Trend of Pathogenic Vibrio parahaemolyticus Occurrences in Bivalve Molluscs Harvested in Sardinian Coastal Environments Between 2011 and 2018.

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.

Detection of Fish Allergens in Foods Using an In-House Real-Time PCR Targeting the Ribosomal 18S rRNA Gene.

Fish is one of the major food allergens which, in sensitised individuals, can cause life-threatening allergic reactions, even when present in small amounts. To protect consumers' health, the correct labeling of foods is important. The objective of the present study was to validate an in-house real-time PCR method targeting the ribosomal 18S rRNA gene as universal DNA marker for the detection of fish in foods. The specificity of the primers was assessed on 20 fish species commonly marketed in the Mediterranean basin and other species of molluscs and crustaceans and foods of animal and plant origin. The absolute detection of the method was assessed using DNA extracted from a fish mixture and the SureFood® QUANTARD Allergen 40 reference material. The relative amount was assessed on a fish and béchamel sauce blend. Commercial food samples either labelled with or without fish in the ingredient list, were tested for the presence of fish DNA. The primer showed high specificity against the selected fish species. The limit of detection (LOD) and limit of quantification (LOQ) of the in-house method were 0.5 pg/µL and 5 pg/µL, respectively. The relative quantification in fish and béchamel blend samples detected a concentration as low as 0.000025%, corresponding to 0.25 mg/kg of fish, indicating the suitability of the method in a food matrix. The presence of fish DNA was always detected in commercial samples in which the presence of fish was listed in the ingredient list. The method was able to detect the presence of fish DNA also in samples in which the presence of fish was indicated as traces or was not declared on the label. The proposed method was demonstrated to be a reliable, specific, and sensitive method for the detection of fish allergens in foods. Therefore, the proposed real-time PCR method could be used as a useful instrument in the verification of compliance with allergen labelling regulations.

Survival of Naturally Contaminating Listeria monocytogenes in Commercial Mediterranean-Style Dry Fermented Sausages during Storage.

ABSTRACT: 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.

Determination of phytoplankton 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).

The aims of this paper were to collect and analyse preliminary data of phytoplankton in the water, biotoxins, Escherichia coli, Salmonella spp., Vibrio spp. and microplastic eventually present in farmed mussels, and to acquire information about the production capability from an experimental pilot farm of the Calich Lagoon. Two sampling sessions were carried out, in February and in May 2019, also monitoring the water condition (pH, temperature, salinity, dissolved oxygen, chlorophyll a). No potentially toxic algae were detected, and moreover no biotoxins (Paralytic Shellfish Poison, Diarrheic Shellfish Poison, Amnesic Shellfish Poison) were found in mussels. E.coli was present with the highest concentration in February (16000 MPN/100g e.p.). Salmonella and Vibrio spp. have not been detected. Almost a microplastic per grams was found, mainly fiber of different colours. Further studies, carried out for several months, will allow to better understand the possible problems related to the production of mussels in a lagoon not yet classified as a shellfish production area.

Identification and quantification of potential microplastics in shellfish harvested in Sardinia (Italy) by using transillumination stereomicroscopy.

Plastics are non-biodegradable polymers made up of different groups of petrochemical materials. Several biotic and abiotic factors can change the density of plastic fragmenting it and originating microplastics (MPs). MPs have been defined as small pieces of plastic less than 5 mm in size. Due to their small size, they are an emerging concern in the marine environment since they can be ingested by aquatic organisms, especially filter-feeding organisms, such as bivalve mollusks. Impacts of MPs exposure have been shown at various levels of biological organization, from cellular to tissue to individual and population levels. For example, oxidative stress and inflammation have been observed in copepods and mussels, obstruction and physical damage of the digestive tract were found in fish and swimming behavior alterations, disruption of foraging and feeding behavior and overall reduced fitness and survival were observed in fish and oysters. In addition, MPs can act as a vector for the transfer of chemicals to marine biota. The aim of the present study was the identification and quantification of potential MPs in shellfish harvested in Sardinia (Italy) by using transillumination stereomicroscopy. Bivalves were collected from 4 of the main production areas located along the Sardinian coast and selected according to the principles of the risk assessment. The results of the present study demonstrated the presence of potential MPs in 70% of the analyzed samples: the presence of MPs in bivalve mollusks may pose a threat to food safety, and there is an urgent need to evaluate the potential risks of MPs to human health.

New evidence of pectenotoxins in farmed bivalve molluscs from Sardinia (Italy).

Several planktonic dinoflagellates can produce lipophilic phycotoxins that represent a significant threat to public health as well as to shellfish and fish farming. Poisoning related to some of these toxins is categorised as diarrhetic shellfish poisoning. We analysed 975 shellfish samples from Tortoli in the central-eastern region of Sardinia (Italy) from January 2016 to March 2020, to investigate the prevalence of different lipophilic marine biotoxins in mollusc bivalves. The results highlighted the predominant presence of toxins belonging to the okadaic acid group in all samples with toxin concentrations exceeding legal limits, and revealed the new occurrence of pectenotoxins in oysters and clams with a winter seasonality in recent years. The origin of shellfish toxicity was associated with the same Dinophysis species, mainly D. acuminata. Based on both these results and other precedents, monitoring and recording systems are strongly recommended.

Presence, Seasonal Distribution, and Biomolecular Characterization of Vibrio parahaemolyticus and Vibrio vulnificus in Shellfish Harvested and Marketed in Sardinia (Italy) between 2017 and 2018.

ABSTRACT: In the present study, we investigated the presence, seasonal distribution, and biomolecular characteristics of Vibrio parahaemolyticus and Vibrio vulnificus in samples of bivalve mollusks (Mytilus galloprovincialis, Crassostrea gigas, and Ruditapes decussatus) harvested and marketed in Sardinia (Italy) between 2017 and 2018. A total of 435 samples were submitted for qualitative determination of Vibrio spp., V. parahaemolyticus, and V. vulnificus. Potentially enteropathogenic isolates were detected with biomolecular methods. The overall prevalence of Vibrio spp. was 7.6%. The highest Vibrio prevalence was found in R. decussatus (8.3%). The prevalences of V. parahaemolyticus and V. vulnificus were 2.7 and 4.8%, respectively. Higher prevalences of V. parahaemolyticus and V. vulnificus were found in R. decussatus (4.2%) and C. gigas (6.2%), respectively. Only two pathogenic V. parahaemolyticus strains were recovered (genotypes: tdh- and trh+; tdh+ and trh-), both from M. galloprovincialis. None of the isolates were tdh+ and trh+. Pathogenic Vibrio infections are often underestimated, and human infections are increasing in Europe. European data on the true distribution of Vibrionaceae are scarce, and the results of the present study highlight the need of constant monitoring to update the distribution of pathogenic vibrios.

Influence of seasonality on the presence of okadaic acid associated with Dinophysis species: A four-year study in Sardinia (Italy).

In Sardinia (Italy), bivalve molluscs production plays an important role in the trade balance. Diarrhoetic shellfish poisoning (DSP), an intoxication caused by the ingestion of bivalve molluscs that have accumulated high levels of Okadaic acid (OA), may represent a serious risk for the public health and a remarkable economic loss for the producers. Aim of this work was to improve knowledge about the repeatability of OA accumulation phenomena in various seasons trying to understand whether or not there was a trend. Also, the interaction between toxic algae and OA accumulation was examined. In this study, data of lipophilic toxins, water temperature and abundance of DSP-producing microalgal species were collected in a four-year period (2015-2018) in coastal production areas of Sardinia. Several episodes of OA positive values (>160 eq µgAO/Kg pe, Reg 853/04) were recorded during the study period in different production areas of Sardinia and in different seasons. A seasonal repeatability of OA accumulation in molluscs was observed in some production areas; moreover, different temporal gaps between the presence of toxic algae and OA accumulation were reported. Toxicity was observed almost exclusively in Mytilus galloprovincialis Lamark (99%), being this matrix the most abundant species bred in Sardinia.

Recent findings of paralytic shellfish toxins linked to the genus Alexandrium Halim in Mediterranean mollusc production areas.

Paralytic shellfish poisoning is a human intoxication syndrome associated with the consumption of seafood that has been contaminated with paralytic shellfish toxins (PSTs), a group of natural neurotoxic alkaloids produced by marine dinoflagellates, including some Alexandrium species. This study presents findings of PSTs in mussels (Mytilus galloprovincialis) during 2018-2019 in several mollusc production areas of Sardinia (Italy, western Mediterranean). Investigations of the presence and abundance of PST-producing microalgal species in marine water and of the toxins associated with shellfish were carried out concomitantly. Overall, the results suggested a spatio-temporal expansion of Alexandriumpacificum and Alexandriumminutum in recent years, with an increasing number of PSTs present in molluscs and increased occurrences of toxicity cases. Liquid chromatography with fluorescence detection determined the toxin profile to be composed primarily of the carbamate gonyautoxin-5 and N-sulphocarbamoyltoxins 1 and 2. The study highlights the potential high risk to consumers of poisoning by bivalve molluscs bred in Sardinia, where shellfish production is a very important industrial sector. For this reason, routine monitoring is strongly recommended in order to mitigate any harm to human health as well as negative socio-economic consequences.

Bacterial and Viral Investigations Combined with Determination of Phytoplankton and Algal Biotoxins in Mussels and Water from a Mediterranean Coastal Lagoon (Sardinia, Italy).

Calich Lagoon is a Mediterranean coastal lagoon located along the northwestern coast of Sardinia (Italy). The connection to marine and fresh water determines the high productivity of this coastal lagoon. Despite its great potential and the presence of natural beds of bivalve mollusks (Mytilus galloprovincialis), the lagoon has not yet been classified for shellfish production. In this study, through a multidisciplinary approach, the presence of several bacterial pathogens (Escherichia coli, Salmonella spp., and Vibrio spp.) and viral pathogens (hepatitis A virus and norovirus genogroups I and II) was evaluated from March 2017 to February 2018. In addition, phytoplankton composition in lagoon waters and associated algal biotoxins (paralytic and diarrhetic shellfish poisoning) in mussels were also monitored. The aim of this study was to provide useful data to improve knowledge about their seasonal presence and to assess the potential risk for public health, as well as to provide input for future conservation and management strategies. In mussels, Salmonella spp. were found in spring, along with E. coli, but Salmonella spp. were not found in autumn or winter, even though E. coli was detected in these seasons. Vibrio parahaemolyticus was found in autumn and winter, but not in spring. Norovirus genogroups I and II were found in winter samples. None of the bacteria were found in summer. Algal biotoxins have never been detected in mussel samples. Among potentially harmful phytoplankton, only Pseudo-nitzschia spp. were present, mainly in summer. The results showed that a possible bacterial and viral contamination, together with the presence of potentially toxic microalgae, is a real problem. Therefore, the development of natural resource management strategies is necessary to ensure the good quality of waters and guarantee the protection of consumers.

Epidemiological survey on the prevalence of Salmonella spp. in the Sardinian pig production chain, using real-time PCR screening method.

The aim of this study was to evaluate the prevalence of Salmonella spp. in the Sardinian pig production chain in order to establish the incidence of monophasic serovariant of Salmonella Typhimurium on isolates with molecular methods (real-time PCR and multiplex PCR). Samples were collected in three EC slaughterhouses, four small slaughterhouses annexed to farmhouses, one meat distribution center, four meat cutting laboratories and four sausage processing plants. A total of 166 samples were collected and analyzed: 46 environmental samples, 48 finishing pigs, 16 piglets, 24 samples of non-processed meat, 28 meat preparations and 4 meat products. All samples were processed with an initial screening using the real-time PCR MicroSEQ® Salmonella spp detection Kit (Applied biosystems, life technologies) and with the TaqMan® Real-time PCR to confirm the kit results. Samples that tested positive for Salmonella spp were confirmed with cultural method using the standard ISO 6579. Positive samples were submitted to phenotypic identification. One colony from each positive sample was serotyped with multiplex PCR method. Salmonella spp was isolated in 7 on 166 samples (4.22 %). Among the positive samples, two came from finishing pigs, two belonged to the category meat preparations, two to meat products, one was an environmental sample. Multiplex PCR confirmed that the collected strains belonged to the species Salmonella Typhimurium (1), Salmonella derby (3) and monophasic serovariant of Salmonella Typhimurium (3).

Toxoplasma gondii and Other Zoonotic Protozoans in Mediterranean Mussel ( Mytilus galloprovincialis) and Blue Mussel ( Mytilus edulis): A Food Safety Concern?

Mediterranean mussels ( Mytilus galloprovincialis) and blue mussels ( Mytilus edulis) are among the most consumed fishery products, but they are frequent vehicles of foodborne infection worldwide. In this study, we investigated the occurrence and seasonality of zoonotic protozoans in mussels farmed or sold at retail outlets in Italy. We collected and tested 1,440 M. galloprovincialis and 180 M. edulis. Pooled samples were molecularly tested for Giardia duodenalis, Cryptosporidium spp., and Toxoplasma gondii and then sequenced. Sixty-two (45.9%; 95% confidence interval, 37.5 to 54.3%) mussel pools tested positive for one or more of the investigated pathogens. Both Mytilus species and samples from all the investigated areas harbored pathogens. Mussels were statistically more contaminated by Cryptosporidium spp., followed by T. gondii and G. duodenalis assemblage A, and M. galloprovincialis was more contaminated than M. edulis ( P < 0.01). Contamination was more likely in mussels at retail outlets ( P < 0.05) than in those from farms and in mussels collected in spring ( P < 0.01) than in other seasons. This is the first report of T. gondii found in M. galloprovincialis in Italy and in M. edulis in Europe. The detection of zoonotic protozoans in a widely consumed food source indicates the need for a more detailed microbiological risk analysis, especially considering that bivalve mollusks are often consumed raw worldwide.

Detection of Dinophysis Species and Associated Okadaic Acid in Farmed Shellfish: a Two-year Study from The Western Mediterranean Area.

INTRODUCTION: Diarrhoetic shellfish poisoning (DSP), an alimentary intoxication known to lead to intestinal symptoms, and caused by toxins produced by some dinoflagellates (including several Dinophysis), represents a serious threat to public health. The aim of this paper was to provide information about the occurrence and abundance of potentially toxic harmful algal species causing DSP, and the associated concentration of okadaic acid (OA) toxins. The departing assumption was that in the study area there was an increase in the presence both of Dinophysis species and OA and its derivates that could result in a risk to the health of seafood consumers. MATERIAL AND METHODS: During 2015-2016, water and shellfish samples were collected in the Mediterranean area (Sardinia, Italy). Dinophysis cells were counted according to Utermöhl's method from water samples, while mass spectrometry was used to identify lipophilic toxins in molluscs. RESULTS: A total of 46 non-compliant samples of Mytilus galloprovincialis were observed. Their non-compliance concerned their OA levels above the legal limit. Among toxic dinoflagellates, D. acuminata and D. sacculus were the species found mostly during DSP events. CONCLUSION: No cases of human intoxication have been reported, but continuous surveillance of toxic phytoplankton is necessary to predict and prevent its harmful effects on human health.

Evaluation of short purification cycles in naturally contaminated Mediterranean mussels (Mytilus galloprovincialis) harvested in Sardinia (Italy).

The aim of the present study was to investigate the effect of short purification cycles on the safety of naturally contaminated Mytilus galloprovincialis from harvesting areas of the Gulf of Olbia (Sardinia, Italy). Samples from ten batches of mussels were collected before, during and after purification treatment at two purification centres (A-B). All the samples were analysed for Escherichia coli and Salmonella spp according to Council Regulation (EC) 2285/2015. Detection and enumeration of Vibrio spp were performed according to previously published methods. Presumptive identification of Vibrio spp isolates were performed by means of conventional biochemical tests and polymerase chain reaction. The presence of Hepatitis A virus was detected by nested reverse transcriptase-polymerase chain reaction. Environmental parameters (water temperature and salinity) were also recorded. The results of Escherichia coli counts showed the overall efficacy of the short purification cycles; a purification cycle of 8 h led to a rapid decline in the concentration. The decrease in Escherichia coli counts does not correlate with the presence of naturally occurring vibrios, the decline of which occurs at an even slower rate. The average contamination levels for Vibrio spp before purification were 8.20 ±â€¯0.47 and 7.99 ±â€¯0.62 Log10 CFU/g in samples collected at purification plants A and B, respectively. After purification, the average contamination levels were 8.10 ±â€¯0.60 Log10 CFU/g at purification plant A and 7.85 ±â€¯0.57 Log10 CFU/g at purification plant B. The contaminated samples revealed the presence of Vibrio alginolyticus (n=21), Vibrio fluvialis (n=12), Vibrio cholerae (n=4), Vibrio parahaemolyticus (n=2) and Vibrio vulnificus (n=1). The Vibrio parahaemolyticus isolates carried the tdh or the trh genes. None of the isolates was tdh+/trh+. Salmonella spp and Hepatitis A virus were not detected. The adoption of short purification cycles for Mytilus galloprovincialis in the presence of pathogenic vibrios might not be sufficient to guarantee the safety of consumers.

Correction: Occurrence of Harmful Algal Species and Shellfish Toxicity in Sardinia (Italy).

[This corrects the article on p. 6095 in vol. 5, PMID: 28058244.].

Yessotoxin detection in bivalve molluscs: A case study from coastal mussel farms (Sardinia, Italy).

This work reports the first communication relating to the presence of yessotoxins in Mytilus galloprovincialis from coastal mussel farms (Sardinia, western Mediterranean) detected during 2008 and 2013 through a monitoring programme. The paper emphasizes how the changes both in yessotoxin permitted limits and used methods, established by legislation, have influenced the interpretation of the obtained results. Consequently, the samples that resulted negative during 2008 would have been positive until August 2013 and negative from September 2013 up to now, and the samples that were positive in 2013 would have been positive in 2008 and negative nowadays, according to Regulation currently in force. Regular monitoring of biotoxins demonstrated that, although yessotoxins have been rarely present in the past in Sardinia, they may cause toxicity in shellfish. So, it's important to keep up on legislation's changing and laboratory methods.

Occurrence of Harmful Algal Species and Shellfish Toxicity in Sardinia (Italy).

Sardinia (Italy, north-western Mediterranean) is a commercially important producer of edible bivalve molluscs. Since the early 2000s, it was subjected to recurring cases of mussel farm closures due to toxic algal poison. Here, we present the studies on toxin concentrations and the associated potentially toxic phytoplankton distribution and abundances carried out by a regular monitoring programme in Sardinian shellfish areas, from January to May 2015. Diarrheic shellfish poisoning (DSP) toxins were detected in several bivalve molluscs samples, while paralytic shellfish poisoning (PSP) and paralytic shellfish poisoning toxins were present just once, without exceeding the legal limits. Potentially toxic algal species have been constantly present. Pseudo-nitzschia species were present during the entire study often with high abundances, while Dinophysis species reached high densities sporadically. Among PSP phytoplankton, only Alexandrium minutum Halim was found. The data obtained in this study showed an increase in the DSP toxicity in mussels in Sardinia. No clear relation between the occurrence of toxins in shellfish and the presence of potentially toxic algal species was found, although a slight correlation between DSP toxins and Dinophysis species could be supported.

Detection of Pathogenic Yersinia Enterocolitica in Slaughtered Pigs by Cultural Methods and Real-Time Polymerase Chain Reaction.

Healthy pigs carrying pathogenic to human Yersinia enterocolitica strains are the main source of entry into slaughterhouse, where cross-contamination of carcasses can happen. The aim of this work was to determine Y. enterocolitica prevalence in slaughtered pigs, investigating the presence of carriers in relation to carcass contamination. A total of 132 pig samples (tonsils, mesenteric lymph nodes, colon content, carcass surface) were collected from 4 Sardinian slaughterhouses. All the samples were examined by the ISO 10273:2003 method, and the prevalence was also determined by direct plating on CIN Agar. Moreover, to detect the ail positive Y. enterocolitica strains in enrichment broths and isolates a real-time polymerase chain reaction (PCR) was applied. Y. enterocolitica prevalence was 19% with direct plating and 12% with enrichment methods. Carcass surfaces and tonsils prevalence was 5.30% by direct plating, and 5.3% and 2.2%, respectively, by enrichment method. Tonsil samples showed an average contamination level of 3.2×103 CFU/g, while the mean value on carcass was 8.7×102 CFU/g. An overall prevalence of 9.8% of ail positive Y. enterocolitica broths was detected by RT-PCR, that found a higher prevalence in tonsils (7.5%) with respect to cultural methods, confirming the greater sensitivity of this technique when applied for tonsils and faeces samples. The results show a relatively low pathogenic Y. enterocolitica prevalence in pigs slaughtered in Sardinia. Good hygiene measures should be applied at slaughterhouse in order to prevent the entry of carriers and control carcass contamination.

Microbiological and Chemical Evaluation of Helix Spp. Snails from Local and Non-EU Markets, Utilised as Food in Sardinia.

With this study, 28 pools of snails of the genus Helix, respectively Helix aspersa (n=24) and Helix vermiculata (n=4) were analysed. They were taken from snail farming and stores. The snails were from Sardinia, other regions of Italy, and from abroad. All the samples were examined as pool looking for these microbiological target: Salmonella spp., Listeria monocytogenes, Escherichia coli O157, Clostridium perfringens, Norovirus and Hepatitis A Virus (HAV). In the same pools, the concentration of cadmium and lead by inductively coupled plasma mass spectrometry was also determined. The levels of these heavy metals were quite high, especially for cadmium. Two samples were positive for Salmonella spp., while no sample was positive for Escherichia coli O157, HAV and Norovirus. Two samples were positive for Clostridium perfringens and 8 for Listeria monocytogenes. The microrganisms related to Listeria monocytogenes were identified using biochemical techniques, then serotyped and gene sequenced by multiple loci sequence typing technique. Furthermore, antimicrobial restistence was tested on the same samples.

Verocytotoxin-producing Escherichia coli O26 in raw water buffalo (Bubalus bubalis) milk products in Italy.

Escherichia coli 026 is known as a verocytotoxin-producing E. coli (VTEC) organism that causes severe foodborne diseases such as hemorrhagic colitis and hemolytic uremic syndrome. Although cattle are the most important reservoir of VTEC, only a few reports on the role of water buffalo (Bubalus bubalis) as a reservoir of VTEC and on the presence of these organisms in their milk are available. However, in Southern Italy, where water buffalo are intensively reared, an outbreak of hemolytic uremic syndrome due to E. coli 026 has recently been reported, in which the consumption of typical dairy products was considered to be a common risk factor. The aims of this work were to assess the prevalence of E. coli O26 in raw water buffalo milk, to characterize the virulence gene profiles of the isolates, and to evaluate their phenotypic antimicrobial resistance pattern. Of 160 analyzed samples, 1 (0.6%) tested positive for E. coli O26, and the isolate showed the stx1+/stx2+/eae-/hlyA+ genotypic profile. The strain showed resistance against glycopeptides, macrolides, and penicillins. The presence of VTEC organisms in raw water buffalo milk could be considered to be a potential threat to consumers; however, the strict adherence to the processes used in the preparation of the most common buffalo dairy products could strongly mitigate the foodborne risk. To our knowledge, this article reports the first isolation and characterization of E. coli O26 VTEC in raw water buffalo milk.