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Listeria monocytogenes is an important food-borne pathogen causing meningitis, meningo-encephalitis and abortion. Both sporadic and epidemic human listeriosis cases are associated with the consumption of contaminated foods. To assess the potential risk to consumer health, the presence of L. monocytogenes was investigated using qualitative and quantitative methods in raw milk (bulk tank milk and milk for vending machine) collected from 2010 to 2013 in Northern Italy (Lombardy and Emilia-Romagna regions). Overall, L. monocytogenes was detected in 145 on 8716 of raw milk samples, with a prevalence of 1.66% (95% C.I. 1.4%–1.7%). The prevalence ranged from 0.52% (95% C.I. 0.3%–0.9%) in 2012 to 2.7% (95% C.I. 2.0%–3.8%) in 2013, but no trend of increase was observed in four-years of investigation. The pathogen was detected from 2.2% (95% C.I. 1.9%–2.6%) of bulk tank milk and from 0.5% (95% C.I. 0.3%–0.8%) of milk for vending machine. A significative difference (p

The recent outbreak of Salmonella Agona linked to the consumption of infant formula (powdered formula) has rekindled the attention about the correct procedures for preparation and use of these products. International guidelines have already been published so far, particularly in association with Cronobacter sakazakii in early 2000s. FAO/WHO suggested to reconstitute formula with water at no less than 70°C. We therefore contaminated powdered formula with low levels of Salmonella spp and C sakazakii to evaluate the pathogens inactivation during the formula preparation using water at 70°C. In these conditions we observed a survival of both pathogens, indicating that the suggested recommendations may be not enough to guarantee the safety of this product. Higher temperatures are needed to reduce the biological risk, even if it may be not easily realized in actual domestic conditions. Moreover, the impact on the nutritional value of reconstituted formulas should be evaluated.

The aims of this study were to (1) study the optimal growth condition for two Lactococcus lactis strains to produce the anti-listeria compounds and (2) evaluate the effect of films activated with a twofold concentrated cell-free supernatant of La. lactis to inhibit Listeria monocytogenes. For the growth conditions, skimmed milk added to either Ml7 or MRS provided the highest levels of anti-listeria activity assayed (800 arbitrary unit per milliliter) for both La. lactis strains. A significant decrease of Li. monocytogenes counts was observed in cheese packed in films treated with an average decrease of 2.12 log colony-forming unit per gram after 15 days of storage. Practical Applications The antimicrobial film for food packaging can be used for the preservation of perishable foods such as the sliced cheese. This film developed in our study inhibits Listeria monocytogenes growth in sliced cheese, and does not have an adverse effect on the lactic microbiota, contributing to the preservation of the quality of the product. Thus, it could be a useful tool for the control of the development of pathogens in foods during storage of dairy products.

The aim of this study was to evaluate the behaviour of Escherichia coli, Salmonella Typhimurium and Listeria monocytogenes in an innovative semi-dry reduced fat Italian salami. The product is made from pork meat and it is characterized by less than 20% fat, lactose-, gluten- and milk protein-free. It is developed in Italy according to EC Regulation No. 1924/2006 “on nutrition and health claims made on foods”. Multi-strain cocktails of each pathogen were used to inoculate (5 log cfu g−1) separately the salami batter. During the manufacture and ripening, E. coli, S. Typhimurium, and L. monocytogenes decreased by 2.5, 1.65 and 0.5 log cfu g−1 respectively from the initial inoculated levels. Experimental data indicated that, during the shelf life in a condition of moderate thermal abuse (8–12 °C), the portioned and vacuum packed low fat salami are not able to support the growth of L. monocytogenes.

As reported on RASFF's portal, in the first 9months of 2016, a total of 13 "alerts/information for attention" were issued concerning the presence of Listeria monocytogenes in mould cheeses throughout Europe. This study analyzes the behaviour of L. monocytogenes in Gorgonzola cheese, a typical Italian soft blue-veined cheese, when contaminated at different time points. In the first challenge test, the pasteurized milk was contaminated and the complete cheese manufacture (cheesemaking, ripening) and shelf life was simulated. After a decrease during the first days of the cheesemaking, the pH remained constant for 35days (5weeks) and then it increased rapidly reaching the final values of 6.8±0.02 in the core and 5.8±0.4 on the rind. At the same time, the pathogen concentration decreased (about 2logCFU/g), although during the last week a rapid pathogen growth was observed after the rise in pH values. When the cheese was stored at thermal abuse condition (8-12°C), the pathogen concentration on the rind was 4.8±0.3 log CFU/g and after 66days (about 9weeks) no significant difference (p>0.05) was observed; whereas, a growth from 5.4±0.4 to 7.1±0.5logCFU/g was observed in the core. A second challenge test was performed using three batches of commercial slices of Gorgonzola cheese inoculated by L. monocytogenes and stored at 8°C. The maximum specific growth rates (μmax, 1/h) of L. monocytogenes estimated ranged from 0.007 to 0.061. The square root model was used to predict the μmax at others temperature and to establish the time necessary to reach the European critical legal limit of 2logCFU/g, in different storage scenarios. The predictions obtained in this study can be applied to any time-temperature profile, and in particular to the conditions to which the product is most likely to be subject in normal use, up to its final consumption. This study can be considered a valuable contribution also aimed at supporting the monitoring surveys carried out by officers of the Regional Veterinary Authority.

In the last years, consequently to EC Regulation no. 1924/2006 on nutrition and health claims made on foods, some Italian food businnes operators (FBOs) leaders in the meat sector, invested in research to develop innovative products such as low fat salami, containing up to 30% less fat than the traditional one. For FBOs it is essential to demonstrate for each production process whether the substrate allows the growth of L. monocytogenes and whether L. monocytogenes could reach or exceed the limit of 100 cfu g–1 at the end of the shelf life, as stated by EC Regulation no. 2073/2005. In the present study, the growth potential of L. monocytogenes during the shelf life of low fat salami packed in modified atmosphere was evaluated. The results show that the product is unable to support the growth of pathogen, even if the storage temperature is between 8 and 12°C.

In order to simulate a contamination at the processing plant, one batch of freshlyprocessed salami batter (20 kg) was inoculated (1% v:w) with 5 log colony forming unit (CFU)/g of a multi-strain cocktail of two strains of Escherichia coli O157:H7 (registered and wild strain). Another batch was inoculated (1% v:w) with sterile physiological saline solution and used to check the lactic acid bacteria (Lab) behaviour and the changes of physicochemical parameters (pH and aw). Both batches were then processed to obtain a semi-dry salami (Hungarian-style): microbiological and physico-chemical properties were monitored during 94 days of ripening. During the manufacturing process, the levels of pathogen decreased of about 2.18 log CFU/g with respect to the initial inoculated levels. The behaviour of the indigenous bacteria such as Lab and the physico-chemical properties can help to determine the fate of pathogens throughout processing.

Pooled milk samples from 115 Bergamasca meat sheep were collected aseptically five times from lambing to weaning to determine the prevalence of intramammary infection, somatic cell counts and milk quality parameters (protein, fat and lactose), and effects of infection on lamb weight gain. The global prevalence of subclinical intramammary infection was 51·2%. The Staphylococcus genus was responsible for the greatest prevalence (53·3% among infected udders). Staphylococcus aureus was isolated in 8·4% of infected milk samples. Infection status had significant effects on fat and protein percentage and on somatic cell count. Lamb growth was greatest for lambs of ewes with no infection and decreased as the number of infected samples increased. No significant differences were detected in the growth of lambs with dams infected by different bacterial species.

The behaviour of Listeria monocytogenes and Escherichia coli O157:H7 was studied during the manufacture and ripening of two traditional Italian Alps cheeses. Each cheese type was manufactured in a pilot plan from raw cow milk (without the addition of starter cultures) artificially inoculated with L. monocytogenes and E. coli O157:H7 to a final concentration of about 4 log CFU/mL. The pathogens were enumerated throughout the cheese making and ripening processes to study their behaviour. When the milk was inoculated with 4 Log CFU/mL, the pathogens counts increased in the first time during the manufacturing process and then remained constant, until the end of ripening, or decreased significantly. Results indicate that the environment and nature of food borne pathogens affected the concentration of the bacteria during the manufacturing and ripening process. Thus, the presence of low cells numbers of L. monocytogenes and E. coli O157:H7 in milk destined for the production of raw milk cheeses characterized by a cooking of the curd less than 48°C can constitute a hazard for the consumer.