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Gram-positive foodborne pathogens such as Listeria monocytogenes and Staphylococcus aureus can grow in a wide variety of foods, including raw milk. The aim of the study was to compare the growth of L. monocytogenes and S. aureus inoculated in donkey and cow samples of raw milk during a storage time of 11 days at 8 °C. Moreover, the study aimed to evaluate the influence of lactic acid bacteria (LAB) content on the growth of the two microbiological populations considered. LAB content was lower in raw donkey milk than in raw cow's milk during the entire analyses; on the other hand, pH levels were higher in the donkey milk rather than in the cow's milk, although both values showed a decrease at the day 11. S. aureus showed no significant differences in the two types of milk. From day 0 to 11, L. monocytogenes increased from 3.68 ± 0.02 log CFU/mL to 6.31 ± 0.07 log CFU/mL and from 3.64 ± 0.04 log CFU/mL to 4.59 ± 1.04 log CFU/mL, in donkey milk and in cow's milk, respectively. Our results showed that donkey milk is a more favourable matrix to support the growth of L. monocytogenes than cow's milk.

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 (μ max , 1/h) of L. monocytogenes estimated ranged from 0.007 to 0.061. The square root model was used to predict the μ max 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., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Two quantitative risk assessment (RA) models were developed to describe the risk of salmonellosis and listeriosis linked to consumption of raw milk sold in vending machines in Italy. Exposure assessment considered the official microbiological records monitoring raw milk samples from vending machines performed by the regional veterinary authorities from 2008 to 2011, microbial growth during storage, destruction experiments, consumption frequency of raw milk, serving size, and consumption preference. Two separate RA models were developed: one for the consumption of boiled milk and the other for the consumption of raw milk. The RA models predicted no human listeriosis cases per year either in the best or worst storage conditions and with or without boiling raw milk, whereas the annual estimated cases of salmonellosis depend on the dose-response relationships used in the model, the milk storage conditions, and consumer behavior in relation to boiling raw milk or not. For example, the estimated salmonellosis cases ranged from no expected cases, assuming that the entire population boiled milk before consumption, to a maximum of 980,128 cases, assuming that the entire population drank raw milk without boiling, in the worst milk storage conditions, and with the lowest dose-response model. The findings of this study clearly show how consumer behavior could affect the probability and number of salmonellosis cases and in general, the risk of illness. Hence, the proposed RA models emphasize yet again that boiling milk before drinking is a simple yet effective tool to protect consumers against the risk of illness inherent in the consumption of raw milk. The models may also offer risk managers a useful tool to identify or implement appropriate measures to control the risk of acquiring foodborne pathogens. Quantification of the risks associated with raw milk consumption is necessary from a public health perspective.

The safety of raw milk sold in Northern Italy was investigated in relation to hygiene quality parameters and presence of Salmonella spp., Listeria monocytogenes, thermotolerant Campylobacter, and Verocytotoxin producing Escherichia coli O157:H7. The performance of different analytical methods used-official culture method (ISO), modified Bacteriological Analytical Manual cultural method (mBAM), and polymerase chain reaction (PCR)-was evaluated. The presence of Mycobacterium avium subsp. paratuberculosis (Map) was investigated only by PCR. All samples met regulations for alkaline phosphatase and inhibitory substance, while 18% and 44.8% of samples collected from vending machines had, respectively, somatic cell count (SCC) >300,000/mL and total bacterial count (TBC) >50,000 CFU/mL. The correlation between hygienic quality parameters in samples collected from bulk tank and vending machines showed a significant increase of TBC in vending machines meaning that raw milk was mishandled during distribution and sale. All pathogens investigated were detected in raw milk sold at vending machines; a total of five samples (5%) had at least one pathogen, of which two were detected by PCR and three by mBAM. None of the samples was positive by cultural ISO methods. Even if the comparison of analytical methods showed that none performs significantly better than the others, testing a higher volume of milk (25 versus 210 mL) affects significantly the detection rate of pathogens. Three samples (3%) were positive for Map, suggesting that raw milk is a significant source of Map exposure for consumers. The observed TBC increase and the detection of several pathogenic bacteria pose questions on the safety of raw milk; the use of ISO seems inefficient in detecting a low contamination level of pathogens in milk and consequently not appropriate as official method for testing. In order to ensure consumer's safety, a new approach for the raw milk chain is required.

During the manufacture of Italian salami, a traditional meat product, a sequence of hurdles like meat fermentation, air-drying, and long ripening processes are generally sufficient to inhibit the growth of most pathogens. Furthermore, Italian salami are traditionally produced by adding synthetic nitrates/nitrites to raw meat with safety and technological aims, even if controversial opinions about their use still remain, particularly in relation to the consumer demand for natural food products. In this context, the aim of the study was to investigate the inactivation of Listeria monocytogenes and Salmonella spp. during the manufacturing process of Milano-type salami made with different formulations to evaluate the contribution of the hurdles and the vegetable or synthetic additives on the inactivation of pathogens. Thus, a challenge study was performed dividing ca. 400 kg of Milano-type salami batter into three batches: Batch (A) without nitrates/nitrites; Batch (B) with vegetable nitrates, and Batch (C) with synthetic nitrates/nitrites. The batches were separately inoculated with L. monocytogenes and Salmonella spp. and the pathogens' survival was evaluated during the fermentation, draining, and 70-day ripening of the Milano-type salami. The pathogen counts decreased in all tested conditions, even though the highest inactivation of L. monocytogenes and Salmonella spp. (p < 0.05) was observed when nitrates or nitrites were added to the batter. This study shows how the safety of these products cannot exclude the aspect of the hurdle technology during the process, which plays a major role in the reduction of pathogens, but additives like nitrates and nitrites allow for a greater margin of safety. Thus, further studies are needed to validate the use of natural compounds as alternatives to conventional preservatives in meat products. These results may provide new information to support food business operators in producing traditional foods with alternative preservatives and competent authorities in verifying the safety of the products made with natural compounds, and to control the process parameters responsible for the synergistic effect against pathogens such as L. monocytogenes and Salmonella spp. [ABSTRACT FROM AUTHOR]

Formaggio di Fossa di Sogliano is a traditional Italian Protected Designation of Origin (PDO) cheese ripened for a minimum of 5 months, with the feature of a ripening of at least 80 to at most 100 days in pits, digged into tuffaceous rocks according to medieval tradition of Italy. In this study, a challenge test using Listeria innocua as a surrogate of Listeria monocytogenes was performed, with the aim of increasing knowledge concerning the impact of the Fossa cheese process, and especially of the traditional ripening process of this PDO, on the behaviour of L. monocytogenes. Pasteurized milk was experimentally inoculated with 4.5 log CFU/mL cocktail by three L. innocua strains, and L. innocua and Mesophilic Lactic Acid Bacteria (LAB) counts as well as the evolution of temperatures, pH and aw values were monitored throughout the manufacturing and ripening processes. Throughout the ripening in maturation room a constant temperature of 8°C was observed reaching a temperature between 10 and 15.5°C during ripening into pit. In the final products data for LAB concentration, pH and aw values were roughly in accordance with literature, even if some differences were, probably due to variability of artisanal cheese productions. The numbers of L. innocua showed a slight decrease but remained stable until the end of ripening in maturation room, whereas a significant reduction of the microorganism was observed in the final product, at the end of the ripening into the pit. The findings give scientific evidence that the process of this PDO prevented the L. innocua growth, allowing us to speculate a similar behaviour of L. monocytogenes. Based on this study, the recommendation to extend as much as possible the ripening into pit (from 80 to 100 days) was provided to food business operators as a risk mitigation strategy to be implemented. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

All dairy farms authorized to produce and sell raw milk in a province of Northern Italy were investigated to determine the presence of Campylobacter spp., verocytotoxin-producing Escherichia coli (VTEC), Listeria monocytogenes, and Salmonella spp. in in-line milk filters and to assess their association with suspected risk factors on farms. A logistic regression model was used to analyze data collected describing the characteristics and management practices of 27 farms and the microbiological status of 378 in-line milk filters by both culture-based and molecular methods. Thermotolerant Campylobacter, VTEC, and L. monocytogenes were detected in 24 (6.45%), 32 (8.4%), and 2 (0.5%) samples, respectively. No Salmonella spp. were detected. For risk analysis, data of L. monocytogenes and Salmonella spp. were not included in the model because of the low prevalence or absence of these organisms. The univariate analysis disclosed that the presence of VTEC and/or Campylobacter spp. in milk filters was associated with lack of cleanliness of bedding, water trough, and feed trough; nonevaluation of water hardness; lack of cleanliness of milk tank; and nonapplication of forestripping. After multivariate analysis, an association was observed with inadequate cleanliness of bedding and milk tank and the nonapplication of forestripping. PCR analysis of milk filters was a rapid and sensitive method for the microbiological evaluation of herd contamination status and should be included among the registration requirements for the authorization to produce and sell raw milk. Specific control actions must be incorporated into the farmer's daily practices to ensure the low-risk production of raw milk. [ABSTRACT FROM AUTHOR]

The direct sale by farmers of raw milk for human consumption has been allowed in Italy since 2004. The aim of this study was to evaluate the behaviour of selected foodborne pathogens in raw milk sold in vending machines, in field handling conditions, and during shelf-life from production to consumption. Temperature of storage of raw milk in 33 farms authorized to produce and sell raw milk were investigated from farm to vending machine delivery, together with consumer habits in one province of the Emilia-Romagna region of northern Italy. Failure to maintain appropriate low temperatures during shelf-life was recorded and 43% of consumers did not boil milk before consumption. Listeria monocytogenes, Escherichia coli O157:H7, Salmonella Typhimurium and Campylobacter jejuni strains were inoculated into raw milk samples, and the best (4°C as established by law) and worst temperature storage conditions detected (variable temperature) were simulated. Boiling tests were performed for each pathogen considered at high and low levels of contamination. Results showed an increase in L. monocytogenes in milk stored at 4°C and at variable temperatures recorded in shelf-life monitoring, an increase in E. coli O157:H7 and S. Typhimurium at variable temperatures but not at 4°C, and a decrease in C. jejuni in all storage conditions. Boiling milk is effective in making it safe for consumers. This study provides evidence that appropriate handling of raw milk, maintaining low temperatures, together with consumer education concerning boiling raw milk before consumption are key factors in preventing foodborne infections linked to raw milk consumption, and helps assess the risk of foodborne infection linked to raw milk consumption. [ABSTRACT FROM AUTHOR]

As reported on RASFF 's portal, in the first 9 months 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 35 days (5 weeks) 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 2 log CFU/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 66 days (about 9 weeks) no significant difference ( p > 0.05) was observed; whereas, a growth from 5.4 ± 0.4 to 7.1 ± 0.5 log CFU/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 (μ max , 1/h) of L. monocytogenes estimated ranged from 0.007 to 0.061. The square root model was used to predict the μ max at others temperature and to establish the time necessary to reach the European critical legal limit of 2 log CFU/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. [ABSTRACT FROM AUTHOR]

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 < 0.05) of the prevalence data was observed between data collected in two different regions of Northern Italy with an higher prevalence in Lombardy. In addition to the geographical area, the L. monocytogenes presence was influenced also by the seasonal period of collection samples, with peaks in spring and autumn. These results confirm the raw milk can be a source of foodborne illness outbreaks if consumed without sanitizing treatments, but the low prevalence and the low contamination levels (more than 80% of the contaminated samples contained <10 cfu ml −l of L. monocytogenes ) proving the hygienic quality of the milk produced in Northern Italy. [ABSTRACT FROM AUTHOR]

Trade of food of animal origin between countries is carried out according to specific bilateral agreements based on the Sanitary and Phytosanitary Measures (SPS) Agreement. As specific control plans are currently in place for establishments that produce meat products to be exported to the US in order to ensure the equivalence between control systems, the Italian Ministry of Health implemented a monitoring plan in food processing establishments that export meat (n = 29), fishery (n = 5) and dairy products (n = 16) to other Third Countries. Audits of good hygiene practices for the verification of Sanitation Standard Operating Procedures (SSOPs), were carried out. For each plant, 15 environmental samples for detection of Listeria monocytogenes (L. monocytogenes) and 5 samples of ready-to-eat products for detection of L. monocytogenes and Salmonella were taken, in a total of 750 surface samples and 250 food samples. The presence of L. monocytogenes was reported in 58 environmental samples (7.7%, 95% CI 6.0–9.9), detected in 50% of food companies. L. monocytogenes was also detected in 7 food product samples (2.8%, 95% CI 1.4–5.7). Salmonella spp. was never detected. Genetic characterization of L. monocytogenes strains with pulsed-field gel electrophoresis (PFGE) was made, in one case, to correlate the origin of product contaminations to the processing environment. Genetic homogeneity among strains isolated from the same establishment was always highlighted. Audits showed that the most part of features relating to the presence and application of SSOPs were satisfied in the large majority of food companies in a proportion ranging from 88% to 100%, except the rotation of disinfectants (44% not compliant) and the presence of a list of surfaces to be regularly checked (18% not compliant). This study allowed to collect information on the microbiological safety of food companies that export from Italy to the Third Countries. Microbiological contaminations were similar to food companies that export to the US, even if L. monocytogenes detection was slightly more common. Improving cleaning and disinfection procedures and the correct application of the SSOPs will be useful to comply with the zero tolerance for L. monocytogenes requested by some Third Countries. • Export of food of animal origin is carried out according to bilateral agreements. • Lab testing and SSOPs audits were carried out in export-authorized processing plants. • The presence and application of SSOPs were satisfactory in most food companies. • Microbiological contaminations were similar to food companies that export to US. [ABSTRACT FROM AUTHOR]

A model describing Listeria innocua evolution according to process parameters of 51 Italian salami processes and HPP in 31 companies was developed. A total of 51 challenge tests were performed. During processing a L. innocua reduction of 0.34–4.32 Log10 CFU/g was observed and HPP further reduced the count of 0.48–3.47 Log10 CFU/g; an overall reduction of 1.04–5.68 is reached. PH after acidification/drying process, a w after seasoning, duration of the seasoning and caliber resulted associated (p < 0.05) with L. innocua decrease. HPP efficacy was associated (p < 0.05) with a w and pH of the product: higher the pH and a w after the acidification/drying and seasoning phases, higher resulted the L. innocua reduction after HPP. No significant association was observed between L. innocua and salt, nitrate and starter content and other characteristics of process. The model meets companies and Authorities needs and represents a useful tool to predict L. monocytogenes lethality, giving recommendations to food business operators interested in exportation to the U.S. [ABSTRACT FROM AUTHOR]