6 polyunsaturated fatty acids (PUFAs), and all the others, in which n3 PUFAs were prevalent. In addition, we evaluated processed fish roes under a food safety point of view, combining microbiological analysis with the determination of organic acids, used in some products as authorized preservatives. Microbiological characterization has proved a general good hygienic level for these products. Organic acids determination showed values in compliance with European Union (EU) regulations in almost of samples; in some cases, we found a mismatch between the organic acids detected and what was reported in labels. Processed fish roes could be considered a safe product that can provide to human nutrition a valuable content of essential fatty acids.

The aim of this study was to evaluate the effects of the administration of a species-specific probiotic (Lactobacillus animalis SB310, Lactobacillus paracasei subsp. paracasei SB137 and Bacillus coagulans SB117 in a 30:35:35 ratio, respectively; 1.8 × 1010 CFU/g of powder) on gut microbial balance, immune response and growth performance of Holstein female calves during the first month of life. Twenty-two calves were divided into two experimental groups from 2 to 28 days of life: control (C), fed with milk replacer and concentrate as a basal diet, and treatment (T), fed C diet plus 1 g/calf/day of probiotic powder for the first month of age. Faecal and blood samples were individually collected and analysed weekly. Individual faecal score was recorded daily and general health score was calculated at the end of the trial. Cell-mediated immune response was evaluated by skin test at 7 and 28 days of life. Milk replacer and concentrate intake were recorded daily, while body weight and biometrical parameters were recorded at 2, 8, 14, 21 and 28 days of life, thus average daily gain and feed conversion rate were calculated. During the first week of treatment, lower blood eosinophil percentage (0.05% vs. 0.22%; P≤0.01) was found in T group, while basophils were higher in T than C group at the end of the trial (0.21% vs. 0.16%; P≤0.05). Higher faecal lactic acid bacteria (LAB)/E. coli ratio on day 28 of life (3.73 log CFU/g vs. 2.02 log CFU/g; P≤0.05) and lower incidence of diarrhoea were found in the treated group (63.30% vs. 70.71%; P=0.05). Body weight (48.92 kg vs. 46.92 kg; P≤0.05), total concentrate intake (14.77 kg vs. 12.56 kg on dry matter basis; P≤0.05), and heart girth (81.16 cm vs. 78.49 cm; P≤0.05) were significantly higher in T group. The administration of the probiotic during the first month of life improved gut microbiota and increased the growth performance and some biometric parameters of calves.

This study evaluated the prevalence of potential pathogenic bacteria (mainly Campylobacter spp., but also Listeria monocytogenes and Salmonella) in wild boar (Sus scrofa) and the hygiene of carcasses of wild boar hunted in a hill area of northern Italy during a hunting season (October to December). In total, 62 animals were submitted to microbiological analyses of the tonsils (detection of Listeria spp. and Listeria monocytogenes), caecal content (detection of Salmonella and Campylobacter spp.), mesenteric lymph glands (detection of Salmonella), and carcasses. In addition to analyzing pathogen prevalence and carcass hygiene of these animals, we performed an enumeration of total viable count (TVC), Enterobacteriaceae, Escherichia coli, coagulase-positive staphylococci, and spores of sulfite-reducing clostridia. Influencing factors considered were sex, weight, and age of the animals and environmental temperature on the day of hunting. A high prevalence was observed for L. monocytogenes in tonsils (...