Search

In the dairy industry, the late blowing defect in medium and long ripened cheeses causes important economic losses. This cheese defect, caused mainly by the anaerobic spore former Clostridium tyrobutyricum, is characterized by gas production resulting in holes formation in the paste, and in unpleasant aromas related to the butyrate production. Since longtime, the reference method used to detect the presence of total spore number in milk is the Most Probable Number (MPN), a semi-quantitative method which measures the bacterial growth and the gas production after heat treatment of the samples. This method often gives uncertain results, it requires long incubation periods and fails to differentiate between different species of spore-forming bacteria. A TaqMan real-time quantitative PCR targeting the phosphotransacetylase gene (pta) for C. tyrobutyricum was previously developed as an alternative technique to the traditional method, faster and more specific, and therefore of great interest to preventively determine the contamination of milk by C. tyrobutyricum. The aim of this work was the validation of this quantitative real-time PCR protocol for the C. tyrobutyricum detection in milk. Following the method validation, 120 samples of UHT and raw milk artificially contaminated with C. tyrobutyricum spores were analyzed in increasing concentrations, relating the results of the molecular method with those obtained by the MPN. Finally, 144 raw milk samples with a possible natural contamination were analyzed and demonstrated a positivity rate of 15.28% (CI95% 10.31–22.05%).

Italy has one of the highest incidence rates of foodborne botulism in Europe. It is a neuro-paralytic disease caused by ingesting ready-formed botulinum neurotoxins (BoNTs) produced by some spore-forming clostridia. Due to its severity and epidemic potential, foodborne botulism is included in the list of notifiable diseases, and botulism cases are managed based on collaboration among public health authorities providing food inspections, formal analysis, and supporting hospitals in rapid diagnosis. This study aimed to conduct a survey for investigating BoNT-producing clostridia occurrences in foods from Northern Italy between 2013 and 2020. In total, 2187 food samples were provided by food business operators for their own control protocols, and the presence of BoNT-producing clostridia was investigated using multiplex real-time PCR. Sixteen food samples (0.73%, 95% CI 0.45–1.19) were found positive for the presence of BoNT-producing clostridia, including dairy products, fruit, vegetables, sauces, bakery products, gastronomic preparations, meat products, and spices and flavourings, with the target genes bont/A and bont/B being the only targets found in this survey. Collaboration with local hospitals was carried out through analysis of biological samples in suspected foodborne botulism cases using a mouse bioassay for identifying the toxin involved. When available, food residues related to the suspected cases were also analysed. Among 52 patients with suspected symptoms of foodborne botulism, 18 patients were confirmed to be positive, showing the presence of BoNT/A, BoNT/B, and BoNT/E. In five cases, food residues were identified, mostly as homemade products. Our study highlights that foodborne botulism continues to be a public health concern in both industrial processing and homemade products, stressing the importance of consumer education to avoid hazardous botulism outbreaks.

In the three-years period 2012–2014, 160 cow milk samples from farms located in Lombardy and Emilia Romagna regions (Italy) were analyzed during the implementation of the Italian National Residues Monitoring Plan to assess the presence of PCDD/F, DL-PCB and NDL-PCB residues. The obtained contamination data were combined with cow milk consumption data from the Italian national dietary survey to estimate PCDD/F, DL-PCB and NDL-PCB human dietary exposure through the consumption of whole, semi skimmed and skimmed bovine milk. The exposure assessment was carried out separately for children, teenagers, adults and elderly. Average contamination levels of the analyzed samples were found to be 1.26 pg WHO-TEQ/g fat for the sum of PCDD/Fs and DL-PCBs and 9.30 ng/g fat for the sum of the 6 NDL-PCB indicators. PCB 126 was found to be the main contributor to the total WHO-TEQ. Using the upper bound approach, the estimated mean dietary intakes ranged from 0.07 pg WHO-TEQ/kg bw per day to 0.39 pg WHO-TEQ/kg bw per day for the sum of PCDD/Fs and DL-PCBs and considering exposure from whole milk. NDL-PCB mean dietary intakes resulted between 0.52 ng/kg bw per day and 2.86 ng/kg bw per day for consumption of whole milk. Children and teenagers were found to be the most exposed groups. This is the first time that Italian consumers exposure to NDL-PCBs is assessed using contamination data of cow milk produced in Italy.

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.

The FLOQSwabTM is a specimen collection device worldwide recognised for its superior performance in the clinical diagnostics. The aim of this work was to evaluate FLOQSwabTM for the recovery of microbiological samples from surfaces compared to the traditional swab (rayon tipped swab) as per ISO 18593:2004 standard. The FLOQSwabTM, thanks to its innovative manufacturing technology, allows improving the efficiency of recovery and release of analyte. The study has been divided into two experiments. In the first experiment the two swabs were evaluated for their capacity to recover and release the analyte (three different bacterial loads of Escherichia coli). In the second experiment, the two swabs were evaluated for their capacity to recover three different bacterial loads of E. coli from two different surface materials (stainless steel and polypropylene). In all experiments the flocked swab demonstrated a higher recovery rate compared to the traditional rayon tipped swab. The data obtained from this preliminary study demonstrated that the FLOQSwabTM could be a good food surfaces collection device, which improves the recovery of the analyte and thus produces accurate results. Based on the outcomes of the study, a larger field study is in progress using the FLOQSwabTM for samples collection to improve both environmental monitoring and the efficacy of the hygiene controls for food safety.

Quantitative microbial risk assessment (QMRA) models are extensively applied to inform management of a broad range of food safety risks. Inevitably, QMRA modeling involves an element of simplification of the biological process of interest. Two features that are frequently simplified or disregarded are the pathogenicity of multiple strains of a single pathogen and consumer behavior at the household level. In this study, we developed a QMRA model with a multiple-strain approach and a consumer phase module (CPM) based on uncertainty distributions fitted from field data. We modeled exposure to staphylococcal enterotoxin A in raw milk in Lombardy; a specific enterotoxin production module was thus included. The model is adaptable and could be used to assess the risk related to other pathogens in raw milk as well as other staphylococcal enterotoxins. The multiplestrain approach, implemented as a multinomial process, allowed the inclusion of variability and uncertainty with regard to pathogenicity at the bacterial level. Data from 301 questionnaires submitted to raw milk consumers were used to obtain uncertainty distributions for the CPM. The distributions were modeled to be easily updatable with further data or evidence. The sources of uncertainty due to the multiple-strain approach and the CPM were identified, and their impact on the output was assessed by comparing specific scenarios to the baseline. When the distributions reflecting the uncertainty in consumer behavior were fixed to the 95th percentile, the risk of exposure increased up to 160 times. This reflects the importance of taking into consideration the diversity of consumers' habits at the household level and the impact that the lack of knowledge about variables in the CPM can have on the final QMRA estimates. The multiple-strain approach lends itself to use in other food matrices besides raw milk and allows the model to better capture the complexity of the real world and to be capable of geographical specificity.

West Nile virus (WNV) is a recently re-emerged health problem in Europe. In Italy, an increasing number of outbreaks of West Nile disease, with occurrences of human cases, have been reported since 2008. This is particularly true in northern Italy, where entomological surveillance systems have been implemented at a regional level. The aim of this study was to use, for the first time, all the entomological data collected in the five regions undergoing surveillance for WNV in northern Italy to characterize the viral circulation (at a spatial and temporal scale), identify potential mosquito vectors, and specify relationships between virus circulation and meteorological conditions. In 2013, 286 sites covering the entire Pianura Padana area were monitored. A total of 757,461 mosquitoes were sampled. Of these, 562,079 were tested by real-time PCR in 9,268 pools, of which 180 (1.9%) were positive for WNV. The largest part of the detected WNV sequences belonged to lineage II, demonstrating that, unlike those in the past, the 2013 outbreak was mainly sustained by this WNV lineage. This surveillance also detected the Usutu virus, a WNV-related flavivirus, in 241 (2.6%) pools. The WNV surveillance systems precisely identified the area affected by the virus and detected the viral circulation approximately two weeks before the occurrence of onset of human cases. Ninety percent of the sampled mosquitoes were Culex pipiens, and 178/180 WNV-positive pools were composed of only this species, suggesting this mosquito is the main WNV vector in northern Italy. A significantly higher abundance of the vector was recorded in the WNV circulation area, which was characterized by warmer and less rainy conditions and greater evapotranspiration compared to the rest of the Pianura Padana, suggesting that areas exposed to these conditions are more suitable for WNV circulation. This observation highlights warmer and less rainy conditions as factors able to enhance WNV circulation and cause virus spillover outside the sylvatic cycle.

Long-chain n − 3 polyunsaturated fatty acids (PUFAs), particularly docosahexaenoic acid (DHA), have been shown to be essential during peri-natal growth and development of mammals. The study was conducted to determine whether the inclusion of fish oil in dairy goats diet during late gestation and early lactation would increase the proportion of n − 3 PUFAs in colostral and mature milk. From 3 weeks before kidding throughout 42 days of lactation, 14 dairy goats were fed either a control diet or a diet containing 1.1% fish oil (FO). Dietary treatment did not affect main components of colostrum, but lowered percentages of fat and lactose in mature milk. In colostrum, FO supplementation lowered the proportions of C18:0, C18:2, C18:3 and elevated those of C16:1 and very long-chain n − 3 PUFAs, mainly EPA (eicosapentaenoic acid) and DHA. In mature milk, FO supplementation lowered the proportion of C18:0 and raised C16:1 and n − 3 PUFAs (C18:3, EPA and DHA). Estimated transfer efficiencies for EPA and DHA into mature milk were 14 and 7%, respectively. Results suggest that goat's colostrum and milk can be enriched in n − 3 PUFAs by maternal dietary fish oil supplementation during late gestation and early lactation.

The aim of this work was to study the microbiological and physico-chemical changes throughout three cheesemaking replicates of Italian Formaggelle di capra cheese made from raw goat milk. Therefore, during the process, three samples of milk, curd and cheese at 3, 7, 11, 14, 21 and 30 days of ripening old cheese were taken from three cheesemaking replicates. The average of total mesophilic bacteria and Enterobacteriaceae count in raw milk was 5.27±0.57 and 3.8±1.02 Log cfu/mL, respectively. Lactic acid bacteria was the predominant bacterial group during the process, and they developed in different ways in each of the media used (M17 and MRS agar). Variability of microbial concentrations was observed between three cheesemaking replicates. A correlation between the presence of higher levels of Enterobacteriaceae in milk and the presence of other contaminants bacteria such as Escherichia coli β-glucuronidase-positive and coagulase-positive staphylococci was observed. In cheesemaking replicate n. 2, E. coli level was 5.07±0.03 Log cfu/mL and increased by about 1 log until the last week of ripening, when the level decreased to 5.69±0.2 Log cfu/mL. The milk used for the cheesemaking replicate n. 2 was found to be contaminated also by coagulase-positive staphylococci (3.18±0.06 Log cfu/mL), but the behaviour of this group appeared to be very variable. In this study a first step of process control and microbial groups study was performed and the cheesemaking process was registered in the website www.ars-alimentaria.it, the Italian site supported by the Italian Board of Health.

Consumption of raw or insufficiently cooked mussels contaminated with hepatitis A virus (HAV) is a major cause of infection to humans. The origin of mussels commonly used for the preparation of marinated seafood salads is often unknown, since different producers worldwide undergo a precooking treatment at the original collection site with methods and parameters not always indicated. These treatments could be insufficient for the inactivation of HAV, which is characterized by a high temperature resistance. Both high hydrostatic pressure (HHP) and marinade treatments have been shown to affect HAV vitality. In this study, two treatments (HHP and marinating) were combined in order to assess a potential synergistic effect on the virus vitality. A kinetic test was conducted by subjecting the experimentally-contaminated mussels (HAV titre: 10(6)/ml TCID50) to marinating, and to different HHP treatment (4,000; 5,000; and 6,000 bar for 1, 5, and 9 min). Virus post-treatment vitality was assessed by its ability to grow on cell cultures and by quantitative real-time RT-PCR to evaluate virus resistance under such conditions. Marinating treatment alone (final pH 4.3, and NaCl 2 %) did not inactivate the virus. On the other hand, the use of HHP treatment alone on non-marinated HAV-contaminated mussels was effective only above 5,000 bar for 5 min. The results of the present study elucidate the synergistic effect of a combination between marination and HHP treatments on the inactivation of the virus.

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 September 2011, an acute gastroenteritis outbreak affected 33 children in Northern Italy. Patients had drunk river water during an excursion. Identical GI.4 norovirus genomes were detected from one patient's stools and from the river water. Improper discharge of human sewage into the river may have caused this waterborne outbreak.

Ghidini, S., Zanardi, E., Conter, M., Varisco, G., Bolzoni, G. and Ianieri, A., 2007. Residues of aminoglycosides in milk: Confirmatory analysis. Veterinary Research Communications, 31(Suppl. 1), 365–367

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.

Due to the growing interest in organic products, a comparison between the chemical safety of organic and conventional products was undertaken. Milk and meat were the products chosen for study. The parameters evaluated to assess chemical safety were organochlorine pesticides, polychlorinated biphenyls (PCBs), lead, cadmium and mycotoxin contamination. Pesticides and PCBs residues in both organic and conventional milk and meat were lower than legal limits. Lead and cadmium residues were very low and did not differ between organic and conventional products. However, aflatoxin M1 contamination in some but not all samples of organic milk was significantly higher than those of conventional milk, although factors other than organic production might be implicated.

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.