49 research outputs found
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
Geographical restriction of Hepatitis E virus circulation in wild boars (Sus scrofa) in Emilia-Romagna region, Northern Italy
Hepatitis E virus (HEV) is a single‐strand 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 feral pigs. 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
Identification of a panel of tumor-associated antigens from breast carcinoma cell lines, solid tumors and testis cDNA libraries displayed on lambda phage
BACKGROUND: Tumor-associated antigens recognized by humoral effectors of the immune system are a very attractive target for human cancer diagnostics and therapy. Recent advances in molecular techniques have led to molecular definition of immunogenic tumor proteins based on their reactivity with autologous patient sera (SEREX). METHODS: Several high complexity phage-displayed cDNA libraries from breast carcinomas, human testis and breast carcinoma cell lines MCF-7, MDA-MB-468 were constructed. The cDNAs were expressed in the libraries as fusion to bacteriophage lambda protein D. Lambda-displayed libraries were efficiently screened with sera from patients with breast cancer. RESULTS: A panel of 21 clones representing 18 different antigens, including eight proteins of unknown function, was identified. Three of these antigens (T7-1, T11-3 and T11-9) were found to be overexpressed in tumors as compared to normal breast. A serological analysis of the 21 different antigens revealed a strong cancer-related profile for at least five clones (T6-2, T6-7, T7-1, T9-21 and T9-27). CONCLUSIONS: Preliminary results indicate that patient serum reactivity against five of the antigens is associated with tumor disease. The novel T7-1 antigen, which is overexpressed in breast tumors and recognized specifically by breast cancer patient sera, is potentially useful in cancer diagnosis
Cross-sectional study of hepatitis E virus (HEV) circulation in Italian pig farms
OHEJP Project: BIOPIGEE
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 dierent
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
Biosecurity measures to control hepatitis E virus on European pig farms
Hepatitis E virus (HEV) genotype 3 is a prevalent zoonotic pathogen in European pig farms, posing a significant public health risk primarily through the foodborne route. The study aimed to identify effective biosecurity measures for controlling HEV transmission on pig farms, addressing a critical gap in current knowledge. Utilizing a cross-sectional design, fecal samples from gilts, dry sows, and fatteners were collected on 231 pig farms of all farm types across nine European countries. Real-time RT-PCR was employed to test these samples for HEV. Simultaneously, a comprehensive biosecurity questionnaire captured data on various potential measures to control HEV. The dependent variable was HEV risk, categorized as lower or higher based on the percentage of positive pooled fecal samples on each farm (25% cut-off). The data were analyzed using generalized linear models (one for finisher samples and one for all samples) with a logit link function with country and farm type as a priori fixed factors. The results of the final multivariable models identified key biosecurity measures associated with lower HEV risk, which were the use of a hygienogram in the breeding (OR: 0.06, p = 0.001) and/or fattening area after cleaning (OR: 0.21, p = 0.019), the presence of a quarantine area (OR: 0.29, p = 0.025), testing and/or treating purchased feed against Salmonella (OR: 0.35, p = 0.021), the presence of other livestock species on the farm, and having five or fewer persons in charge of the pigs. Contrary to expectations, some biosecurity measures were associated with higher HEV risk, e.g., downtime of 3 days or longer after cleaning in the fattening area (OR: 3.49, p = 0.005) or mandatory handwashing for farm personnel when changing barn sections (OR: 3.4, p = 0.026). This novel study unveils critical insights into biosecurity measures effective in controlling HEV on European pig farms. The identification of both protective and risk-associated measures contributes to improving strategies for managing HEV and underscores the complexity of biosecurity in pig farming
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
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