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Concentrations of some toxic (Hg, Cd, Pb) and essential metals (Zn, Cu, Cr, Fe) relevant to human health were determined in different varieties of traditional cheeses, included in Traditional Agricultural Food Products (TAP) list, sampled in various farms in Apulia and Sicily, two regions of Southern Italy. Among toxic metals, Pb showed the highest concentrations (hard cheese: 0.13 μg g−1 w.w.; fresh cheese: 0.07 μg g−1 w.w.), while among essential element the most abundant was Fe (hard cheese: 2.86 μg g−1 w.w.; fresh cheese: 2.23 μg g−1 w.w.). In terms of food safety, the toxic metal concentrations in the majority of the samples investigated were below the maximum permitted levels set by several non-European countries, except for Pb showing levels notably exceeding in some hard cheese (0.22–0.37 μg g−1 w.w.). Also the estimated intakes of toxic metals remained far below the provisional tolerable intakes and consequently no health risk is expected from the consumption of these cheeses. However, for greater food safety, besides to a continuous surveillance it would be advisable to establish maximum limits for metals either in milk or products made of milk.

Verocytotoxin-producing Escherichia coli (VTEC) O26 is an emergent pathotype that has caused an increasing number of sporadic cases and outbreaks of gastroenteritis, hemorrhagic colitis, and hemolytic uremic syndrome in the United States and Europe. Many cases are associated with the consumption of milk and undercooked or fermented meats. The stx(2) strains of VTEC O26 seem to be more likely to cause human infections than isolates expressing only stx(1). The isolation and identification of VTEC O26 from foods is labor intensive and time-consuming. We developed a multiplex PCR (M-PCR) assay for the identification and characterization of E. coli O26 VTEC and its detection in raw milk and ground beef. The method is based on the amplification of the wzx, stx(1), and stx(2) genes for the simultaneous detection of the O26 antigen and verocytotoxin types 1 and 2. This M-PCR assay had a sensitivity of 10(8) CFU/ml when applied to a bacterial suspension and of 10(6) CFU/ml or g when applied to both inoculated milk and minced beef samples. This M-PCR assay also was highly specific, and results were consistently negative for negative controls (nonpathogenic E. coli strains, uninoculated milk and beef samples, and samples inoculated with the nontarget microorganisms). This method could be used for the rapid detection of E. coli O26 VTEC from foods and for the rapid identification and characterization of clinical and environmental isolates.

Helicobacter pylori is an organism widespread in the human population and sometimes responsible for serious illnesses. Since H. pylori has been detected in Italy from an high percentage of sheep milk samples, it has been hypothesized that contaminated milk, may act as a vehicle of transmission of the microorganism to humans. In this work, a Nested Polymerase Chain Reaction approach has been used to detect H. pylori phosphoglucosamine mutase gene (glmM) from sheep, goat and cow milk artificially contaminated with wild H. pylori strains isolated from human gastric biopsies and the reference strain (H. pylori ATCC 43504). The technique showed a high sensitivity of 3 CFU/ml and proved to be both specific and rapid, The authors suggest that it could be used as a sensitive method for a rapid screening of sheep, goat and cow milk samples during the microbiological control of these large consumed foods.

Verocytotoxin-producing Escherichia coli (VTEC) non-O157 serogroups are among the most important emerging food-borne pathogen groups. In particular, the O26 serogroup is able to cause a large spectrum of illnesses in humans which have a significant public health impact as they may range from haemorrhagic colitis (HC) to haemolytic uremic syndrome (HUS) and thrombotic thrombocytopenic purpura (TTP). It is known that VTEC organisms are associated with animal reservoirs, i.e. ruminants, and foods of animal origin, especially undercooked meat and raw milk, are often involved in outbreaks. In this study, 250 minced beef samples collected at retail outlets in southern Italy were tested for the presence of E. coli O26 and the isolates were characterized and studied for their antimicrobial resistance properties. Three minced beef samples (1.2%) tested positive for E. coli O26; one isolate per positive sample was characterized. One isolate harboured the genes encoding for virulence factors intimin (eaeA) and enterohaemolysin (hlyA), while none presented verocytotoxin-encoding genes (stx1 and stx2) and all were negative at the verotoxicity assay. All the isolates showed resistance properties to at least four antimicrobial agents tested and two were multi-drug resistant (MDR). Although no verocytotoxin-encoding genes were found in the isolates, the presence of potentially pathogenic E. coli O26 strains in minced beef points to the need for proper hygiene during meat production to reduce the risk of food-borne illnesses and transmission of MDR organisms via foods to humans. This paper is the first report on the presence and characterization of E. coli O26 in minced beef marketed in Italy.

Helicobacter pylori (H. pylori) is a very important bacterial pathogen of humans which may cause gastrointestinal illnesses ranging from gastric and duodenal ulcers to neoplastic diseases such as MALToma and gastric cancer. Transmission via contaminated food is still uncertain but several authors believe this can realistically occur and milk may act as a vehicle of infection. This paper reports the results of H. pylori survival trials in pasteurized and ultrahigh temperature (UHT) milks artificially contaminated and aerobically stored at 4 degrees C. The results obtained showed that the four strains used in this study (H. pylori nat 18-19-20 and H. pylori ATCC 43504), had a progressive reduction in bacterial load with a median survival of 9 days in pasteurized milk and 12 days in UHT milk, with approximate average of initial inoculum of 10(5) and 10(6)cfu/ml, respectively. These findings are very important to clarify the route of transmission of H. pylori to humans via food and for implementation of a correct risk analysis for food safety purposes.

Staphylococcus aureus is considered to be one of the leading causes of food-borne illnesses. Milk, dairy products and meats are often contaminated with enterotoxigenic strains of this bacterium. Foodstuff contamination may occur directly from infected food-producing animals or may result from poor hygiene during production processes, or the retail and storage of foods, since humans may carry the microorganism. The number of S. aureus strains that exhibits antimicrobial-resistance properties has increased, together with the potential risk of transmitting the same properties to the human microflora via foods or inducing infections hard to be treated. This paper reports the results of a 3-year survey (2003-2005) on the occurrence of S. aureus in meat and dairy products. Of 1634 samples examined, 209 (12.8%) were contaminated with S. aureus. A total of 125 enterotoxigenic S. aureus strains were biotyped and their antimicrobial resistance pattern tested. Most of the isolated strains produced SED (33.6%), followed by SEA (18.4%), SEC (15.2%), SEB (6.4%) and belonged mainly to the Human ecovar (50.4%), followed by Ovine (23.2%), Non-Host-Specific (17.6%), Bovine (7.2%) and Poultry-like (1.6%) ecovars. Finally, the 68.8% analysed strains showed antimicrobial resistance properties at least at one of antibiotics tested. Human biotype showed antimicrobial resistance at more than one antibiotic than the other biotypes (p

Mytilus galloprovincialis is one of the most commonly consumed of all bivalve molluscs. The consumption of raw bivalve molluscs has caused outbreaks of food poisoning due to Vibrio parahaemolyticus and Vibrio vulnificus. This paper reports the results of a survey on the presence of V. parahaemolyticus, V. vulnificus fecal coliform bacteria, Escherichia coli and Salmonella spp. in 600 M. galloprovincialis samples collected from retail outlets in the Puglia region. V. parahaemolyticus and V. vulnificus were found in 47 (7.83%) and 17 (2.83%) of the samples, respectively. One sample (0.16%) was contaminated with Salmonella spp. but no relationship was observed between vibrios and fecal coliforms and E. coli. There were no significant differences among vibrios present in bivalve molluscs during the 3-year survey.

Staphylococcus aureus is a very common organism capable of producing several enterotoxins (SEs) that cause intoxication symptoms of varying intensity in humans when ingested through contaminated food. This paper reports the results of an investigation on the presence of Coagulase-Positive Staphylococci (CPS) and S. aureus in several food products marketed in Italy and on food contact surface swabs sampled from the food industry. A total of 11,384 samples were examined and 1971 of them (17.3%) were found to contain CPS. The assays performed on 541 CPS strains led to the identification of 537 S. aureus strains on which characterization of type A, B, C and D staphylococcal enterotoxins (SEA, SEB, SEC and SED) was performed. A total of 298 S. aureus strains (55.5%) produced one or more SEs: 33.9% of the strains produced SEC, 26.5% SEA, 20.5% SEA+SED, 13.4% SED, 2.7% SEB, 1.7% SEA+SEB, 0.7% SEC+SED and 0.3% produced SEA+SEC and SEB+SEC. The investigation highlighted that these organisms are very common and constitute a potential risk for consumers' health.

E. coli O157 is a foodborne pathogen responsible for serious human illnesses, such as hemorrhagic colitic and hemolytic uremic syndrome. Ground beef products are among the foods that are more commonly contaminated, and the strains isolated have been frequently found to carry virulence factors of this pathotype. This paper reports the results of serotyping assays and of investigations performed to screen for virulence factors of 10 E. coli O157 strains isolated from fresh sausages purchased at retail meat outlets in various provinces of Apulia (southern Italy). The presence of verocytotoxins was assessed on VERO cells and ELISA tests. Multiplex PCR assays were performed for the eae, stx1, stx2 and hlyA genes. Six of the 10 strains examined presented the H7 antigen and all of them proved to be potentially pathogenic due to the presence of individual or multiple virulence factors.