Simona Cau
@izs-sardegna.it
Scopus Publications
- Norovirus occurrence and tissue localization in farmed Mediterranean mussels (Mytilus galloprovincialis) from Sardinia, Italy
M. Molotzu, A. Canu, T. Tedde, S. Virgilio, R. Bazzardi, R. Sau, S. Salza, G. Piras, S. Cau, B. Soro, J.G. Pereira, J.C.F. Pantoja, T. Cubeddu, S. Rocca, C. Spanu
Food Research International, 2026
Norovirus (NoV) is the leading cause of foodborne gastroenteritis worldwide, with bivalve molluscs representing a major transmission vehicle. This study investigated the occurrence, temporal variability, and tissue localization of NoV in farmed Mytilus galloprovincialis from Sardinia (Italy), integrating long-term surveillance data with experimental histological analyses. A total of 592 mussel samples collected between 2015 and 2025 within official monitoring activities were analyzed by RT-qPCR according to ISO 15216. Overall, NoV RNA was detected in 15.2% of samples. Due to uneven sampling outside the active surveillance period, statistical analyses were restricted to 2015-2018, during which both year and season significantly influenced NoV detection (p < 0.0001), with higher odds observed in 2016 and during spring, and reduced probability in summer. Due to uneven sampling outside the active surveillance period, statistical analyses were restricted to 2015-2018, during which both year and season significantly influenced NoV detection (p < 0.0001), with higher odds observed in 2016 and during spring, and reduced probability in summer. To investigate tissue-specific viral localization, mussels were experimentally exposed under controlled laboratory conditions and analyzed by immunohistochemistry. Norovirus antigens were detected intracellularly within digestive epithelial cells 24 h post-exposure, with additional focal detection in the intestine and gill epithelium, supporting a multistep uptake and retention process associated with filter feeding. Rather than challenging existing detection standards, these findings provide in situ confirmation of tissue-associated viral persistence in M. galloprovincialis and offer mechanistic support for current monitoring approaches. Overall, the integration of epidemiological and histological evidence improves understanding of norovirus persistence in Mediterranean mussel production systems and highlights implications for seasonally informed surveillance and food safety risk management. - Application of droplet digital PCR for the detection of fish DNA in food products
S. Cau, B. Soro, R. Melillo, G. Piras, S. Salza, T. Tedde, F. Pinna, B. Vodret, C. Spanu
Food Research International, 2025
Fish is one of the most common causes of food allergy. The global prevalence of fish allergy has increased over the years as a result of the increased fish consumption. In allergic individuals even small amounts of allergen can trigger a life-threatening allergic reaction. Correct food allergen labelling plays a crucial role in consumers protection. Food business operators are required to verify compliance with labelling requirements. In order to do so, they need reliable, specific and sensitive methods for the detection of fish in food products. The present study evaluated the use of a droplet digital PCR assay for the identification of fish allergen in a variety processed foods. The method was developed targeting the ribosomal 18S rRNA gene. The specificity, the limit of detection (LOD) and of quantification (LOQ), dynamic range and selectivity were evaluated. The LOD and LOQ of ddPCR were 0.08 pg/μL and 0.31 pg/μL, respectively. Following optimization and validation of the method, the digital droplet PCR was tested on 37 prepackaged food samples placed on the market. Samples comprised a variety of composite foods, including both animal and plant- origin ingredients. The presence of fish was identified in the ingredient list of some samples, while in others, it was indicated as traces or not listed at all. The presence of fish DNA was detected in 16 out of 18 labeled fish-containing samples (88.9 %), while it was never detected in foods where fish was not declared on the label. The results of this study demonstrate the strong potential of droplet digital PCR (ddPCR) as a highly sensitive and specific method for detecting fish allergens in complex food matrices. - Implementation of digestion and characterization procedures for control standardization on samples of Gilthead Seabream (Sparus aurata) and plastic polymers from the coastal environment of the Asinara Gulf (Sardinia, Italy)
Rita Melillo, Roberto Lonis, Giuseppa Lorenzoni, Gabriella Piras, Nicola Cogoni, Simona Cau, Sara Salza, Riccardo Bazzardi, Monica Molotzu, Giuseppe Esposito, Bruna Vodret, Domenico Meloni, Sebastiano Virgilio
Applied Food Research, 2025
• A digestion procedure for on animal and plastic samples was implemented. • Plastic samples were characterised by μ-FTIR. • The use of KOH 10 % was the most effective in the digestion of animal tissues. • Trial C (40 °C for 48 h) guaranteed a lower impact on plastics. • Six different polymers were identified by μ-FTIR. The objective of the present study was the implementation of a digestion procedure along with Fourier transform infrared microscopy (μ-FTIR) analysis for control standardization on samples of Gilthead Seabream ( Sparus aurata ) and different types of plastic polymers isolated in the coastal environment of the Asinara Gulf (Sardinia, Italy). The study has been carried out across two steps, the first of which was necessary to evaluate the exact amount of potassium hydroxide (KOH) at 10 % to degrade the organic matrix of gastro-intestinal tract and muscle of Gilthead Seabrams samples as much as possible without causing alterations to the eventual polymers that may be present. Moreover, the possible effects of 10 % KOH at 60 °C for 48 and 72 h and at 40 °C for 48 h were evaluated through the examination of plastic polymers that can be easily ingested by aquatic organisms under the Stereomicroscope and Scanning Electron Microscope (SEM). The second step involved the characterization of these plastic polymers by μ-FTIR.The results showed that the use of 1/10 KOH 10 % proved to be the most effective for the digestion of animal tissues, but at the same time (40 °C for 48 h) able to guarantee a lower impact on plastics and greater time savings. The characterization of plastic polymers by μ-FTIR revealed that the samples isolated from the coastal environment of the Asinara Gulf (Sardinia, Italy) were mostly represented by polyethylene, nylon, polyethylene terephthalate, polystyrene, polypropylene and polyurethane. These plastic polymers can be easily ingested by aquatic organisms and humans are exposed to them via their consumption, but so far, the consequences and potential risks have not yet been quantified. The results of the present study represent a preliminary contribution to the control standardization on samples of Gilthead Seabream ( Sparus aurata ) and different types of plastic polymers isolated in Sardinian coastal environments. - Assessment of Salmonella spp., E. coli, Vibrio parahaemolyticus and algal biotoxins in Pacific Cupped Oysters (Magallana gigas) along with monitoring of phytoplankton and hydrological parameters in water samples from an experimental facility in the Calich Lagoon (Italy)
Gabriella Piras, Anna Maria Bazzoni, Giuseppa Lorenzoni, Domenico Meloni, Rita Melillo, Riccardo Bazzardi, Simona Cau, Barbara Soro, Alida Delogu, Sara Salza, Tiziana Tedde, Nicola Fois, Giuseppe Esposito, Sebastiano Virgilio, Alessandro Graziano Mudadu
Applied Food Research, 2025
• Hydrological parameters and phytoplankton were investigated. • Biotoxins and pathogenic bacteria in oysters were determined. • The potentially toxic microalga Dinophysis acuminata was found. • No accumulation of biotoxins in oysters was pointed out. • Escherichia coli was always present overlapping the EU limits of 230 MPN/100 g. This study aimed to assess the presence ofof Salmonella spp., Escherichia coli, Vibrio parahaemolyticus and algal biotoxins in Pacific cupped oysters ( Magallana gigas while also monitoring the phytoplankton community (both toxic and non-toxic), as well as key environmental parameters including temperature, dissolved oxygen, chlorophyll a , and pH in the Calich Lagoon (Sardinia, Italy). An experimental pilot farm was set up in the frame of the EU Interreg program “RETRALAGS” and samples were collected from December 2018 to November 2019. Overall, . E. coli was always over the EU limit of 230 MPN/100 g provided for Class A areas Salmonella spp. was never detected and V. parahaemolyticus was detected only in summer samples. Only once the presence of the mixotrophic dinoflagellate Dinophysis acuminata was found, without accumulation of any biotoxins. The results confirmed the suitability of Pacific cupped oysters as bioindicators of the health status of coastal lagoon ecosystems.Microbiological parameter concentrations were strongly influenced by the season of collection and by anthropogenic activities within the lagoon's catchment area, highlighting the dynamic interaction between environmental conditions and human impact. - Comparison of digital PCR and real time PCR methods for quantitative analysis of African Swine Fever Virus
Silvia Dei Giudici, Piero Bonelli, Maria Giovanna Tilocca, Simona Cau, Pier Paolo Angioi, Anna Maria Sechi, Bruna Vodret, Annalisa Oggiano
Frontiers in Veterinary Science, 2025
Introduction The African swine fever (ASF) is a viral disease of significant socio-economic and animal health impact, commonly diagnosed using molecular techniques. The World Organization of Animal Health (WOAH) has recommended two highly sensitive and specific real time polymerase chain reaction (PCR) procedures (P1 qPCR and P2 qPCR) for the reliable and rapid detection of the ASF virus (ASFV). The present work aimed to standardize two third-generation PCR technologies by using the same WOAH-recommended primer/probe sets. Methods We developed two droplet digital PCR protocols ddPCRs and compared their analytical performances to the above-mentioned qPCRs. This involved testing serially diluted plasmid containing the vp72 gene sequence of the ASFV as the template. Clinical positive and negative samples were also analyzed to compare both PCR procedures. Results and discussion The ddPCR assays demonstrated excellent linearity ( R 2 = 0.999) across a dynamic range from 10 4 to 1 copies/μl. The limits of detections (LOD) were 3.48 and 2.80 copies/μl and the limit of quantifications (LOQs) were ranging from 25 and 20 copies/μl for the P1 and the P2 procedures, respectively. The LOD values were comparable to those of qPCRs assays. The analysis of the clinical samples evidenced a strong agreement between the qPCR and the ddPCR, with bias values below 0.20, as determined by Bland-Altman analysis. The results of this study indicated that the ddPCR method can be adapted to existing validated qPCR protocols, enabling the quantification of low viral titer samples with similar analytical sensitivity. Moreover, the use of ddPCR allows for the absolute quantification without the need of a calibration curve, providing a reliable tool for ASFV diagnosis and outbreak management. It could also support global effort to control the spread of ASFV. Further validation in diverse matrices (e.g., feed and environmental swabs) could expand its applicability in the One Health frameworks. - DETERMINATION OF MICROBIOLOGICAL PARAMETERS, ALGAL BIOTOXINS AND TRACE ELEMENTS IN OYSTERS FROM A MEDITERRANEAN LAGOON
Veterinarija Ir Zootechnika, 2024 - Trend of Pathogenic Vibrio parahaemolyticus Occurrences in Bivalve Molluscs Harvested in Sardinian Coastal Environments Between 2011 and 2018
Giuseppe Tedde, Giuseppa Lorenzoni, Domenico Meloni, Sara Salza, Rita Melillo, Riccardo Bazzardi, Simona Cau, Tiziana Tedde, Gabriella Piras, Maria Teresa Uda, Francesca Leoni, Giuseppe Esposito, Sebastiano Virgilio, Alessandro Graziano Mudadu
Journal of Food Protection, 2023
The aim of the present study was to evaluate Vibrio parahaemolyticus occurrences in bivalve molluscs harvested from Sardinian coastal environments between 2013 and 2015. The prevalence of pathogenic V. parahaemolyticus isolates is based on the detection of the two major virulence genes thermostable direct hemolysin (tdh) and thermolabile hemolysin (trh) To assess changes between 2011 and 2018 in the prevalence of V. parahaemolyticus in bivalve molluscs, we compared our results with those of previous investigations. In total, 2,933 samples were collected: 1,079 in 2013, 1,288 in 2014, and 566 in 2015. The mean prevalence of V. parahaemolyticus in shellfish was 3.5% in 2013, 1.7% in 2014, and 3.5% in 2015. The highest percentage of positive samples in 2013 and 2014 was observed in clams (3.5% and 2.7%, respectively), whereas in 2015, it was reported in oysters (15.1%). By comparing the sampling period of 2011-2014 with that of 2015-2018, an increase in the prevalence of V. parahaemolyticus was observed in shellfish (p < 0.05). In parallel, 208 potentially enteropathogenic V. parahaemolyticus strains were identified through the years 2011-2018 and, in particular, 10 trh+ and six tdh+ isolates. Our present study provides information regarding trends of V. parahaemolyticus occurrences in bivalve molluscs harvested from Sardinian coastal environments between 2011 and 2018 suggesting that the prevalence varies depending on the sampling period and shellfish species. - Experimental infection of Aedes (Stegomyia) albopictus and Culex pipiens mosquitoes with Bluetongue virus
Salvatore Ledda, Cipriano Foxi, Giantonella Puggioni, Roberto Bechere, Angela Maria Rocchigiani, Rosario Scivoli, Elisabetta Coradduzza, Simona Cau, Luigi Vento, Giuseppe Satta
Medical and Veterinary Entomology, 2023
Bluetongue disease (BT), caused by Bluetongue virus (BTV), infects wild and domestic ruminants, causing severe economic damage in the cattle and sheep industry. Proven vectors of BTV are biting midges belonging to the Culicoides genus, but other arthropods are considered potential vectors, such as ticks, mosquitoes, wingless flies, and sand flies. The present study represents the first attempt to evaluate the vectorial capacity of Culex pipiens and Aedes albopictus for BTV. Mosquitoes were artificially fed with blood containing BTV serotype 1. Infection, dissemination and transmission rates were evaluated at 0, 3, 7, 14 and 21 days after an infected blood meal. Viral RNA was only detected up to 3 days post infection in the bodies of both species. This study indicates that the two Italian populations of Cx. pipiens and Ae. albopictus are not susceptible to BTV infection. - A Year of Bio-Monitoring (2021): Presence of Algae of the Genus Alexandrium, Dinophysis, Prorocentrum and Non-Compliance for Paralytic Toxins and Lipophilic Toxins in Bivalve Mollusks Bred in Sardinia (W Mediterranean Sea)
Giuseppa Lorenzoni, Anna Maria Bazzoni, Monica Cangini, Sonia Dall’Ara, Rita Melillo, Alessandro Graziano Mudadu, Simona Cau, Barbara Soro, Salvatore Ledda, Gabriella Piras, Tiziana Tedde, Sara Salza, Igor Arras, Giuseppa Porqueddu, Domenico Meloni
Journal of Marine Science and Engineering, 2023
Bivalve mollusk production represents the principal aquaculture activity in Sardinia (40°03′ N, 9°05′ E). In 2021, 859 water samples and 1270 mollusk samples were analyzed. The species Alexandrium minutum caused the accumulation of Paralytic Shellfish Toxins (PST) in three samples of bivalve mollusks. Dinophysis acuminata complex caused the accumulation of lipophilic toxins (LTs) belonging to the okadaic acid group (OAs) in 18 samples of bivalve mollusks. The research of paralytic shellfish toxins (PSTs) in shellfish samples has been carried out with LC-FLD, as mentioned in the AOAC 2005 Official Method 2005.06. The determination of LTs was carried out by LC-MS/MS analysis. DTX2, belonging to the group of OA toxins, was detected for the first time in Sardinia, in mussels sampled in Tortolì. The presence of Dinophysis and Prorocentrum species was correlated with the accumulation of the OA toxin group in bivalve mollusks, showing a certain repeatability at certain times of the year in the areas included in the study. The results of the present study can help to plan and organize more effective bio-monitoring sampling strategies. - Survival of Naturally Contaminating Listeria monocytogenes in Commercial Mediterranean-Style Dry Fermented Sausages during Storage
ALESSANDRO G. MUDADU, GABRIELLA PIRAS, RITA MELILLO, SARA SALZA, SIMONA CAU, SEBASTIANO VIRGILIO, DOMENICO MELONI, PIERA MELE
Journal of Food Protection, 2022
The aim of the present study was the determination of Listeria monocytogenes, competitive microbiota, microbial hygiene indicators, and physicochemical parameters in the typical Mediterranean-style fermented sausages Salsiccia Sarda. A batch of Salsiccia Sarda (25 samples) naturally contaminated by L. monocytogenes and vacuum packaged after 24 days of ripening was included in the study. Fifteen samples stored at 8°C were analyzed after 13 days, after 90 days, and at the end of shelf life (after 180 days from vacuum packaging). Ten vacuum-packaged samples were stored at 12°C in a domestic fridge simulating temperature abuse and were evaluated at the end of the shelf life. Samples were subjected to physicochemical analysis (pH and water activity) and investigated for the presence and enumeration of L. monocytogenes. Competitive microbiota, lactic acid bacteria, coagulase-negative staphylococci, and microbial hygiene indicators (total mesophilic bacterial counts, Enterobacteriaceae, Enterococcuss spp., and Staphylococcus aureus) were determined in all the samples. Although a decreasing trend in L. monocytogenes prevalence was observed through the shelf life, the detection of this pathogen in fermented sausages confirms its ability to overcome hurdles of the manufacturing process. The results highlight the importance of the careful evaluation of the Salsiccia Sarda production process by food business operators to maintain unfavorable conditions for the growth of L. monocytogenes. HIGHLIGHTS - Detection of Fish Allergens in Foods Using an In-House Real-Time PCR Targeting the Ribosomal 18S rRNA Gene
Simona Cau, Cinzia Daga, Carlo Spanu, Barbara Soro, Tiziana Tedde, Sara Salza, Rita Melillo, Gabriella Piras, Sebastiano Virgilio, Bruna Vodret, Alessandro Graziano Mudadu
Foods, 2022 - Determination of phytoplank-ton in water samples, algal biotoxins, microbiological parameters and microplastics in Mediterranean mussels (Mytilus galloprovincialis Lamarck, 1819) from an experimental pilot farm in the Calich Lagoon (Sardinia, Italy)
Alessandro Graziano Mudadu, Anna Maria Bazzoni, Rita Melillo, Giuseppa Lorenzoni, Gabriella Piras, Sara Salza, Simona Cau, Barbara Soro, Bruna Vodret, Tiziana Tedde, Nicola Fois, Simonetto Serra, Sebastiano Virgilio, Domenico Meloni
Italian Journal of Food Safety, 2022 - Identification and quantification of potential microplastics in shellfish harvested in Sardinia (Italy) by using transillumination stereomicroscopy
Giuseppa Lorenzoni, Rita Melillo, Alessandro Graziano Mudadu, Gabriella Piras, Simona Cau, Katia Usai, Luisa Corda, Sara Salza, Tiziana Tedde, Bruna Vodret, Sebastiano Virgilio, Domenico Meloni
Italian Journal of Food Safety, 2022 - Detection of celery (Apium graveolens) allergen in foods of animal and plant origin by droplet digital PCR assay
S. Cau, M.G. Tilocca, C. Spanu, B. Soro, T. Tedde, S. Salza, R. Melillo, G. Piras, S. Virgilio, B. Vodret, A.G. Mudadu
Food Control, 2021 - Longitudinal study on seasonal variation of marine biotoxins and related harmful algae in Bivalve Mollusks bred in Sardinia (Italy, W mediterranean sea) from 2015 to 2020 and assessment of potential public health risks
Alessandro G. Mudadu, Anna Maria Bazzoni, Virgilio Congiu, Giuseppe Esposito, Alberto Cesarani, Rita Melillo, Giuseppa Lorenzoni, Simona Cau, Barbara Soro, Bruna Vodret, Domenico Meloni, Sebastiano Virgilio
Journal of Marine Science and Engineering, 2021 - New evidence of pectenotoxins in farmed bivalve molluscs from sardinia (Italy)
Alessandro G. Mudadu, Anna Maria Bazzoni, Rita Melillo, Cecilia Teodora Satta, Simona Cau, Virgilio Congiu, Barbara Soro, Riccardo Bazzardi, Giuseppa Lorenzoni, Gabriella Piras, Nadia Bardino, Bruna Vodret, Sebastiano Virgilio
Italian Journal of Food Safety, 2021 - Detection of fish allergen by droplet digital PCR
Cinzia Daga, Simona Cau, Maria Giovanna Tilocca, Barbara Soro, Aldo Marongiu, Bruna Vodret
Italian Journal of Food Safety, 2018
