Mammalian and avian species quantification in homogenized foods: real time PCR and digital PCR as tools for label compliance controls

Currently food fraud and authenticity of products composition are topics of great concern; ingredients quantification could allow to identify small amounts of contaminats or voluntary addition of improper components. Many molecular methods are available for species identification in foodstuffs but, for a better application, they should not be affected by the interference of other ingredients. The main purpose of this work was to verify the Real Time PCR and the Digital PCR (dPCR) quantification performances on baby food samples, specifically selected for their high miscibility to limit variability; chicken was selected as target to verify the performance of quantification of methods after having spiked the same quantity in different baby foods. The other aims were: (1) to verify a constant genome copies ratio existence between mammalian and avian species (2) to verify the dPCR performance, set up on housekeeping, to quantify mammalian and avian species in commercial products. Digital PCR showed fewer differences respect to Real Time PCR, at the same 15% w/w chicken spiking level. Despite the constant difference between mammalian and avian genome copies, in samples with the same spiking weight, the confidence intervals increasing towards the extreme values, made impossible to use genome copies ratio as a sort of correction factor between species. Finally, the dPCR system using the myostatin housekeeping gene to determine the chicken content seemed reliable to verify the labelling compliance in meat-based commercial products.

Investigation of Salmonella, hepatitis E virus (HEV) and viral indicators of fecal contamination in four Italian pig slaughterhouses, 2021-2022

In the pork production chain, the control at slaughterhouse aims to ensure safe food thanks to proper hygienic conditions during all steps of the slaughtering. Salmonella is one of the main foodborne pathogens in the EU causing a great number of human cases, and pigs also contribute to its spreading. Pig is the main reservoir of the zoonotic hepatitis E virus (HEV) that can be present in liver, bile, feces and even rarely in blood and muscle. The aim of this study was to assess the presence of both Salmonella and HEV in several points of the slaughtering chain, including pig trucks. Other viruses hosted in the gut flora of pigs and shed in feces were also assayed (porcine adenovirus PAdV, rotavirus, norovirus, and mammalian orthoreovirus MRV). Torque teno sus virus (TTSuV) present in both feces, liver and blood was also considered. Four Italian pig abattoirs were sampled in 12 critical points, 5 of which were the outer surface of carcasses before processing. HEV and rotavirus (RVA) were not detected. Norovirus was detected once. Salmonella was detected in two of the 4 abattoirs: in the two lairage pens, in the site of evisceration and on one carcass, indicating the presence of Salmonella if carcass is improper handled. The sampling sites positive for Salmonella were also positive for PAdV. MRV was detected in 10 swabs, from only two abattoirs, mainly in outer surface of carcasses. TTSuV was also detected in all abattoirs. Our study has revealed a diverse group of viruses, each serving as indicator of either fecal (NoV, RVA, PAdV, MRV) or blood contamination (TTSuV). TTSuV could be relevant as blood contamination indicators, crucial for viruses with a viremic stage, such as HEV. The simultaneous presence of PAdV with Salmonella is relevant, suggesting PAdV as a promising indicator for fecal contamination for both bacterial and viruses. In conclusion, even in the absence of HEV, the widespread presence of Salmonella at various points in the chain, underscores the need for vigilant monitoring and mitigation strategies which could be achieved by testing not only bacteria indicators as expected by current regulation, but also some viruses (PAdV, TTSuV, MRV) which could represent other sources of fecal contamination.

A Review of Slaughter Practices and Their Effectiveness to Control Microbial - esp. Salmonella spp. - Contamination of Pig Carcasses

The BIOPIGEE project (part of the One Health European Joint Programme under Horizon 2020) aimed to identify relevant measures to effectively control Salmonella, and another zoonotic pathogen, hepatitis E virus (HEV) within the pig meat food chain. The aim of this study was to identify biosecurity measures or management practices that are relevant for limiting Salmonella and/or HEV occurrence and spread within pig slaughterhouses. This was with the final goal of compiling a list of biosecurity measures for different processes and operations along the slaughter line with evidence of their effectiveness. To achieve this, a literature review was conducted on studies estimating the effectiveness of measures applied in slaughterhouses to reduce the microbial contamination of pig carcasses. Results of this literature search are discussed and presented in summary tables that could be used as a source of information for the pig slaughter industry to further develop their guidelines on hygienic slaughter.

Assessing pig farm biosecurity measures for the control of Salmonella on European farms

Salmonella spp. is a common zoonotic pathogen, causing gastrointestinal infections in people. Pigs and pig meat are a major source of infection. Although farm biosecurity is believed to be important for controlling Salmonella transmission, robust evidence is lacking on which measures are most effective. This study enrolled 250 pig farms across nine European countries. From each farm, 20 pooled faecal samples (or similar information) were collected and analysed for Salmonella presence. Based on the proportion of positive results, farms were categorised as at higher or lower Salmonella risk, and associations with variables from a comprehensive questionnaire investigated. Multivariable analysis indicated that farms were less likely to be in the higher-risk category if they had '<400 sows'; used rodent baits close to pig enclosures; isolated stay-behind (sick) pigs; did not answer that the hygiene lock/ anteroom was easy to clean; did not have a full perimeter fence; did apply downtime of at least 3 days between farrowing batches; and had fully slatted flooring in all fattener buildings. A principal components analysis assessed the sources of variation between farms, and correlation between variables. The study results suggest simple control measures that could be prioritised on European pig farms to control Salmonella.

Cross-sectional study of hepatitis E virus (HEV) circulation in Italian pig farms

Foodborne transmission is considered the main way of spreading zoonotic hepatitis E virus (HEV) infection in Europe. In recent years, the human cases of hepatitis E in subjects without history of travel in endemic areas have raised, suggesting that domestic HEV transmission is increasing. Pork products with or without liver, are often indicated as the source of many human foodborne HEV cases as well as small outbreaks. Pigs are recognized as the main reservoir of the zoonotic HEV-3 genotype, the most frequently detected in human cases in the EU. In the absence of a harmonized surveillance of HEV circulation, data on prevalence are heterogeneous but confirm a widespread circulation of HEV-3 in pig herds across EU. HEV-3 can pass through the food chain from farm to fork when infected animals are slaughtered. In Italy, several studies reported the circulation of HEV-3 in pig farms, but results are heterogeneous due to different methodologies applied. In the present study, we performed a survey over 51 pig herds belonging to three main types of farms: breeding, fattening and farrow-to-finish. HEV-RNA was analyzed by broad range Real-time RT-PCR on 20 samples for each farm, obtained by pooling together feces from 10 individuals. Overall, HEV RNA was confirmed on 150 fecal pooled samples out of 1,032 (14.5%). At least one positive pooled sample was detected from 18 farms out of 51 tested (35.3%). By lowering the number of infected pigs at primary production, the risk of HEV-3 entering into the food chain can be reduced. Hence, information on HEV circulation in herds is highly relevant for choosing preventive measures and deserves development of a monitoring program and further investigations.

Gluten quantification in gluten-free food for celiac people in Lombardy and Emilia Romagna - Italy

Background

In recent decades, the celiac disease showed a gradual increase in prevalence. Therefore, there was a raised demand of gluten-free products. EU Reg. 1169/2011 states that 20 mg.kg-1 (ppm) is the maximum gluten content in food for celiac people, and that “gluten-free” labelling must be put on compliant food packages. This work is a study on different food categories, aiming at verifying the safety of analyzed samples.

Methods

Totally, 4615 gluten-free-labelled specimens were collected from January 2019 to April 2022 (pasta, 2944; cured meat, 566; flours/bakery, 489; sweets, 125 and other matrices, 491). A commercially available E.L.I.S.A. kit, according to the AOAC 2012.01-2016 method, was used to quantify gluten.

Results

In 97% of samples (4475) the gluten content was &lt;5 ppm (lower LOD), and in 2.4% (112) it was between 5 ppm and &lt;20 ppm. In the remaining 0.6% (28), the gluten concentration was ≥20 ppm. Of these, 0.32% (15) were between 20 and &lt;80 ppm (upper LOD), and 0.28% (13) ≥80 ppm.

Conclusions

The increased prevalence of celiac disease and the consumers’ perception that a gluten-free diet gives benefits, lead to a greater demand of gluten-free products. In this study, 99.4% of samples were compliant with the gluten-free labelling and safe for celiac consumers. The 0.32% had a gluten content between 20 and 80 ppm, still considered “compliant”, according to the EU Reg. 828/2014 that defines as very low gluten containing (thus edible for some celiac groups), those products with a gluten content &lt;100 ppm. Only 0.28% of samples was non-compliant (≥80 ppm). However, the authors accounted irregular those foods with ≥20 ppm. Considering the importance of these products in the daily diet, and the increasing probability to get sick by individuals, the study of their compliance to the law limits results to be important.

Key messages

• A continuous surveillance of gluten-free-labelled food products is very important to prevent risks for celiac consumers.

• The foodstuffs distributed in the two considered regions are mainly safe for celiac patients.

Detection of Hepatitis A Virus and Norovirus in Different Food Categories: A 6-Year Survey in Italy

To observe the prevalence of contamination by hepatitis A virus (HAV) and norovirus (NoV) in different food types, 9242 samples were analyzed over a 6-year period (January 2014-December 2019). Samples were from routine official activities by Competent Authorities (CAs) and Food Business Operators, according to Hazard Analysis and Critical Control Points plans. Analyses were performed in accordance with European and Italian regulations. Food types were obtained from different production areas of Italy, and ranged from mollusks, ready-to-eat (RTE) and packaged vegetables, frozen berries, tap water, fruit and RTE fruit salads, and processed and preserved foods. No risk management plans were set by the authors' laboratory, because they were still adopted by conferring customers. Analyses were conducted according to ISO/TS 15216-2:2013 (ISO in Part 2: Method for Qualitative Detection. International Organization for Standardization, Geneva, 2013). The data showed that 2.25% (95% CI: 2.0-2.6) of samples were contaminated by at least one virus type, and that the most detected pathogen was NoV GII (89.50% of all positives). Mollusks (filter-feeding animals) were the most contaminated category (92.31% of all positives) not only by NoV or HAV individually, but also by multiple HAV/NoV contaminations consisting of 22.59% of all positives. For NoV, there was a significant correlation between shellfish positivity and season, with the autumn-winter period being the most associated with risk. Conversely, berries, drinking water and RTE vegetables, previously linked to several outbreaks, showed a low rate of contamination. These results from data collection have implications for the improvement of sampling plans for HAV and NoV by Italian CAs, and by food-producing and distribution operators. Moreover, these findings obtained by a standardized qualitative method contribute the collection of data aimed at establishing new microbiological criteria not yet foreseen (but advocated) by current European rules.

Torque Teno Sus Virus (TTSuV) Prevalence in Wild Fauna of Northern Italy

Torque teno sus virus (TTSuV) is a non-enveloped circular ssDNA virus which frequently infects swine and has been associated with hepatic, respiratory, and autoimmune disorders. TTSuV’s pathogenic role is still uncertain, and clear data in the literature on virus reservoirs are lacking. The aims of this study were to investigate the presence of potentially zoonotic TTSuV in wild animals in Northern Italy and to evaluate their role as reservoirs. Liver samples were collected between 2016 and 2020 during four hunting seasons from wild boars (Sus scrofa), red deer (Cervus elaphus), roe deer (Capreolus capreolus), and chamois (Rupicapra rupicapra). Samples originated from areas in Northern Italy characterized by different traits, i.e., mountains and flatland with, respectively low and high farm density and anthropization. Viral identification was carried out by end-point PCR with specific primers for TTSuV1a and TTSuVk2a species. TTSuV prevalence in wild boars was higher in the mountains than in the flatland (prevalence of 6.2% and 2.3%, respectively). In wild ruminants only TTSuVk2a was detected (with a prevalence of 9.4%). Our findings shed light on the occurrence and distribution of TTSuV in some wild animal species, investigating their possible role as reservoirs.

Monitoring of SARS-CoV 2 on primary production and manually processed foods in Northern Italy

Background

SARS CoV2 pandemic has generated interest in research of virus spread sources, apart from human contagion. In particular different studies are performed to understand surfaces involvement; during the epidemic event, different types of studies on surfaces have been performed. However, there is little information regarding the presence of the virus in food; wastewater contamination and poor hygiene practices could be the sources of viral contamination in handled food products. The aim of this work was to analyze different types of food for Sars CoV 2 presence.

Methods

390 samples of molluscs, 353 vegetables, 10 meat, 72 water, 169 berries, 16 seafood products and ready-to-eat dishes were analysed (2020-2021). Samples were selected from those provided for routine analysis during the pandemic period. The preparation was done based on ISO 15216-2 indications, followed by extraction with Nuclisense®Minimag® system; real-time PCR was applied to detect the Sars CoV2 virus Open Reading Frame 1ab, with two different master mixes.

Results

All samples tested were negative for ORF1ab detection. Many hypothesis can be made about negative Results: it could be possible that contamination levels in water, or on surfaces in contact with food, are too low to generate a detection signal; again, handling practices may be sufficient to avoid the transmission of the virus to food. Otherwise, the selected genetic target and the Real-time PCR performed, could have been not so efficient in detecting virus as expected.

Conclusions

In this preliminary work, food does not seem to be a substrate for Sars CoV2 contamination; other food categories or transformation/production processes could be investigated to confirm the obtained results. Also, different targets and amplification systems would have to be evaluated to verify the rule of foodstuffs as Sars CoV2 vehicles.

Key messages

Primary production and manual processed food don't seem to be at risk for SARS CoV2 contamination. Food has not been identified as a source of Sars CoV2 spreading.

Hepatitis E Virus (HEV) Spread and Genetic Diversity in Game Animals in Northern Italy

Hepatitis E virus (HEV) is the causative agent of hepatitis E, an emerging public health infection which has an increasing incidence across Europe. Because of the apparent lack of species barriers, HEV was characterized as a zoonotic agent. Swine are recognized as the main reservoir, but HEV is also found in wild animals such as ungulates, lagomorphs, and bats. Our work aimed at detecting the HEV presence in wild fauna in two hunting areas of Northern Italy (Parma and Sondrio areas) with different environmental and anthropic characteristics to investigate its possible role as reservoir. Liver samples were collected from wild boars, red deer, roe deer and chamois, and viral identification was carried out by One-Step RT Real-time PCR. Positive samples were genotyped, and phylogenetic analysis was performed. The virus was found only in the wild boar population, with different prevalence and subtypes in the two areas (14% HEV3a and 1.2% close to HEV3f in Parma and Sondrio, respectively). Wild ruminants seem otherwise to pose a marginal risk. Given the high pig farm density in the Parma area, and expansion of the wild boar population, continuous monitoring of the strains circulating in wildlife is crucial.

Geographical restriction of Hepatitis E virus circulation in wild boars (Sus scrofa) in Emilia-Romagna region, Northern Italy

Hepatitis E virus (HEV) is a singlestrand RNA virus that causes an acute viral hepatitis in humans. Among its eight recognized genotypes, HEV-3 and HEV-4 are zoonotic, infecting humans, pigs and wild boars. Recently, HEV-3 has been also detected in red deer, which represents another reservoir of HEV. Consumption of raw pork products (mainly liver sausages), undercooked wild boar meat, raw wild boar liver and deer meat has been responsible for foodborne HEV human worldwide. From November 2018 to March 2019, liver samples collected from 97 wild boars hunted in Emilia-Romagna region (Northern Italy) were tested for HEV RNA. The hunting area included two territories for an extension of 33 km2, named A (about 13 km2,natural park, deciduous wood) and B (about 20 km2, cultivated fields in proximity of a river) areas. Distance between the two areas ranged between 8 to 10 km. A total of 73 wild boars were hunted in area A, and 24 in area B. HEV RNA was detected by Real-time RT- PCR in 23/73 liver samples of wild boars living in area A only (31.5% - 95% CI: 22.0-42.8%). The HEV sequences (n=13) clustered within genotype 3. The majority of positives belonged to animals < 12 months (12/25; 48%), followed by subadults (13-24 months) (7/16; 43.8%) and adults (4/32; 12.5%). This difference was found to be statistically significant (p=0.0024). In absence of pig farms, the restriction of HEV-positive animals to a well-defined territory of 13 km2 (Boschi di Carrega Regional Park) could hypothetically be related to the presence of red deer (Cervus elaphus), which lived in area A at the beginning of the hunting season. Further studies are needed to confirm or deny our hypothesis.

Evaluation of Norovirus contamination in bivalve molluscs harvested from Northern Adriatic Sea, Italy

Background

Norovirus (NoV) is the leading cause of acute gastroenteritis in developed countries. Transmission is through direct contact, unsanitary food handling or ingestion of contaminated water or food. Shellfish bioaccumulate NoV and current post-harvest depuration is not effective for its removal.

Materials and

Methods

A monitoring programme for NoV in bivalve shellfish harvested from Northern Adriatic Sea was initiated in 2016. From January 2016 to March 2019, 418 samples including 257 Manila clams, 73 mussels, 46 striped clams, and 42 oysters, were examined. Mollusc samples were tested for NoV genogroups I (NoV GI) and II (NoV GII) contamination by RealTime RT-PCR according to ISO 15216-2.

Results

Ninety-three out of 418 tested samples (22.2%) were contaminated by at least one NoV genogroup, the simultaneous presence of the two genogroups was detected in 19/418 of the cases. Positive samples were distributed among the tested species as follow: 29/73 (39.7%) mussels, 51/257 (19.5%) Manila clams, 8/42 (19.0%) oysters, 5/46 (10.9%) striped clam. In 2016 (n = 135), 2017 (n = 122), 2018 (n = 132) and in the first trimester of 2019 (n = 12), prevalence of NoV was 6.7%, 24.6%, 31.8% and 41.4%, respectively. NoV GII was largely predominant being detected, alone or in association with GI, in 98.9% of the contaminated samples. On the other hand, GI prevalence increased from 1.5% (2016) to 12.1% in 2018, maybe reflecting a higher circulation of this genogroup in production environments.

The vast majority of positive samples (91.4%) were detected during the cold season (November to March).

Conclusions

Overall positive samples have increased over the years (from 6.7% in 2016 to 31.8% in 2018). NoV GII was the most frequently detected genogroup, but NoV GI prevalence significantly raised in 2018. The routine application of quantitative RT-PCR (ISO 15216-1) to determine the viral load in bivalve molluscs would expand knowledge on potential for foodborne transmission.

Key messages

Overall positive samples have increased over the years. The routine application of quantitative PCR to determine the viral load in bivalve molluscs would expand knowledge on potential for foodborne transmission.

Contamination of Poultry Meat with Salmonella infantis should be considered a Risk for Food Safety?

Issue/problem

EU Regulation regarding fresh poultry meat considers only S. enteritidis or S. typhimurium as Food Safety Criteria. On the contrary, the isolation of other Salmonella spp. in this food matrices is considered compliant. Several bibliographical sources indicate an increase in the isolation trend of S. infantis in the poultry industry and in derived products.

Description of the problem

Episodes of food poisoning caused by fresh chicken meat contaminated with S. infantis have been recently reported. According to CDC, last year in USA, an outbreak caused by a S. infantis strain, resistant to multiple antibiotics, ended with 129 sick people, 25 hospitalizations and a death. National Salmonellosis Control Plan for Poultry 2019-21 establishes in Italy the abatement conditions for poultry farms in case of positive isolation of S. enteritidis, S. typhimurium and S. infantis.

Results

In 2018, the National Health System disposed the analysis of batches of fresh chicken meat from Poland, sampled in a cold storage facility in Northern Italy. Food Control Dept. of IZSLER analysed 156 samples for a total of 780 sampling units (s.u.), for Salmonella spp.: 72 samples were positive (46,15%;corresponding to 222 s.u. - 28,46%). 42 strains were serotyped as S. enteritidis, 149 as S. infantis, 26 as S. newport, 4 as S. kentucky and 1 as S. mbandaka. According to EU Regulation, batches positive for S. enteritidis were indicated as not compliant, but batches positive to other Salmonella were considered regular.

Lessons

EU legislation allows the circulation of chicken meat contaminated with S. infantis. Chicken meat should be consumed after appropriate well cooking eliminating this hazard, but it does not protect the consumer from the risk of cross-contamination of tools and surfaces at the household level. It’s therefore fundamental the application of correct processing practices in order to prevent the spreading of Salmonella in home kitchens and limit dangerous episodes of infection.

Key messages

S. infantis trend of isolation in the poultry industry is increasing. application of GMPs in home cooking is fundamental to limit food outbreaks of infection.

Antiviral Activity of Essential Oils Against Hepatitis A Virus in Soft Fruits

Berries have repeatedly been associated with outbreaks of hepatitis A virus (HAV) infection. The fruits are usually minimally processed in the food industry due to their delicate nature. While washing treatments partially remove enteric viruses, the commonly used chemical additives produce toxic by-products. A valid alternative to preserve the food safety of these products could be the use of essential oils (EOs). EOs exert antimicrobial activity and do not interfere with the nutritional characteristics of food products. We investigated the efficacy of four essential oils, lemon (Citrus limon), sweet orange (Citrus sinensis), grapefruit (Citrus paradisi), and rosemary cineole (Rosmarinus officinalis chemotype 1.8 cineole) in reducing viral loads of HAV in soft fruits. Mixed fruit berries were inoculated with 10^6.74 TCID₅₀/ml of HAV, and treated with four different EOs (0.5% lemon, 0.1% sweet orange and grapefruit, and 0.05% rosemary) for 1 h at room temperature. Virus infectivity was then assessed by titration assays for its ability to grow on cell cultures. A statistically significant reduction in HAV titer on the fruit surface was observed after treating the berries with EOs of lemon (2.84 log TCID₅₀/ml), grapefruit (2.89 log TCID₅₀/ml), and rosemary cineole (2.94 log TCID₅₀/ml). Rosemary cineole was the most effective EO in reducing viral titer on berries, followed by grapefruit EO. These results improve our knowledge about the antiviral activity of these EOs and highlight their potential use in fresh produce sanitation.

A large prolonged outbreak of hepatitis A associated with consumption of frozen berries, Italy, 2013-14

PURPOSE

In 2013/2014, Italy experienced one of the largest community-wide prolonged outbreaks of hepatitis A virus (HAV) throughout the country. The article provides a comprehensive description of the outbreak and the investigation carried out by a multidisciplinary National Task Force, in collaboration with regional and local public health authorities. Control strategies of food-borne HAV infection in both the human and food sectors are also described.

METHODOLOGY

Enhanced human epidemiological and microbiological surveillance together with microbiological monitoring of HAV in food and trace-back investigation were conducted.

RESULTS

A total of 1803 HAV cases were identified from 1 January 2013 to 31 August 2014, in Italy. Sequencing was possible for 368 cases (20.4 %), mostly collected between 1 January 2013 and 28 February 2014, and 246 cases (66.8 %) harboured an HAV outbreak strain. Imported frozen berries contaminated with HAV were identified as the vehicle of the outbreak which also involved many other European countries in 2013 and 2014. Epidemiological evidence obtained through a case-control study was supported by the finding of a 100 % nucleotide similarity of the VP1/2A sequences of HAVs detected in human and food samples. Trace-back investigation revealed an extremely complex supplying network with no possibility for a point source potentially explaining the vast contamination of berries found in Italy.

CONCLUSION

The investigation benefited from an excellent collaboration among different sectors who shared proactively the available information. Our findings highlight the importance of considering frozen berries among the highest risk factors for HAV.

Occurrence of hepatitis A and E and norovirus GI and GII in ready-to-eat vegetables in Italy

Fresh vegetables and their ready-to-eat (RTE) salads have become increasingly recognized as potential vehicles for foodborne diseases. The EU Reg. 1441/2007 establishes microbiological criteria for bacterial pathogens for products placed on the market during their shelf-life (i.e. Salmonella spp., Listeria monocytogenes) for pre-cut fruits and vegetables (RTE) whilst it does not address the problem of contamination by enteric viruses. In this study we investigated the contamination by hepatitis A virus (HAV), hepatitis E virus (HEV) and norovirus (NoV) in 911 ready-to-eat vegetable samples taken from products at retail in Apulia and in Lombardia. The vegetable samples were tested using validated real-time PCR (RT-qPCR) assays, ISO standardized virological methods and ISO culturing methods for bacteriological analysis. The total prevalence of HAV and HEV was 1.9% (18/911) and 0.6% (6/911), respectively. None of the samples analysed in this study was positive for NoV, Salmonella spp. or Listeria monocytogenes. The detection of HAV and HEV in RTE salads highlights a risk to consumers and the need to improve production hygiene. Appropriate implementation of hygiene procedures is required at all the steps of the RTE vegetable production chain and this should include monitoring of emerging viral pathogens.

Key Role of Sequencing to Trace Hepatitis A Viruses Circulating in Italy During a Large Multi-Country European Foodborne Outbreak in 2013

Background

Foodborne Hepatitis A Virus (HAV) outbreaks are being recognized as an emerging public health problem in industrialized countries. In 2013 three foodborne HAV outbreaks occurred in Europe and one in USA. During the largest of the three European outbreaks, most cases occurred in Italy (>1,200 cases as of March 31, 2014). A national Task Force was established at the beginning of the outbreak by the Ministry of Health. Mixed frozen berries were early demonstrated to be the source of infection by the identity of viral sequences in patients and in food. In the present study the molecular characterization of HAV isolates from 355 Italian cases is reported.

Methods

Molecular characterization was carried out by PCR/sequencing (VP1/2A region), comparison with reference strains and phylogenetic analysis.

Results

A unique strain was responsible for most characterized cases (235/355, 66.1%). Molecular data had a key role in tracing this outbreak, allowing 110 out of the 235 outbreak cases (46.8%) to be recognized in absence of any other link. The data also showed background circulation of further unrelated strains, both autochthonous and travel related, whose sequence comparison highlighted minor outbreaks and small clusters, most of them unrecognized on the basis of epidemiological data. Phylogenetic analysis showed most isolates from travel related cases clustering with reference strains originating from the same geographical area of travel.

Conclusions

In conclusion, the study documents, in a real outbreak context, the crucial role of molecular analysis in investigating an old but re-emerging pathogen. Improving the molecular knowledge of HAV strains, both autochthonous and circulating in countries from which potentially contaminated foods are imported, will become increasingly important to control outbreaks by supporting trace back activities, aiming to identify the geographical source(s) of contaminated food, as well as public health interventions.

[60]Fullerene–porphyrin [n]pseudorotaxanes: self-assembly, photophysics and third-order NLO response

Herein we report a series of porphyrin and methano[60]fullerene that undergo self-assembly.

Detection and Molecular Characterisation of Swine Hepatitis E Virus in Brescia Province, Italy

Hepatitis E virus (HEV) is an important public health concern in many developing countries and it occurs in sporadic forms in industrialized areas. With the discovery of swine HEV in pigs, which is genetically closely related to human HEV, hepatitis E is considered to be a zoonotic disease. To investigate the circulation of HEV within a distinct area of Lombardy region (Northern Italy), 17 pig farms were subjected to monitoring study by collection of fresh stool samples each represented by ground-pooled specimens. In particular, three distinct types of breeding farms were focused, represented by farrow to weaning, farrow to finish and fattening farms, respectively. Epidemiological data confirm that in Europe the seroprevalence in pigs, more than 9 month of age, ranges from 51.4 to 75%, while in 3-9 months fatteners is about 38%. In France and Italy, the positivity among farms is respectively 30 and 97.4% and the seroprevalence in Italy is 50.2%. Since HEV viremia was typically observed in the early period of life in swine, faeces were collected in boxes containing weaning pigs. For the study, 183 stool samples were collected and amplifications were performed with universal primers specific for the ORF2 region of genome. Twentyeight samples resulted positive to HEV RNA and genotyping demonstrated that they were closely related to HEV strains belonging to genotype 3 and circulating in Europe. Comparison with reference strains from GenBank excluded their similarity to genotype 1, 2 or 4 confirming that genotype 3 strains are circulating in Europe. Since it was demonstrated that swine act as a reservoir for HEV, and since many strains into HEV genotype 3 share a strong molecular similarity to human HEV, it was important to detect the presence of HEV in a restricted area with a very high density of pigs.

Synergistic effect of high hydrostatic pressure (HHP) and marination treatment on the inactivation of hepatitis a virus in mussels (Mytilus galloprovincialis)

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.

Waterborne norovirus outbreak during a summer excursion in Northern Italy

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.

Isolation and genomic sequence of hepatitis A virus from mixed frozen berries in Italy

Hepatitis A virus (HAV) was detected in two samples of mixed frozen berries linked to Italian hepatitis A outbreak in April and September 2013. Both viruses were fully sequenced by next-generation sequencing and the genomes clustered with HAV complete genomes of sub-genotype IA with nucleotide identities of 95-97%.

Reduction of Escherichia Coli O157:H7 During Manufacture and Ripening of Italian Semi-Dry Salami

In order to simulate a contamination at the processing plant, one batch of freshly-processed 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 a_w ). 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.

Study of Growth Potential of Listeria Monocytogenes in Low Fat Salami: An Innovative Italian Meat Product

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.

Hepatitis E virus in wild boar in the central northern part of Italy

Hepatitis E virus (HEV) is responsible for sporadic acute hepatitis in developed countries, where the infection is acquired probably through ingestion of contaminated food, in addition to travel-related cases. In this study, the circulation of HEV in wild boar from nine Italian provinces was evaluated. An overall seroprevalence of 10.2% was found, although there were differences among the provinces, while no samples were positive for HEV RNA detection. This study indicates an active circulation of HEV in the Italian wild boar populations and suggests to consider the zoonotic risk in handling and eating meat from this animal.

Listeria monocytogenes in Ready-to-Eat Seafood and Potential Hazards for the Consumers

The risk of exposure to Listeria monocytogenes (L. monocytogenes) when consuming Ready-to-Eat (RTE) seafood was assessed in the Veneto Region (Italy). Thirty-eight samples were analyzed, each sample consisted of three subunits belonging to the same batches. The first of the three units was examined immediately, the second was stored at +4°C (for all of its shelf-life) and the third at +10°C (for the latter third of its shelf-life) before the analysis. Chemical-physical and microbiological parameters were tested simultaneously. Culture results showed the presence of viable L. monocytogenes in 9 (23,68%) of the 38 samples analysed, 3 (33,33%) of which with a concentration >100 cfu/g. PCR tests yielded 12 L. monocytogenes positive samples. Semipreserves with aw (water activity) and pH values that favour L. monocytogenes growth were the only ones to result positive to microbiological and PCR tests. Temperature proved to be an important factor as it limits the growth of L. monocytogenes, including products with potentially high competitive microbial charges. Four different serotypes were recovered and ribotyping has helped to highlight the genomic variability of L. monocytogenes strains in food. This supports the hypothesis that L. monocytogenes continues to evolve genetically to the detriment of phenotypic conservation.

Assessment of human enteric viruses in shellfish from the northern Adriatic sea

Incidence and circulation of different strains of hepatitis A and Norovirus in shellfish were studied on 235 samples (Tapes philippinarum, Mytilus galloprovincialis, Ostrea spp. and Chlamys spp.) obtained from different sites, representing the shellfish production areas of the northern Adriatic sea. Shellfish were harvested in the period of one year and, after depuration, were examined for bacterial (Escherichia coli and Salmonella) and viral (HAV and NoV) contamination. Viral contamination was present on average in 22% of samples: specifically, 6% of samples tested positive for HAV, 14% for NoV and 2% for both viruses. None of the samples revealed the presence of Salmonella, and in most of them (93%) the number of E. coli was below the European legislation limit of 230 MPN/100 g. T. philippinarum was the species most often contaminated, as well as being the only species in which the legal limit for E. coli was, in some cases, exceeded. Both HAV and NoV contamination were detected throughout the year; NoV detection was slightly more frequent during winter months, but positive samples were also present in summer. The sequencing of the PCR products showed the circulation of only one HAV genotype (IA) and four different NoV genotypes (Hawaii, Melksham, Lordsdale and GGIIb) with a prevalence of the GGIIb genotype in the second period of the monitoring.

[Integrate cell culture--PCR (ICC/PCR) in viruses researches in environmental and food samples. Note I]

We carried out an experimental work integrating cell-culture and PCR to follow the HAV replication, to verify the PCR positiveness times and to confirm infectious viral particles presence. In tests HAV strain H59-175 was used. We proceeded to an initial valuation of the lowest viral concentration detectable by PCR. With viral titres between 10(5)-10(7) PFU/ml, the highest positive dilution resulted 10(-4)-10(-5). Then the 1 log lower dilution was inoculated in cell culture. At fixed times we proceeded to take surnatant and lisate samples for PCR test. After cell culture integration, positiveness was obtained in 72-120 hours against the 10-18 days necessary for CPE appearance.

[Set up of in vitro methods able to detect the safety of astringent liquids]

AIM

Most of dental operators agree about a gengival retraction impregnated cord in order to obtain an accurate and overwide dental impression. Hemostatic agents allow the formation of the primary coagulum that determines/causes the retraction of gum connective. Sometimes these astringent liquids cause local inflammation reaction as reported in literature. Aim of this work was the evaluation of the cytotoxic and inflammatory action of the most common astringent liquid on human gum primary cells by in vitro tests.

METHODS

For this purpose primary cultures of normal human oral keratinocytes were established, following used either as monolayer or as reconstituted model. All dental preparations were dissolved in CEC medium, diluted to the designed concentrations and applied to the cultured cells. The cytotoxicity was determined by using MTT test, able to evaluate the succinate dehydrogenase activity and therefore the cell viability. Control cultures were treated with CED alone, whereas sodium dodecyl sulphate (SDS) was used as a positive control. Furthermore, the inflammatory response, determined by measuring TNF-alpha and IFN-gamma release, was evaluated on a reconstituted multilayer human oral epidermis model.

RESULTS

All agents tested showed a dose-dependent increase in the cytotoxicity to normal human gingival keratinocytes over the dose range examined. In particular the results obtained suggest the higher toxicity of the Astringedent X compound.

CONCLUSION

The results obtained from the present studies not only provide useful estimates of relative toxicities of these preparations to human oral mucose, but also can be useful as a standard for cytotoxic and inflammatory assessment of newly developed dental preparations to be topically applied to the oral mucosa. It is important to note, however, that the interpolation of these findings to in vivo conditions remains to be done.

Evaluation of the protective effects of alpha-tocopherol and retinol against ochratoxin A cytotoxicity

Ochratoxin A (OTA), a mycotoxin frequently present in food and feedstuffs, produces a wide range of toxic effects, including cell death via lipid peroxidation. In one human and four animal cell lines we determined the half lethal concentration (LC50) of OTA, its effect on reactive oxygen species (ROS) production, and its ability to induce cytochrome p450 activity. We also examined the protective effect of alpha-tocopherol and all-trans-retinol in the most sensitive cell lines (i.e. bovine mammary epithelia, for which LC50 was 0.8 microg/ml (24 h), and Madin Darby canine kidney, for which LC50 was 4.3 microg/ml (48 h)). Pre-incubation for 3 h with either antioxidant significantly (P<0.05) ameliorated the OTA-induced reduction in cell viability and significantly decreased (P<0.05) ROS production. These findings indicate that oxidative stress is an important factor in OTA cytotoxicity. Supplementation with antioxidant molecules may counteract the short-term toxicity of this mycotoxin.

[Role of the Istituti Zooprofilattici Sperimentali in controlling the microbiological and toxicologic risks related to seafood]

The "Istituti Zooprofilattici" are an important network whose main function is the monitoring of animal health as well as food. As a result of the recent improvements in aquaculture technology interest in the safety of seafood is increasing. Therefore, the purpose of this study was to set up diagnostic methods for the detection of virus contamination, as well as the use of in vitro techniques able to identify the different toxins. The results have allowed the development of molecular biology assays which, together with the isolation in cell cultures, can detect contaminations/infections by the hepatitis A virus and the most common enteroviruses. Moreover, specific selected cell lines have led to the detection of different toxins. These laboratory methods will be used in order to control seafood safety.

In vitro comparison of the antimycotic activity of a miconazole-HP-beta-cyclodextrin solution with a miconazole surfactant solution

The antimycotic activity of a new parenteral solution containing miconazole was compared with that of a marketed solution (Daktarin IV solution). This solution has been withdrawn from the Belgian market, probably because of toxic effects related to the presence of polyoxyl 35 castor oil. We propose a new formulation containing miconazole (10 mg/mL) (like the marketed solution), in combination with hydroxypropyl-beta-cyclodextrin and lactic acid. The MICs of these two solutions were determined by a broth microdilution method (based on NCCLS guidelines) for 67 yeasts and 50 filamentous fungi isolates. This study shows that the MICs obtained with these two solutions are not significantly different.