Giuseppina Tantillo

Antifungal activity of polymer-based copper nanocomposite coatings

Eukaryotes, such as fungi, can be harmful pathogen agents, and the control of their bioactivity is critical as humans are eukaryote organisms, too. Here, copper∕polymer nanocomposites are proposed as antifungal spinnable coatings with controlled copper-releasing properties. The tests of the bioactivity show that fungal growth is inhibited on the nanocomposite-coated plates, and the antifungal activity can be modulated by controlling the Cu nanoparticle loading.

A collagenase-targeted multiplex PCR assay for identification of Vibrio alginolyticus, Vibrio cholerae, and Vibrio parahaemolyticus.

A multiplex PCR assay using three collagenase-targeted primer pairs for the species-specific detection of Vibrio alginolyticus, Vibrio cholerae, and Vibrio parahaemolyticus was developed. The results highlight the species specificity of the three primer sets designed. Because of the increasing importance of Vibrio spp. in human foodborne diseases, molecular approaches for routine microbial screening and monitoring of clinical, environmental, and food samples also have become more important. The results of this study indicate that the gene coding for collagenase should be used as an alternative molecular target to discriminate among the three Vibrio species.

Updated perspectives on emerging vibrios associated with human infections

This review describes the ecological, clinical and epidemiological features of emerging vibrios and discusses what laboratory methods are being used for the detection of pathogenic vibrios in clinical, environmental and food samples. After selecting articles illustrative of the current scientific research on pathogenic vibrios, the review focuses on the need for better insight into the risk factors of emerging infections to establish adequate prevention procedures.

DNA barcoding for detecting market substitution in salted cod fillets and battered cod chunks.

The Italian Ministry of Agricultural, Food and Forestry Policies (MiPAAF) Decree dated 31 January 2008, which reports the Italian name for fish species of commercial interest, establishes that baccalà can be obtained exclusively from G. macrocephalus (Pacific cod) and G. morhua (Atlantic cod). This paper describes the COI-based DNA identification system to verify the substitution or misbranding of gadoid fish species and, consequently, its concordance with the labels on salted cod fillets shown as baccalà and on battered cod chunks labelled as bocconcini di baccalà. The analysis of interpretable sequences revealed that 55/65 dried salted cod fillet samples were detected as belonging to the family Gadidae, while 10/65 samples appeared to belong to the Lotidae family, while among battered cod chunks labelled as bocconcini di baccalà, the post-sequencing data analysis shows that the labels were completely wrong, with 28/40 samples from Pollachius virens and 12/40 samples from Brosme brosme. The substitution rate for products labelled on the market as baccalà in this study raises significant issues relating to food safety and consumer protection.

Norovirus in retail shellfish

Norovirus is a common cause of gastroenteritis outbreaks associated with consumption of raw shellfish. The majority of norovirus infections worldwide are due to genogroup II noroviruses. Bivalve molluscs (mussels, clams and oysters) at the end of the commercial chain, the points of purchase, were sampled between 2005 and 2008 in several retail points in Apulia, Italy, and screened by a semi-nested RT-PCR specific for genogroup II noroviruses. Noroviral RNA was detected in 12.1% of the samples, with lower frequency being observed in samples obtained from hypermarkets (8.1%) rather than in samples from open-air markets and fish shops (17.6% and 16.2%, respectively). By sequence analysis, the strains were characterized as norovirus variants GII.4/2004 and GII.b/Hilversum, which were both circulating in Italy in the same time-span.

Ciprofloxacin-modified electrosynthesized hydrogel coatings to prevent titanium-implant-associated infections

New promising and versatile materials for the development of in situ sustained release systems consisting of thin films of either poly(2-hydroxyethyl methacrylate) or a copolymer based on poly(ethylene-glycol diacrylate) and acrylic acid were investigated. These polymers were electrosynthesized directly on titanium substrates and loaded with ciprofloxacin (CIP) either during or after the synthesis step. X-ray photoelectron spectroscopy was used to check the CIP entrapment efficiency as well as its surface availability in the hydrogel films, while high-performance liquid chromatography was employed to assess the release property of the films and to quantify the amount of CIP released by the coatings. These systems were then tested to evaluate the in vitro inhibition of methicillin-resistant Staphylococcus aureus (MRSA) growth. Moreover, a model equation is proposed which can easily correlate the diameter of the inhibition haloes with the amount of antibiotic released. Finally, MG63 human osteoblast-like cells were employed to assess the biocompatibility of CIP-modified hydrogel coatings.

Detection of hepatitis A virus in shellfish (Mytilus galloprovincialis) with RT-PCR

A PCR assay for the detection of hepatitis A virus (HAV) in shellfish is described. The procedure involves the concentration of viral particles with the use of polyethylene glycol (PEG), followed by viral RNA extraction and purification with oligo(dT) cellulose. Reverse transcriptase-PCR detection was accomplished in a single step with the use of primers specific for the VP3-VP1 region of the genome. The procedure detected one 50% tissue culture infective dose (0.6 PFU) per 25 g of shellfish homogenate. Heminested PCR was then carried out to verify the specificity of the PCR products. The method was used to detect HAV in shellfish samples from EU categories B and C and to evaluate the quality of shellfish in routine monitoring for HAV in view of the relevant public health implications of this foodborne disease.

Polymerase chain reaction for the direct detection of Brucella spp. in milk and cheese.

A polymerase chain reaction test was developed to detect Brucella spp. directly in milk and cheese and optimized using primers for the BSCP-31 gene. A total of 46 cheese samples produced with sheep and goats milk were assayed, and Brucella spp. was detected in 46% of them, especially in cheese made from sheep milk. This method is of remarkable epidemiologic interest because it is an indirect test indicating the sanitary quality of milk used in dairy industries. The method showed good sensitivity and specificity. It is faster and less expensive than the conventional bacteriological assays.

Assessment of Dietary Intake of Patulin from Baby Foods

Patulin is a mycotoxin produced by microscopic fungi belonging to the Penicillium and Aspergillus genera, frequently detectable in moldy fruits and their derivatives fruit products. The EC Regulation 1881/06 has imposed the limit for the presence of patulin equal to 10 μg/kg or 10 μg/L in baby food on the basis of a PMTDI of 0.4 μg/kg bw set by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). A total of 120 homogenized baby foods were analyzed to evaluate the exposure of baby and children to patulin through the consumption of these products. None of examined samples has shown a toxin concentration above the limit imposed by the law, however a PAT concentration equal to 9 μg/kg was found in 22 samples, slightly below the fixed limit. The presence of patulin in marketed baby food can be regarded as a parameter indicative of the quality of raw materials used.

Occurence of potentially enterotoxigenic Bacillus cereus in infant milk powder

Considering that powdered infant milk formula effectively supports the growth of numerous pathogens, this study investigates the prevalence of potentially pathogenic Bacillus cereus in dried milk products by evaluating the occurrence of B. cereus and the presence of virulence-associated genes. The approach consisted of enriching, isolating and biochemical identifying isolates, followed by PCR assays aimed at the hbl (C, D, A, B), nhe (A, B, C) and cytK enterotoxin genes coding HBL complex, NHE complex and cytotoxin K, respectively. Among cytK-positive strains, the discrimination of two different forms for cytotoxin K, cytK-1 and cytK-2 was performed. Bacillus cereus was detected in powdered infant milk formula samples. All the strains harbored at least one gene of the cytK, HBL and NHE enterotoxins. Because of an increasing trend in invasive infections by B. cereus in infants and immunocompromised children, our PCR findings highlight the need to implement an adequate control plan in order to guarantee the health of potentially fragile consumers. From a hygiene point of view, intensive and continuous monitoring of potentially pathogenic B. cereus may be crucial for powdered infant milk formula safety and even recommended in order to assess the infant health risk, as proposed by Commission Regulation (EC) no. 1441/2007 on microbiological criteria for foodstuffs. Furthermore, the detection in this study of B. licheniformis, B. subtilis and B. mycoides strains raises significant health issues regarding Bacillus spp. in powdered infant milk formula.