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1.
Mar Drugs ; 22(3)2024 Mar 05.
Article in English | MEDLINE | ID: mdl-38535463

ABSTRACT

This study reports the first detection of the marine neurotoxin pinnatoxin-G (PnTX-G) in clams collected in the northwestern Adriatic Sea (Italy). It also represents the first report of the potential toxin-producing dinoflagellate, Vulcanodinium rugosum, in Italian seas. This result, from the coasts of the Emilia-Romagna Region, indicates a successful colonization process, reflecting conditions in France where V. rugosum was initially documented. In this case, the concentration of PnTXs was very low, making further sampling necessary to fully understand the extent of the phenomenon. Discussions on the need to obtain more data to support a proper risk assessment and the need to implement a monitoring program that includes emerging marine biotoxins are also included.


Subject(s)
Alkaloids , Dinoflagellida , Spiro Compounds , Humans , France , Italy
2.
Foodborne Pathog Dis ; 21(1): 27-35, 2024 01.
Article in English | MEDLINE | ID: mdl-37878812

ABSTRACT

Norovirus (NoV) is an enteric virus with foodborne transmission. Bivalve shellfish are a main source of infections and outbreaks. In Italy a voluntary based monitoring plan to check the safety of bivalve shellfish was set up at provincial level. This study describes the occurrence and distribution of NoV in the Northern Adriatic Sea and in the Ligurian Sea. From October 2018 to September 2020, 807 bivalve shellfish samples (n = 205 oysters, n = 182 mussels, n = 348 clams, n = 72 other bivalve shellfish) were tested by One-Step Retrotranscription Real-time polymerase chain reaction for NoV GI and GII and quantified according to the ISO 15216-2:2013 and ISO 15216-1:2017. Positive samples were further analyzed to determine genotype by sequencing of the ORF1/ORF2 junction of the viral genome. A total of 126 samples were positive for NoV, mussels, and oysters had the highest probability of being positive and positive samples were found mainly in the colder season. Of these samples, 46% were NoV GII, 13% NoV GI, and 40% carried both genogroups. Thirty-seven samples were typeable (GI n = 12 and GII n = 25) with GI samples belonging to four genotypes and GII samples belonging to five genotypes. GII.3 genotype was the most prevalent, followed by GII.4, particularly Sydney 2012 subtype, a leading cause of infections worldwide, was found in three oysters' and three clams' samples. The phylogenetic analysis revealed a high heterogeneity among the species that are scattered in several clusters. Considering the low infectious dose the overall presence of NoV in edible shellfish, particular those to be eaten raw or undercooked, is moderately high. The presence of genotypes frequently involved in human infections strengthens the need for ongoing monitoring, which should be extended at national level.


Subject(s)
Bivalvia , Caliciviridae Infections , Norovirus , Ostreidae , Animals , Humans , Genotype , Norovirus/genetics , Phylogeny , Shellfish , Italy/epidemiology , Oceans and Seas
3.
Foods ; 11(14)2022 Jul 14.
Article in English | MEDLINE | ID: mdl-35885339

ABSTRACT

In 2019, SARS-CoV-2 was identified as the cause of an easily transmissible disease that was declared as a world pandemic. Foodborne transmission was never reported. However, early studies suggested that food could be involved in SARS-CoV-2 entry in the human gastrointestinal tract leading to possible infection, and highlighting the importance of further studies to inspect possible issues linked to food consumption. In this perspective, this work aimed at monitoring SARS-CoV-2 presence in some food and mains water samples in Northern Italy during the COVID-19 pandemic (2020-2022). A total of 1806 foods, 112 mains water samples, and 580 swabs on meat and dairy product surfaces were analyzed for SARS-CoV-2 RNA detection by Real-time PCR. All the analyzed samples were negative to viral RNA detection with the exception of one vegetable sample. Even if data on foodborne coronavirus transmission suggested a limited importance of this pathway, the impact of the current pandemic in Northern Italy deserved a rigorous investigation to rule out such possibility. Indeed, gaining insight on all SARS-CoV-2 possible transmission pathways, including the foodborne route, seemed of interest to maintain consumers' confidence and trust in food safety, and for the effective management of the current, and future, possible pandemics.

4.
Microorganisms ; 10(2)2022 Jan 22.
Article in English | MEDLINE | ID: mdl-35208696

ABSTRACT

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.

5.
Food Environ Virol ; 14(1): 69-76, 2022 03.
Article in English | MEDLINE | ID: mdl-34698989

ABSTRACT

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.


Subject(s)
Hepatitis A virus , Norovirus , Animals , Food Contamination/analysis , Food Microbiology , Hepatitis A virus/genetics , Italy , Norovirus/genetics , Vegetables
6.
Foods ; 10(5)2021 May 19.
Article in English | MEDLINE | ID: mdl-34069582

ABSTRACT

Salmonella and Campylobacter ssp. are bacterial pathogens responsible for most foodborne infections in EU countries. Poultry serves as a reservoir for these pathogens, and its important role in the meat industry makes it essential to develop a rapid detection assay able to provide results in one day. Indeed, the rapid identification of foodborne pathogens is an important instrument for the monitoring and prevention of epidemic outbreaks. To date, Salmonella and Campylobacter screening is mainly conducted through molecular methods (PCR or real-time PCR) performed after 18-24 h long enrichments. In this study, we evaluated short enrichments (0, 2, 4, and 6 h) combined with a colorimetric loop-mediated isothermal AMPlification (LAMP) or real-time PCR to detect Salmonella and Campylobacter in poultry meat contaminated at different concentration levels (101, 103, and 105 CFU/g). Our results show that real-time PCR allows the detection of Salmonella and Campylobacter, even after shorter enrichment times than prescribed by ISO references; particularly, it detected Salmonella down to 101 CFU/g since T0 and Campylobacter from 103 CFU/g since T0. Detection with LAMP was comparable to real-time PCR without the requirement of a thermal cycler and with shorter execution times. These characteristics make colorimetric LAMP a valid alternative when one-day results are needed, improving the timely identification of positive meat batches, even in the absence of specialized instrumentation.

7.
Viruses ; 13(2)2021 02 03.
Article in English | MEDLINE | ID: mdl-33546342

ABSTRACT

Mammalian orthoreoviruses (MRVs) are emerging infectious agents that may affect wild animals. MRVs are usually associated with asymptomatic or mild respiratory and enteric infections. However, severe clinical manifestations have been occasionally reported in human and animal hosts. An insight into their circulation is essential to minimize the risk of diffusion to farmed animals and possibly to humans. The aim of this study was to investigate the presence of likely zoonotic MRVs in wild ungulates. Liver samples were collected from wild boar, red deer, roe deer, and chamois. Samples originated from two areas (Sondrio and Parma provinces) in Northern Italy with different environmental characteristics. MRV detection was carried out by PCR; confirmation by sequencing and typing for MRV type 3, which has been frequently associated with disease in pigs, were carried out for positive samples. MRV prevalence was as high as 45.3% in wild boars and 40.6% in red deer in the Sondrio area, with lower prevalence in the Parma area (15.4% in wild boars). Our findings shed light on MRV occurrence and distribution in some wild species and posed the issue of their possible role as reservoir.


Subject(s)
Animals, Wild/virology , Artiodactyla/virology , Orthoreovirus, Mammalian/isolation & purification , Animals , Animals, Wild/classification , Artiodactyla/classification , Disease Reservoirs/veterinary , Disease Reservoirs/virology , Italy/epidemiology , Liver/virology , Orthoreovirus, Mammalian/genetics , Prevalence , RNA, Viral/genetics , Serogroup
8.
Pediatr Infect Dis J ; 40(1): 1-5, 2021 01.
Article in English | MEDLINE | ID: mdl-32898091

ABSTRACT

BACKGROUND: The aim of the present work was to investigate family clusters of Shiga toxin-producing Escherichia coli (STEC) infection among the household members of STEC positive patients, identified within a screening program of bloody diarrhea (BD) for STEC in Northern Italy. METHODS: Stool samples from patients with BD or BD-associated-hemolytic uremic syndrome (HUS) and related households were investigated by molecular and bacteriologic methods to detect and characterize the virulence profile of STEC and Pulsed Field Gel Electrophoresis analysis were done on isolates. RESULTS: Thirty-nine cases of STEC infection (isolated BD in 16, BD-associated-HUS in 23) were considered, and a total of 130 stool samples from 1 to 8 households of the index patient were analyzed. The prevalence of positivity was higher in siblings (34.8%, 8/23) than in mothers (20%, 7/35), grandparents (9.5%, 2/21), fathers (8.8%, 3/34) or other households. In 14 clusters (36%), one or more household shared a STEC with the same virulence profile (stx, eae, serogroup) as the index case. In 7 clusters, STEC strains isolated from at least 2 subjects also shared identical Pulsed Field Gel Electrophoresis profile. The frequency of household infection does not appear to be associated to the index case's illness (HUS or BD), nor with the serotype or with the virulence profile of the involved STEC (stx2 or stx1-stx2). CONCLUSIONS: Our study shows that STEC infections, most likely related to human-to-human transmission, are common among households of patients with STEC BD or HUS and underlines the importance of extending the epidemiologic investigations to all family members, as the index case may not always be the primary infection in the family.


Subject(s)
Disease Outbreaks , Escherichia coli Infections , Shiga-Toxigenic Escherichia coli , Cross-Sectional Studies , Diarrhea , Escherichia coli Infections/epidemiology , Escherichia coli Infections/transmission , Family Characteristics , Feces/microbiology , Female , Hemolytic-Uremic Syndrome , Humans , Male
9.
Front Mol Biosci ; 7: 155, 2020.
Article in English | MEDLINE | ID: mdl-32850953

ABSTRACT

Quantitative PCR (qPCR) is a widely used method for nucleic acid quantification of various pathogenic microorganisms. For absolute quantification of microbial load by qPCR, it is essential to create a calibration curve from accurately quantified quantification standards, from which the number of pathogens in a sample is derived. Spectrophotometric measurement of absorbance is a routine method for estimating nucleic acid concentration, however, it may be affected by presence of other potentially contaminating nucleic acids or proteins and salts. Therefore, absorbance measurement is not reliable for estimating the concentration of stock solutions of quantification standards, based on which they are subsequently diluted. In this study, we utilized digital PCR (dPCR) for absolute quantification of qPCR plasmid standards and thus detecting possible discrepancies in the determination of the plasmid DNA number of standards derived from UV spectrophotometry. The concept of dPCR utilization for quantification of standards was applied on 45 qPCR assays using droplet-based and chip-based dPCR platforms. Using dPCR, we found that spectrophotometry overestimated the concentrations of standard stock solutions in the majority of cases. Furthermore, batch-to-batch variation in standard quantity was revealed, as well as quantitative changes in standards over time. Finally, it was demonstrated that droplet-based dPCR is a suitable tool for achieving defined quantity of quantification plasmid standards and ensuring the quantity over time, which is crucial for acquiring homogenous, reproducible and comparable quantitative data by qPCR.

10.
Front Microbiol ; 8: 1174, 2017.
Article in English | MEDLINE | ID: mdl-28702010

ABSTRACT

The demand for rapid methods for the quantification of pathogens is increasing. Among these methods, those based on nucleic acids amplification (quantitative PCRs) are the most widespread worldwide. Together with the qPCR, a new approach named digital PCR (dPCR), has rapidly gained importance. The aim of our study was to compare the results obtained using two different dPCR systems and one qPCR in the quantification of three different bacterial pathogens: Listeria monocytogenes, Francisella tularensis, and Mycobacterium avium subsp. paratuberculosis. For this purpose, three pre-existing qPCRs were used, while the same primers and probes, as well as PCR conditions, were transferred to two different dPCR systems: the QX200 (Bio-Rad) and the Quant Studio 3D (Applied Biosystems). The limits of detection and limits of quantification for all pathogens, and all PCR approaches applied, were determined using genomic pure DNAs. The quantification of unknown decimal suspensions of the three bacteria obtained by the three different PCR approaches was compared through the Linear Regression and Bland and Altman analyses. Our results suggest that, both dPCRs are able to quantify the same amount of bacteria, while the comparison among dPCRs and qPCRs, showed both over and under-estimation of the bacteria present in the unknown suspensions. Our results showed qPCR over-estimated the amount of M. avium subsp. paratuberculosis and F. tularensis cells. On the contrary, qPCR, compared to QX200 dPCR, under-estimated the amount of L. monocytogenes cells. However, the maximum difference among PCRs approaches was <0.5 Log10, while cultural methods underestimated the number of bacteria by one to two Log10 for Francisella tularensis and Mycobacterium avium subsp. paratuberculosis. On the other hand, cultural and PCRs methods quantified the same amount of bacteria for L. monocytogenes, suggesting for this last pathogen, PCRs approaches can be considered as a valid alternative to the cultural ones.

11.
Ital J Food Saf ; 5(3): 5848, 2016 Jun 03.
Article in English | MEDLINE | ID: mdl-27853714

ABSTRACT

In temperate climates, a seasonal trend was observed in the incidence of human campylobacteriosis cases, with peaks reported in spring and autumn in some countries, or in summer in others; a similar trend was observed in Campylobacter spp. dairy cattle faecal shedding, suggesting that cattle may play a role in the seasonal peak of human infection. The objectives of this study were to assess if a seasonal trend in thermophilic Campylobacter spp. contamination of raw milk exists and to evaluate a possible relation between this and the increase of human campylobacteriosis incidence in summer months. The results showed a mean prevalence of 1.6% of milk samples positive for thermophilic Campylobacter spp. with a wide range (0.0-3.1%) in different months during the three years considered. The statistical analysis showed a significant difference (P<0.01) of the prevalence of positive samples for thermophilic Campylobacter spp. between warmer and cooler months (2.3 vs 0.6%). The evidence of a seasonal trend in thermophilic Campylobacter spp. contamination of raw milk sold for direct consumption, with an increase of the prevalence in warmer months, may represent one of the possible links between seasonal trend in cattle faecal shedding and seasonal trend in human campylobacteriosis.

12.
Ital J Food Saf ; 4(3): 4585, 2015 Jun 30.
Article in English | MEDLINE | ID: mdl-27800408

ABSTRACT

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.

13.
Ital J Food Saf ; 4(2): 4587, 2015 May 28.
Article in English | MEDLINE | ID: mdl-27800394

ABSTRACT

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.

14.
J Food Prot ; 78(1): 13-21, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25581173

ABSTRACT

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.


Subject(s)
Food Microbiology/statistics & numerical data , Listeria monocytogenes/isolation & purification , Milk/microbiology , Raw Foods/microbiology , Salmonella/isolation & purification , Algorithms , Animals , Food Dispensers, Automatic/standards , Food Handling , Hot Temperature , Humans , Italy/epidemiology , Listeriosis/epidemiology , Models, Statistical , Normal Distribution , Risk Assessment , Salmonella Food Poisoning/epidemiology
15.
Food Environ Virol ; 7(1): 76-85, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25344058

ABSTRACT

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.


Subject(s)
Bivalvia/virology , Food Preservation/methods , Hepatitis A virus/chemistry , Shellfish/virology , Animals , Food Contamination/analysis , Food Preservation/instrumentation , Hepatitis A virus/growth & development , Hot Temperature , Hydrostatic Pressure
16.
Food Environ Virol ; 6(3): 202-6, 2014 Sep.
Article in English | MEDLINE | ID: mdl-24859055

ABSTRACT

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%.


Subject(s)
Food Contamination/analysis , Frozen Foods/virology , Fruit/virology , Hepatitis A virus/genetics , Hepatitis A virus/isolation & purification , Genome, Viral , Hepatitis A virus/classification , Italy , Molecular Sequence Data , Phylogeny
17.
Ital J Food Saf ; 3(1): 2112, 2014 Jan 21.
Article in English | MEDLINE | ID: mdl-27800321

ABSTRACT

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.

18.
Ital J Food Saf ; 3(1): 2231, 2014 Jan 21.
Article in English | MEDLINE | ID: mdl-27800323

ABSTRACT

According to EC Regulation No 2073/2005, for food business operators that produce ready-to-eat (RTE) product, it is crucial to be able to demonstrate if the product supports the growth of Listeria monocytogenes. The objective of the study was therefore to evaluate the behaviour of L. monocytogenes in sliced RTE turkey bresaola (made by cured turkey breast 4.5% NaCl, 1% sodium lactate, sodium nitrite 150 ppm and flavouring) during the shelf life of the product, simulating a contamination during the slicing operation. Considering a shelf life of 90 days, as defined by manufacturer, the packages of sliced bresaola were stored at 5°C for 7 days and at 8°C for the remaining storage time (83 days). L. monocytogenes count decreased during storage test from 1.43/1.98 log cfu/g in the three batches tested to 1.03 log cfu/g in one batch and to undetectable levels in the other two batches. The results show that the investigated product is unable to support the growth of L. monocytogenes.

19.
Ital J Food Saf ; 3(1): 2243, 2014 Jan 21.
Article in English | MEDLINE | ID: mdl-27800324

ABSTRACT

Formagelle di capra is a raw goat cheese produced from whole chilled goat milk; traditional technology involving unpasteurised milk and indigenous lactic starter cultures is employed for its production in Italy. The purpose of this study was to assess the behaviour of Escherichia coli O157:H7 during the manufacturing and ripening of this raw goat milk cheese. Raw milk was experimentally inoculated with E. coli O157:H7 in a laboratory scale plant and the count was monitored during production and 30 days of ripening required for this cheese. Results showed that E. coli O157:H7 count increased to more than 1.5 Log cfu g-1 during cheese production and remained constant until the end of ripening. The evidence that E. coli O157:H7 is able to survive during the manufacturing and ripening process suggests that the 30-day ripening period alone is insufficient to eliminate levels of viable E. coli O157:H7 in Formaggelle di capra cheese and that the presence of low numbers of E. coli O157:H7 in milk destined for the production of raw goat milk cheeses could represent a potential source of infection for humans and a threat for consumers.

20.
Int J Food Microbiol ; 184: 134-8, 2014 Aug 01.
Article in English | MEDLINE | ID: mdl-24513055

ABSTRACT

The classical microbiological method for detection of Salmonella spp. requires more than five days for final confirmation, and consequently there is a need for an alternative methodology for detection of this pathogen particularly in those food categories with a short shelf-life. This study presents an international (at European level) ISO 16140-based validation study of a non-proprietary Real-Time PCR-based method that can generate final results the day following sample analysis. It is based on an ISO compatible enrichment coupled to an easy and inexpensive DNA extraction and a consolidated Real-Time PCR assay. Thirteen laboratories from seven European Countries participated to this trial, and pork meat was selected as food model. The limit of detection observed was down to 10 CFU per 25 g of sample, showing excellent concordance and accordance values between samples and laboratories (100%). In addition, excellent values were obtained for relative accuracy, specificity and sensitivity (100%) when the results obtained for the Real-Time PCR-based methods were compared to those of the ISO 6579:2002 standard method. The results of this international trial demonstrate that the evaluated Real-Time PCR-based method represents an excellent alternative to the ISO standard. In fact, it shows an equal and solid performance as well as it reduces dramatically the extent of the analytical process, and can be easily implemented routinely by the Competent Authorities and Food Industry laboratories.


Subject(s)
Food Microbiology/methods , Meat/microbiology , Real-Time Polymerase Chain Reaction/standards , Salmonella/isolation & purification , Animals , DNA, Bacterial/analysis , Europe , Salmonella/genetics , Sensitivity and Specificity , Swine
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