Phage Inactivation of Listeria monocytogenes on San Daniele Dry-Cured Ham and Elimination of Biofilms from Equipment and Working Environments

The anti-listerial activity of generally recognized as safe (GRAS) bacteriophage Listex P100 (phage P100) was demonstrated in broths and on the surface of slices of dry-cured ham against 5 strains or serotypes (i.e., Scott A, 1/2a, 1/2b, and 4b) of Listeria monocytogenes. In a broth model system, phage P100 at a concentration equal to or greater than 7 log PFU/mL completely inhibited 2 log CFU/cm2 or 3 log CFU/cm2 of L. monocytogenes growth at 30 \ub0C. The temperature (4, 10, 20 \ub0C) seemed to influence P100 activity; the best results were obtained at 4 \ub0C. On dry-cured ham slices, a P100 concentration ranging from 5 to 8 log PFU/cm2 was required to obtain a significant reduction in L. monocytogenes. At 4, 10, and 20 \ub0C, an inoculum of 8 log PFU/cm2 was required to completely eliminate 2 log L. monocytogenes/cm2 and to reach the absence in 25 g product according to USA food law. Conversely, it was impossible to completely eradicate L. monocytogenes with an inoculum of approximately of 3.0 and 4.0 log CFU/cm2 and with a P100 inoculum ranging from 1 to 7 log PFU/cm2. P100 remained stable on dry-cured ham slices over a 14-day storage period, with only a marginal loss of 0.2 log PFU/cm2 from an initial phage treatment of approximately 8 log PFU/cm2. Moreover, phage P100 eliminated free L. monocytogenes cells and biofilms on the machinery surfaces used for dry-cured ham production. These findings demonstrate that the GRAS bacteriophage Listex P100 at level of 8 log PFU/cm2 is listericidal and useful for reducing the L. monocytogenes concentration or eradicating the bacteria from dry-cured ham

Seasonal variation in nitrogen isotopic composition of bog plant litter during 3years of field decomposition

In this study, we describe the seasonal variation in 15N abundance in the litter of two Sphagnum species and four vascular plant species during 3years of field decomposition in an Italian Alpine bog. Litter bags were periodically retrieved at the end of summer and winter periods, and the δ15N in residual litter was related to mass loss, litter chemistry, and climatic conditions. In Sphagnum litter, higher rates of decomposition during summer months were associated with an increase of δ15N probably due to the incorporation of microbial organic compounds rich in 15N. The litter of Eriophorum vaginatum and Carex rostrata was characterized by a decrease of δ15N, so that the final signature was significantly lower than in initial litter. On the other hand, the residual litter of Potentilla erecta and Calluna vulgaris was characterized by a final δ15N higher than in initial litter. Our data reported a seasonality of 15N abundance in the residual litter of Sphagnum species, but not in that of vascular plant species, thus highlighting the role of differences in litter chemistr

Sulfur and oxygen isotope compositions of Upper Triassic sulfates from northern Apennines (Italy) : paleogeographic and hydrogeochemical implications

Upper Triassic bedded evaporite sulfate of the Burano Formation outcropping at Cerreto Pass between Tuscany and Emilia-Romagna in the Northern Apennines were analyzed for sulfur and oxygen isotope compositions, yielding d34S and d18O values of 15.5±0.4‰ and 10.8±1.2‰, respectively (mean ±99% confidence intervals). Combining these values with those of other Burano Formation sulfate deposits along the Apennine chain, mean for d34S and d18O values are obtained (15.2±0.2‰ and 10.9±0.5‰, respectively). These isotopic signatures are interpreted as preserved primary features, despite the fact that the Burano Formation underwent anchizone to epizone metamorphism during the Apennine orogenesis. An overall d18O value of 10.9±1.5‰ (mean ± pooled standard deviation), obtained by combining consistent sets of data from Italy and Spain, closely approaches that of gypsum deposited from the Tethys ocean during the Late Triassic. In addition, reviewing the isotope data published on Late Triassic evaporite sulfates from the Mediterranean area and abroad, several d34S values appear to be lower than the inferred primary isotopic signature, and seemly decrease from East to West in the Mediterranean region, suggesting a similar trend for the Tethys ocean sulfate. Possibly, 34S-depleted sulfate entered the ocean through oxidation of volcanic SO2 emitted in the atmosphere and degassed from the seafloor during the development of Late Triassic rifting. On the other hand, positive shifts of d34S and d18O values also occur, defining a common trend that may be related to synsedimentary biological effects or post-depositional metasomatic-metamorphic effects, the latter affecting particularly the d18O signature. Therefore, the d34S and d18O signatures of evaporite sulfate may provide a like "slide-rule" diagram to distinguish between isotopic effects related to biological or abiological processes, thus contributing to the reconstruction of paleoenvironments and paleogeographic settings. Based on the d34S-d18O "slide-rule", the isotopic composition of sulfate dissolved in spring and stream waters of northern Tuscany was interpreted in terms of origin of the sulfate and modifying processes in solution. It was concluded that sulfate in springs derives from Upper Triassic evaporite existing locally at depth (Burano Formation), whereas sulfate in streams is manifestly a mixture of Burano Formation sulfate with supergene sulfate from oxidation of sulfide in the rocks. In sulfurous springs, both sulfur and oxygen isotope fractionations with respect to the source sulfate signatures may be ascribed to bacterial effects. However, the oxygen isotope exchange of sulfate with water should have been a very minor process as supported by the nearsurface temperature values estimated by sulfate-water oxygen isotope thermometry

Processing fresh mussels (M. galloprovincialis) by sous vide technology: effect on the microbiological characteristics

Sous-vide cook-chilled (SVCC) is used to describe food that has been vacuum-packed and given mild heat treatment under controlled conditions of time and temperature and subsequently rapidly cooled and stored at chilled conditions until heated before serving (Rhodehamel, 1992; Hansen et al., 1995). Limited studies reported the application of this process in aquacultural products (Espinosa et al., 2016; Shakila et al., 2009), such as trout fillets (Gonzalez-Fandos et al., 2004), 2009) and carp (Can, 2011) and there are no reports on the opportunities to apply such process to molluscs. The aim of the present research was to test the effect of the application of the SVCC technique on fresh mussel microbiological characteristics. Commercial Mediterranean mussels (M. galloprovincialis) were individually inoculated with 100 \ub5l suspension of Pseudomonas spp.(107 UFC/mL), packaged in a Oriented Polyamide/Polypropylene (OPA/PP, Orved S.p.A., Musile di Piave, VE, Italy) pouch and heat-sealed before being submitted to heat treatment in a steam oven (Lanoix Ali S.p.A., Treviso, Italy). After treatment, mussel pouches were immediately chilled at 3\ub0C. Six different time temperature combinations (75/85/95 \ub0C for 10 and 30 min), were tested in triplicate (3 specimens/group) and compared to raw and inoculated mussels. Total aerobic bacterial count (TBC), lactic acid bacteria (LAB), anaerobic sulphite-reducing clostridia, Pseudomonas spp. and pH were determined. All time/temperature combinations resulted in a substantial reduction of the Pseudomonas spp. population (<1 log CFU/g) both in raw (4.9 log CFU/g) and experimentally inoculated (5.7 log CFU/g) mussels. The homogenate pH values (6.22) resulted not affected by the heat treatment. Such results were confirmed on natural bacterial load of mussel. A TBC reduction (2.4 log and 3,5 log, respectively) was registered after treatment at 85 \ub0C both for 10 and 30 min, while the highest reduction (4.8 log) was observed at 95 \ub0C for 10 min confirming the efficacy of sous vide cook treatments even for fresh mussels. The technological and sensorial traits, as well the stability of these products both under refrigeration and thermal abuse conditions during storage need to be evaluated

OLED-based DNA biochip for Campylobacter spp. detection in poultry meat samples

Integrated biochips are the ideal solution for producing portable diagnostic systems that uncouple diagnosis from centralized laboratories. These portable devices exploit a multi-disciplinary approach, are cost effective and have several advantages including broader accessibility, high sensitivity, quick test results and ease of use. The application of such a device in food safety is considered in this paper. Fluorescence detection of a specific biological probe excited by an optical source is one of the most commonly used methods for quantitative analysis on biochips. In this study, we designed and characterized a miniaturized, highly-sensitive DNA biochip based on a deep-blue organic light-emitting diode. The molecular design of the diode was optimized to excite a fluorophore-conjugated DNA probe and tested using real meat samples to obtain a high sensitivity and specificity against one of the most common poultry meat contaminants: Campylobacter spp. Real samples were analyzed also by classical plate methods and molecular methods to validate the results obtained by the new DNA-biochip. The high sensitivity obtained by the OLED based biochip (0.37 ng/mu l) and the short time required for the results (about 24 h) indicate the usefulness of the syste

Identification and Estimation of Clinical Indices Useful for the Diagnosis of Melanoma from Macroscopic Images

openMelanoma is an extremely aggressive form of skin cancer. When not promptly detected and treated, it can quickly metastasize, leading to unfavourable prognostic outcomes. Achieving early melanoma diagnosis relies heavily on accurate and thorough skin analysis, made by an expert dermatologist. To address subjective judgments and time-expensive exams, a novel screening and diagnostic method utilising photogrammetry-derived images of skin lesions has been devised. This innovative approach is based on the acquisition of macroscopic images, depicting a large portion of the patient body, and enables the creation of a three-dimensional model of the patient, allowing for the extraction of corresponding images of each individual lesion. This thesis aims to quantitatively assess the asymmetry, the irregularity of the border and the color of skin lesions through the analysis of segmented macroscopic images, contributing to the development of an automated diagnostic tool useful to the clinician for melanoma identification. The analysis was conducted on a dataset comprising images of healthy skin lesions and lesions reported as suspicious by dermatologists among which nine cases were confirmed as melanomas by biopsy. By utilizing algorithms to objectively compute asymmetry and border irregularity parameters, coupled with an in-depth analysis of color features associated with melanocytic lesions, the investigation unveiled statistically significant differences in these attributes between benign and suspicious lesions. Indeed, statistical tests confirmed distinctive distributions of these parameters between the two skin lesion populations. These findings underscore the potential of automated diagnostic tools derived from macroscopic images in effectively identifying suspicious lesions, thus contributing to early melanoma detection strategies

Isotope analyses to explore diet and mobility in a medieval Muslim population at Tauste (NE Spain)

The Islamic necropolis discovered in Tauste (Zaragoza, Spain) is the only evidence that a large Muslim community lived in the area between the 8th and 10th centuries. A multi-isotope approach has been used to investigate the mobility and diet of this medieval Muslim population living in a shifting frontier region. Thirty-one individuals were analyzed to determine δ15N, δ13C, δ18O and 87Sr/86Sr composition. A combination of strontium and oxygen isotope analysis indicated that most individuals were of local origin although three females and two males were non-local. The non-local males would be from a warmer zone whereas two of the females would be from a more mountainous geographical region and the third from a geologically-different area. The extremely high δ15N baseline at Tauste was due to bedrock composition (gypsum and salt). High individual δ15N values were related to the manuring effect and consumption of fish. Adult males were the most privileged members of society in the medieval Muslim world and, as isotope data reflected, consumed more animal proteins than females and young males. © 2017 Guede et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Microbial quality of raw and ready-to-eat mung bean sprouts produced in Italy

The aim of this study was to determine the microbial quality of mung bean sprouts produced in Italy. The presence of pathogenic microorganisms (Shiga toxin- producing Escherichia coli (STEC), Salmonella spp. and Listeria monocytogenes), total coliforms, and total viable counts (TVCs) were determined. The study covered five years of sprout production. The results demonstrated that no pathogenic microorganisms were present, and the microbial load was less than 6 log CFU/g. The mung bean sprouts currently produced in Italy were found to be acceptable for consumption. An additional aim was to determine the fate of different strains of STEC, L. monocytogenes and Salmonella spp. by intentionally inoculating mung bean seeds during sprouting and by using chlorinated water to reduce the concentration of these strains in seeds and sprouts. The data demonstrated that these strains increased over 5\u20136 log CFU/g within 3 days from inocula. The chlorinated washing solution reduced the concentration of the investigated strains in seeds and sprouts by approximately 3 and 7 log CFU/g, respectively. However, it was not possible to completely eliminate the pathogens from either the mung bean seeds or sprouts. Despite these encouraging results, the producer's attention to hygienic quality should not be reduced when attempting to produce safe-to-consume mung bean sprouts