Raffaele Marrone

Occurrence of antibiotic resistance in bacteria isolated from seawater organisms caught in Campania Region: preliminary study

BackgroundEnvironmental contamination by pharmaceuticals is a public health concern: drugs administered to humans and animals are excreted with urine or faeces and attend the sewage treatment. The main consequences of use and abuse of antibiotics is the development and diffusion of antibiotic resistance that has become a serious global problem. Aim of the study is to evaluate the presence of antimicrobial residues and to assess the antimicrobial resistance in bacteria species isolated from different wild caught seawater fish and fishery products.ResultsThree antibiotic substances (Oxytetracicline, Sulfamethoxazole and Trimethoprim) were detected (by screening and confirmatory methods) in Octopus vulgaris, Sepia officinalis and Thais haemastoma. All Vibrio strains isolated from fish were resistant to Vancomycin (VA) and Penicillin (P). In Vibrio alginolyticus, isolated in Octopus vulgaris, a resistance against 9 antibiotics was noted.ConclusionsWild caught seawater fish collected in Gulf of Salerno (Campania Region), especially in marine areas including mouths of streams, were contaminated with antibiotic-resistant bacteria strains and that they might play an important role in the spread of antibiotic-resistance.

New antimicrobial peptides against foodborne pathogens: From in silico design to experimental evidence

Recently there has been growing interest in the discovery of new antimicrobial agents to increase safety and shelf-life of food products. Here, we developed an innovative approach by introducing the concept that mitochondrial targeting peptides (MTP) can interact and disrupt bacterial membranes, acting as antimicrobial agents. As proof-of-principle, we used a multidisciplinary strategy by combining in silico predictions, docking simulations and antimicrobial assays, to identify two peptides, MTP1 and MTP2, which were structurally and functionally characterized. Both compounds appeared effective against Listeria monocytogenes, one of the most important foodborne pathogens. Specifically, a significant bactericidal activity was evidenced with EC50 values of 16.8±1.2μM for MTP1 and 109±7.0μM for MTP2. Finally, NMR structure determinations suggested that MTP1 would be oriented into the membrane bilayer, while the molecular shape of MTP2 could indicate porin-mediated antimicrobial mechanisms, as predicted using molecular docking analysis. Therefore, MTPs represent alternative sources to design new potential bio-preservatives.

Complete genome sequencing of a genotype 3 hepatitis E virus strain identified in a swine farm in Italy.

In this study, we investigated hepatitis E virus (HEV) infection in piglets sampled in two farms in southern Italy. The virus was detected in 11 out of 15 animals tested. Based on sequence analysis, the 6 Italian strains examined belonged to two clusters containing both swine and human strains of either genotype 3 subtype e or f from Europe and Japan. The two Italian strain clusters shared nucleotide identity of 81.8% and 87.5% in the ORF2 (capsid protein) and ORF1 (RdRp) diagnostic fragments, respectively, confirming the heterogeneity of genotype 3 viruses circulating in pigs in Italy. The complete genome of one genotype 3 subtype e strain and the full ORF2 and ORF3 coding regions of one of the genotype 3f strains, obtained in this study, were compared to other HEV sequences available on line (NCBI database). The results of analysis showed that porcine strains clustered together with human and swine strains detected in Europe. Most changes in the coding region corresponded to synonymous mutations, and only the ORF3 showed a positive selection. Further, analyses are needed to understand the clinical significance of HEV genotypes and subtypes.

Determination of nitrate and nitrite levels in infant foods marketed in Southern Italy

Nitrate and nitrite concentrations in foods have aroused considerable interest because of their possible toxicity to humans, especially younger children. Since dietary exposure to these compounds includes sources other than vegetables, 104 infant foods consisting of animal, plant and mixed origin and available on sale to the public were examined using the spectrophotometric AOAC method to assess whether during the weaning period the use of commercial follow-on formulas could be a cause of concern for exceeding the ADIs set at international level. Nitrate values (mg kg−1) ranged between 0.35 and 131.68, nitrite between 1.12 and 80.22. The highest mean values were found in foods of plant origin (45.5) for nitrate and in foods of mixed origin (12.48) for nitrite. Nitrate contents never exceeded the level of 200 mg kg−1 set by EC Regulation 1881/2006 whereas the ingestion of most of the samples would have been the reason for exceeding the ADI set for nitrites.

Biogenic amines profile in processed bluefin tuna (Thunnus thynnus) products

The aim of this study was to evaluate the behavior of biogenic amines (BAs), especially histamine (HIS), and its correlation with pH, water activity (Aw), sodium chloride (NaCl), and microbiological parameters in innovative bluefin tuna (Thunnus thynnus) – raw, salted, seasoned and cooked products. The sensory analysis showed that this seafood typology, especially the pressed and cooked products, could be accepted willingly by consumer. The results showed amine profile trends that are similar to those observed during ripening and seasoning of pig meat products; HIS levels were found to be lower than the limits set by EU legislation in all products and during the whole storage period. To ensure the safety of the analyzed products, despite using raw materials of excellent quality, it is important to select process parameters that reduce the BA production.

NMR and computational data of two novel antimicrobial peptides.

Here we report details on the design and conformational analysis of two novel peptides showing antimicrobial properties, as reported in the research article, “New antimicrobial peptides against foodborne pathogens: from in silico design to experimental evidence” G. Palmieri, M. Balestrieri, Y.T.R. Proroga, L. Falcigno, A. Facchiano, A. Riccio, F. Capuano, R. Marrone, G. Campanile, A. Anastasio (2016) [1]. NMR data, such as chemical shifts in two different solvents as well as aCH protons deviations from random coil values and NOE patterns, are shown together with the statistics of structural calculations. Strategy and particulars of molecular design are presented.

Monitoring of irradiated food products marketed in Italy and evaluation of electron spin resonance signal sensitivity of experimentally irradiated fish scales

Many countries, in order to authorise the use of food irradiation, claim the availability of methods to detect the occurred treatment in addition to the respect of safe use of this technology. Among physical methods, the electron spin resonance (ESR) measuring the number of free radicals that are formed during irradiation can be applied only to those foods with cellulose, a crystalline or bone structure, in which free radicals have a shelf life greater than irradiated product. The aim of this study was to highlight an irradiation treatment in European and extra-European foods marketed in Southern Italy by the means of ESR technique. Furthermore, in order to optimise the preparation procedures the efficacy of the above mentioned method in fish scales experimentally irradiated has been evaluated. From February to September 2012, a total number of 83 samples of food products of animal and plant origin were taken at the border inspection post and at retail market and finally analysed. At the same time, the scales of grouper and barracuda have been experimentally irradiated at 0.5 kGy and were subsequently analysed using ESR. Results showed 5 frog legs out of 83 samples positive for treatment and confirm the applicability of ESR also for fish scales.

Shelf life of different fish species stored with passive refrigeration (PRS).

ABSTRACT Shelf life of different fish species stored with passiverefrigeration (PRS) R. Marrone & L. Vollano & C. Chirollo & G. Palma & R. Mercogliano Published online: 10 July 2009 # Springer Science + Business Media B.V. 2009 Keywords Fishspecies.PRS.ShelflifeAbbreviationsPRS passive refrigeration systemQIM quality index methodTMA trimethylamineTVN total volatile nitrogenIntroductionPassive Refrigeration—PRS™- is a system developed for the preservation and transport ofperishable products. Passive Refrigeration—PRS™ technology is based on thermal accumu-lation (“Thermal Charge”) achieved through the freezing of eutectics obtained by circulatingcold brine when power is available and/or has a competitive price. After the initial “ThermalCharge” the fusion enthalpy provides the energy necessary to absorb the released heatprogressively and proportionally to requirements, maintaining optimal preservation conditionsfor the specified period (“Thermal Autonomy” from 2 up to 30 days or more) without furtheruse of energy and cooling groups. The large heat exchange surface and the minimum

Listeria monocytogenes biofilm production on food packaging materials submitted to physical treatment

Listeria monocytogenes (L.m.) is an agent of serious foodborne illness. It is a major concern for the food industry, since microorganism, growing in biofilms is protected against cleaning and disinfection and is difficult to eradicate. Aim of this study was to develop a protocol to assess the ability of two flexible packaging materials, named HGP40 and GND35, submitted to corona discharge treatment, to limit the production of L.m. biofilm at 12±1°C. Two strains were selected for this study: L.m ATCC 7644 and L. m. EURL 12MOB098LM isolated from dairy products. Results suggest that both L.m. strains were able to form biofilm on packaging materials tested. The differences on HGP40 and GND35s treated and not treated surfaces were not statistically significant.

Evaluation and comparison of four protein extraction protocols for mono- and two-dimensional electrophoresis in Mytilus galloprovincialis

In this study, four protein extraction protocols from Mytilus galloprovincialis were evaluated with the aim to identify the most practical, efficient and reproducible method. Four extraction protocols frequently used for mussels and organic matrices were selected and compared. The methods were based on the use of: i) TRIzol reagent; ii) Lysis buffer; iii) phenylmethanesulfonyl fluoride; iv) trichloroacetic acid-acetone. Protein concentration was measured by the Bradford method. Three specimens of mussels were studied and the analysis was conducted in triplicate for each of the four protocols. Results indicated that the four methods could extract significantly different protein profiles. The highest number of protein spots resolved in 2DE gels and the best reproducibility was obtained using trichloroacetic acid-acetone protocol. Results afforded the selection of a suitable extraction protocol to be used for ecotoxicoproteomics studies from mussels and for other proteomic studies conducted by particularly complex tissues such as Mytilus galloprovincialis.