Personalized computational electro-mechanics simulations to optimize cardiac resynchronization therapy.

In this study, we present a computational framework designed to evaluate virtual scenarios of cardiac resynchronization therapy (CRT) and compare their effectiveness based on relevant clinical biomarkers. Our approach involves electro-mechanical numerical simulations personalized, for patients with left bundle branch block, by means of a calibration obtained using data from Electro-Anatomical Mapping System (EAMS) measures acquired by cardiologists during the CRT procedure, as well as ventricular pressures and volumes, both obtained pre-implantation. We validate the calibration by using EAMS data coming from right pacing conditions. Three patients with fibrosis and three without are considered to explore various conditions. Our virtual scenarios consist of personalized numerical experiments, incorporating different positions of the left electrode along reconstructed epicardial veins; different locations of the right electrode; different ventriculo-ventricular delays. The aim is to offer a comprehensive tool capable of optimizing CRT efficiency for individual patients. We provide preliminary answers on optimal electrode placement and delay, by computing some relevant biomarkers such as d P / d t max , ejection fraction, stroke work. From our numerical experiments, we found that the latest activated segment during sinus rhythm is an effective choice for the non-fibrotic cases for the location of the left electrode. Also, our results showed that the activation of the right electrode before the left one seems to improve the CRT performance for the non-fibrotic cases. Last, we found that the CRT performance seems to improve by positioning the right electrode halfway between the base and the apex. This work is on the line of computational works for the study of CRT and introduces new features in the field, such as the presence of the epicardial veins and the movement of the right electrode. All these studies from the different research groups can in future synergistically flow together in the development of a tool which clinicians could use during the procedure to have quantitative information about the patient's propagation in different scenarios.

Leuconostoc gelidum Is the Major Species Responsible for the Spoilage of Cooked Sausage Packaged in a Modified Atmosphere, and Hop Extract Is the Best Inhibitor Tested.

Cooked sausages packaged in a modified atmosphere (MAP: 20% CO2, 70% N2, <0.2% O2) with evident yellow stains were analyzed. The aims of this work were to study the microbial cause of the spoilage and to evaluate different antimicrobial compounds to prevent it. Leuconostoc gelidum was identified as the primary cause of the yellow coating in spoiled cooked sausage, as confirmed by its intentional inoculation on slices of unspoiled sausage. Leuconostoc gelidum was the main bacteria responsible for the yellow coating in spoiled cooked sausage, as confirmed by its intentional inoculation on slices of unspoiled sausage. The yellow color was also evident during growth in the model system containing cooked sausage extract, but the colonies on MRS agar appeared white, demonstrating that the food substrate stimulated the production of the yellow pigment. The spoilage was also characterized by different volatile compounds, including ketones, ethanol, acetic acid, and ethyl acetate, found in the spoiled cooked sausage packages. These compounds explained the activity of Leuc. gelidum because they are typical of heterofermentative LAB, cultivated either on food substrates or in artificial broths. Leuc. gelidum also produced slight swelling in the spoiled packages. The efficacy of different antimicrobials was assessed in model systems composed of cooked sausage extract with the antimicrobials added at food product concentrations. The data showed that sodium lactate, sodium acetate, and a combination of sodium lactate and sodium diacetate could only slow the growth of the spoiler-they could not stop it from occurring. Conversely, hop extract inhibited Leuc. gelidum, showing a minimal inhibitory concentration (MIC) of approximately 0.008 mg CAE/mL in synthetic broth and 4 mg CAE/kg in cooked sausage slices. Adding hop extract at the MIC did not allow Leuc. gelidum growth and did not change the sensorial characteristics of the cooked sausages. To our knowledge, this is the first report of the antimicrobial activities of hop extracts against Leuc. gelidum either in vitro or in vivo.

Microbiological and physicochemical profile of Italian steak tartare and predicting growth potential of Listeria monocytogenes.

In the present study, growth potential of Listeria monocytogenes in steak tartare samples taken at retail and belonging to 13 brands marketed in Northern Italy was investigated. The samples were submitted to microbiological and chemical-physical characterization. The data obtained were used as inputs for the application of the predictive microbiology software FSSP that allows the estimation of the growth of L. monocytogenes during the shelf-life. Lactic acid bacteria, the main component of the microflora, gave variable counts among the brands (from 3.38 to 6.24 log CFU/g). pH and aw values were always higher than 5.3 and 0.96, respectively, thus they could not be considered as single efficient hurdles to prevent the growth of L. monocytogenes according to the EC Reg. 2073/2005; the same was observed for salt content (constantly <2 %) and nitrites (not quantifiable in all the samples, even if declared in some labels). Nevertheless, the combination of all the hurdles, evaluated by predictive microbiology using critical development factors, resulted in an estimated growth <0.5 log CFU/g throughout the shelf life; this output allowed us to consider all the steak tartare analysed as unfavourable substrate for L. monocytogenes growth. The information obtained could be useful for tartare producers as well as for competent authority to evaluate the effective risk concerning these typology of products.

Shelf-life of sheep arrosticini packaged in protective atmosphere.

The aim of this study was to evaluate the shelf-life of pre-packaged sheep's arrosticini produced in a factory located in northern Italy. Samples were divided into two series and packaged in modified atmosphere with specific gas mixtures: conventional (C: 35% O2/15% CO2/50% N2) and experimental (E: 30% CO2/70% N2). All the samples were stored at 4°C for 10 days and subjected, after 5, 8 and 10 days (t5, t8, t10), to triplicate microbiological and chemical- physical (pH, total volatile basic nitrogen, thiobarbituric acid reactive substances) analyses. At the same time, the colorimetric analysis and a sensorial evaluation were carried out (pack tightness, presence of color or odor alterations), assigning a discrete score from 0 to 5. The samples showed initial total bacterial counts close to 5 Log CFU/g: these values gradually increased during storage, exceeding the threshold of 8 Log CFU/g in the C series; lower values were detected in the E series. A similar trend was highlighted for Enterobacteriaceae, with initial loads of about 3 Log CFU/g and an increase until t10, reaching values higher than 6 Log CFU/g in the C series and close to 5 Log CFU/g in the E series (P=0.002). E. coli also showed a similar trend, although with values approximately 1 Log lower than Enterobacteriaceae. Pseudomonas spp. showed initial counts close to 4.5 Log CFU/g, with a different increase in the C series (6.5 Log CFU/g at t10) and the E series (4.95 Log CFU/g) (P= 0.006). The higher growth in the C series was also observed for lactic acid bacteria, with an increase from 3 to 5 Log CFU/g (3.8 Log CFU/g in the E series P=0.016). The other microbiological parameters showed very low counts and, in most cases undetectable counts (<2 Log CFU/g) for the entire period considered. The initial values obtained from the measurement of the colorimetric indices were within the norm for this type of product: however, starting from t5, lower values of red index and lightness in the E series were measured, with an evident greying of meat surface. The results of the sensory evaluation indicated that the product showed optimal sensorial characteristics up to 8 days of shelf-life in the C series, while the use of an oxygenfree atmosphere, despite having a moderate inhibiting effect on the microbial populations, has led to an early modification of the product (5 days of storage), due to the presence of superficial greyish areas. The microbiological characteristics of arrosticini strictly depend on the hygienic conditions of slaughtering and production; even in optimal situations, the product is particularly perishable, and requires careful management of storage temperatures and times, to maintain its quality characteristics.

Compliance between Food and Feed Safety: Eight-Year Survey (2013-2021) of Aflatoxin M1 in Raw Milk and Aflatoxin B1 in Feed in Northern Italy.

Aflatoxins (AFs) are fungal metabolites that are found in feed and food. When ruminants eat feed contaminated with aflatoxin B1 (AFB1), it is metabolised and aflatoxin M1 (AFM1) is excreted in the milk. Aflatoxins can result in hepatotoxic, carcinogenic, and immunosuppressive effects. The European Union thus set a low threshold limit (50 ng/L) for presence of AFM1 in milk. This was in view of its possible presence also in dairy products and that quantification of these toxins is mandatory for milk suppliers. In the present study, a total of 95,882 samples of whole raw milk, collected in northern Italy between 2013 and 2021, were evaluated for presence of AFM1 using an ELISA (enzyme-linked immunosorbent assay) method. The study also evaluated the relationship between feed materials collected from the same farms in the same area during the same period (2013-2021) and milk contamination. Only 667 milk samples out of 95,882 samples analysed (0.7%) showed AFM1 values higher than the EU threshold limit of 50 ng/L. A total of 390 samples (0.4%) showed values between 40 and 50 ng/L, thus requiring corrective action despite not surpassing the regulatory threshold. Combining feed contamination and milk contamination data, some feedingstuffs seem to be more effective in defying potential carryover of AFs from feed to milk. Combining the results, it can be concluded that a robust monitoring system that covers both feed, with a special focus on high risk/sentinel matrices, and milk is essential to guarantee high quality and safety standards of dairy products.

Prevalence, Virulence Potential, and Growth in Cheese of Bacillus cereus Strains Isolated from Fresh and Short-Ripened Cheeses Sold on the Italian Market.

This study investigated B. cereus presence in 122 samples belonging to 34 typologies of fresh or short-ripened cheeses made from cow, sheep, goat, or buffalo pasteurized milk, and sold on the Italian market. B. cereus was isolated at a prevalence of 9.8%, with a marked variability among cheese categories, and at low counts (always below 2.26 Log CFU/g). Twelve isolates were identified by MALDI-TOF analysis and typified by RAPD PCR as belonging to different B. cereus strains. All the strains were tested for the production of hemolysin BL, phosphatidylcholine-specific phospholipase C, proteases, and biofilm formation, and for the presence of chromosomal toxin-encoding genes (sph, plcA, cytK, entFM, bcet, nheA, nheB, nheC). Overall, 92% of strains harbored bcet, 75% the three genes nheA, nheB, and nheC, as well as plcA and sph, 67% entFM, and 33% cytK. All strains showed biofilm-forming ability. A chemical-physical characterization of the cheeses was also performed to show their suitability as substrates for B. cereus growth, showing high heterogeneity in terms of pH, aw, salt content, and concentration of organic acids. Finally, the ability to support spore germination and vegetative cell growth of a selected cheese was investigated in spores-inoculated samples maintained at 10 °C and 15 °C, showing the inhibitory effect of low storage temperatures.

Bacillus cereus in Dairy Products and Production Plants.

Spore-forming Bacillus cereus is a common contaminant of dairy products. As the microorganism is widespread in the environment, it can contaminate milk at the time of milking, but it can also reach the dairy products in each phase of production, storage and ripening. Milk pasteurization treatment is not effective in reducing contamination and can instead act as an activator of spore germination, and a potential associated risk still exists with the consumption of some processed foods. Prevalences and concentrations of B. cereus in milk and dairy products are extremely variable worldwide: in pasteurized milk, prevalences from 2% to 65.3% were reported, with concentrations of up to 3 × 105 cfu/g, whereas prevalences in cheeses ranged from 0 to 95%, with concentrations of up to 4.2 × 106 cfu/g. Bacillus cereus is also well known to produce biofilms, a serious concern for the dairy industry, with up to 90% of spores that are resistant to cleaning and are easily transferred. As the contamination of raw materials is not completely avoidable, and the application of decontamination treatments is only possible for some ingredients and is limited by both commercial and regulatory reasons, it is clear that the correct application of hygienic procedures is extremely important in order to avoid and manage the circulation of B. cereus along the dairy supply chain. Future developments in interventions must consider the synergic application of different mild technologies to prevent biofilm formation and to remove or inactivate the microorganism on the equipment.

Computational electrophysiology of the coronary sinus branches based on electro-anatomical mapping for the prediction of the latest activated region.

This work dealt with the assessment of a computational tool to estimate the electrical activation in the left ventricle focusing on the latest electrically activated segment (LEAS) in patients with left bundle branch block and possible myocardial fibrosis. We considered the Eikonal-diffusion equation and to recover the electrical activation maps in the myocardium. The model was calibrated by using activation times acquired in the coronary sinus (CS) branches or in the CS solely with an electroanatomic mapping system (EAMS) during cardiac resynchronization therapy (CRT). We applied our computational tool to ten patients founding an excellent accordance with EAMS measures; in particular, the error for LEAS location was less than 4 mm. We also calibrated our model using only information in the CS, still obtaining an excellent agreement with the measured LEAS. The proposed tool was able to accurately reproduce the electrical activation maps and in particular LEAS location in the CS branches, with an almost real-time computational effort, regardless of the presence of myocardial fibrosis, even when information only at CS was used to calibrate the model. This could be useful in the clinical practice since LEAS is often used as a target site for the left lead placement during CRT. Overall picture of the computational pipeline for the estimation of LEAS.

Characterization of a Bacillus cereus strain associated with a large feed-related outbreak of severe infection in pigs.

AIMS: Bacillus cereus is often responsible for foodborne diseases and both local and systemic infections in humans. Cases of infection in other mammals are rather rare. In this study, we report a B. cereus feed-related outbreak that caused the death of 6234 pigs in Italy. METHODS AND RESULTS: Massive doses of a Gram-positive, spore-forming bacterium were recovered from the animal feed, faeces of survived pigs and intestinal content of dead ones. The B. cereus MM1 strain was identified by MALDI-TOF MS and typified by RAPD-PCR. The isolate was tested for the production of PC-PLC, proteases, hemolysins and biofilm, for motility, as well as for the presence of genes encoding tissue-degrading enzymes and toxins. Antimicrobial resistance and pathogenicity in Galleria mellonella larvae were also investigated. Our results show that the isolated B. cereus strain is swimming-proficient, produces PC-PLC, proteases, hemolysins, biofilm and carries many virulence genes. The strain shows high pathogenicity in G. mellonella larvae. CONCLUSIONS: The isolated B. cereus strain demonstrates an aggressive profile of pathogenicity and virulence, being able to produce a wide range of determinants potentially hazardous to pigs' health. SIGNIFICANCE AND IMPACT OF STUDY: This study highlights the proficiency of B. cereus to behave as a devastating pathogen in swine if ingested at high doses and underlines that more stringent quality controls are needed for livestock feeds and supplements.

Evaluation of beef in purified sea water: microbiological and chemical-physical aspects.

In this study the influence of the maintenance of beef (Bavarian heifer meat submitted to dry aging for 1 month) in purified sea water was evaluated considering microbiological and physical-chemical parameters. The treated samples were perforated on their upper and lower surfaces, subsequently placed in sterile plastic containers, and covered with purified sea water while the control samples were wrapped in a plastic film; all the samples were stored at 2°C and sample analyses were performed on the day of receipt (t0) and after five (t5), seven (t7) and ten (t10) days of storage. The initial bacterial population was close to 6 log CFU/g, as expected in meat subjected to a long ageing. After 5 and 10 days of storage the treated samples showed significantly lower counts for most parameters (Total Bacterial Count, Enterobacteriaceae, Lactic Acid Bacteria and Pseudomonas spp.) if compared to the control samples. Halotolerant bacteria, yeasts and moulds showed no differences between the two series. During the test, the exposed surface of treated meat samples underwent a partial protein denaturation. Analyses show a moderate acidification of the meat during the first part of storage (from t0 to t5), followed by a substantial stabilization in the second part of the trial. The meat maintained in purified sea water acquired a significantly and constantly higher water retention due to the absorption of salt by the meat. No significant difference was detected in terms of tenderness between the two series.

Collection and analysis of post mortem inspection outcomes (liver lesions) from different cattle slaughtering plants located in Northern and Southern Italy.

The study evaluated the outcomes of cattle liver postmortem examination (64,766 animals) obtained from three slaughterhouses (two located in Lombardy, Northern Italy, and one in Puglia, Southern Italy) through the period 2016-2020. The frequency of specific lesions determining liver condemnation was calculated and the influence of several factors (animal age/category, geographical area, season, plant) was considered. A mean prevalence of 8% was observed, with a significant difference among the plants (range 6.4-12.8%). A significant difference was observed among the animal categories and age classes, with higher condemnation rates in animals aged more than 30 months (mainly cows). Steatosis was the most frequent lesion observed in cows (about half of the total), whereas liver abscesses were the most diffused in younger animals (half of the total in young bulls). Other frequently observed lesions were distomatosis and perihepatitis. A different pattern was observed between the two geographical areas, with a higher prevalence of steatosis in Lombardy (mainly intensive dairy farming), and of distomatosis in Puglia (animals mainly grazed on pasture). The season influenced the prevalence of lesions, and especially of steatosis (higher in summer). A different lesion prevalence was also observed between the two plants on similar animal populations, suggesting a difference in the notification and classification procedure among the plants. This study highlights the importance of a proper sharing procedure of the information obtained from the post mortem inspection in order to facilitate an optimal use of Food Chain Information and a useful feedback for farmers.

Growth potential of Listeria monocytogenes in veal tartare.

In the present study the growth potential of Listeria monocytogenes in veal tartare was evaluated. A challenge test was performed on three tartare batches at 8°C, aiming to evaluate the growth potential of the pathogen. The data indicated the absence of a significant growth (δ<0.5 log cfu/g) during the entire period. When considering intermediate sampling times, an increase of 0.56 log cfu/g was detected after five days of storage in one of the batches. Microflora of veal tartare was dominated by lactic acid bacteria, that increased gradually during the trial, reaching counts up to 7 Log CFU/g in two of the three batches considered. Spoilage bacteria were present (especially Pseudomonas spp., yeasts and Enterobacteriaceae) but in very low counts and with a limited increase during the period considered. Finally, daily maximum tolerable L. monocytogenes counts were calculated to highlight the maximum acceptable load to avoid the overcoming of the legal limit of 100 CFU/g: a total increase of 0.95 log cfu/g in 12 days of shelf-life was estimated, obtaining a "safety initial concentration" at t0 of 10 CFU/g of the pathogen.

Pseudomonas spp.: Are Food Grade Organic Acids Efficient against These Spoilage Microorganisms in Fresh Cheeses?

Psychrotolerant Pseudomonas spp. are among the most common spoilage agents in fresh, soft and semi-soft cheeses; therefore, hurdles inhibiting their growth are in strong demand by producers. This study aimed to establish Minimal Inhibiting Concentrations (MICs) of lactic and acetic acid towards P. fluorescens and to evaluate the efficacy of a cheese surface treatment with these two organic acids. MICs were determined in Brain Heart Infusion broth at 30 °C: the inhibition was achieved at a concentration of 49.96 mM and 44.40 mM of acetic and lactic acid, respectively. Two series of inhibition tests were performed on fresh "Primo sale" cheese, inoculated with P. brenneri MGM3, then dipped into different acid solutions (acetic acid: 49.96, 99.92 and 149.88 mM; lactic acid: 44.40, 88.80 and 133.20 mM) and stored at 6 °C. P. brenneri MGM3 were enumerated, including a control series. A significantly lower growth was revealed at the highest concentrations tested, both for acetic (p < 0.01) and lactic acid (p < 0.05) if compared to control samples. A conditioning of "Primo sale" surface with organic acid solutions could be a useful hurdle for Pseudomonas inhibition and shelf-life extension; it should be applied in combination with other mild interventions to fight spoilage and maintain the original product characteristics.

Evolution of Food Safety Features and Volatile Profile in White Sturgeon Caviar Treated with Different Formulations of Salt and Preservatives during a Long-Term Storage Time.

Caviar is a semi-preserved fish preparation in which cold storage (around 0 °C) and packaging under anaerobic conditions are fundamental to guarantee adequate safety parameters. Consumers seem to prefer caviar prepared with food salt only, but according to the needs of the different distribution channels, some preservatives are used in order to prolong its shelf life and to allow less restrictive storage conditions. Traditionally, the most common preservative was sodium tetraborate (borax), a salt that contributes to the sensory profile of caviar. However, due to its toxicity, borax has been banned in many countries, and the current trend is to reduce or eliminate its use. In this study, we evaluated the evolution of food safety parameters (pH, water activity, microbiological parameters) and the volatile profile during 14 months of storage in caviar samples treated with three different preservatives: I. exclusively NaCl, II. a mixture of borax and NaCl, and III. a mixture of organic acids and salts. Microbial presence was studied by means of plate counts; volatile organic compounds were identified on the sample headspace by means of solid phase microextraction with gas-chromatography and mass spectrometry. Results showed relevant differences among the three treatments investigated, with salt samples characterized by the highest viable counts and the greatest presence of volatile products driven by oxidative and spoilage processes, mainly occurring toward lipid and amino acids. On the contrary, the mixture of organic acids and salts showed the best response during the entire storage period. Finally, the employment of a multiparametric statistic model allowed the identification of different clusters based on the time of ripening and the preservative treatments used.

Evaluation of effect of chilling steps during slaughtering on the Campylobacter sp. counts on broiler carcasses.

Campylobacter spp. play an increasing role as foodborne pathogens, with poultry representing the main vehicle of infection, and control measures at the slaughterhouse have been implemented in the last years. In this study, 2 trials were performed, evaluating the effect of the chilling phases currently applied in an industrial slaughterhouse on the Campylobacter sp. contamination of broiler carcasses. In the first trial, neck skin samples were taken from 13 flocks before and after the on-chain air chilling and submitted to analysis of Campylobacter sp. count; in the second trial, 63 carcasses or cuts stored in the chilling room for variable times, with or without skin, were submitted to analysis of Campylobacter sp. count. A selection of 75 isolates was identified by PCR. All carcass skin samples taken from the first trial showed Campylobacter sp. counts higher than 0.7 log cfu/g. A wide variability in the counts (about 3 logs) was detected, showing a high correlation between the counts obtained before and after chilling. A slight decrease (P = 0.011) was observed after chilling (mean difference of about 0.3 log cfu/g), also if variability was observed among the flocks; the number of samples with high Campylobacter sp. counts (≥3 log cfu/g) was reduced (P = 0.010). In the second trial, low counts were generally detected (almost all lower than 3 log cfu/g). An evident decreasing trend was observed during storage, but the survival rate of Campylobacter on the cuts with skin was higher. All the isolates were identified as Campylobacter jejuni (72%) or Campylobacter coli. The data obtained were compared with the threshold limit set by EC Regulation 2073/2005, evidencing the impact of the sampling point on the counts. Our results highlighted the importance of applying a hurdle strategy including on-chain chilling and strict respect of the cold chain, allowing the food business operator to fulfill the process hygiene criteria and avoiding the delivery of highly contaminated meats.

Occurrence of Listeria spp. and Listeria monocytogenes Isolated from PDO Taleggio Production Plants.

The present study evaluated the presence of Listeria spp. and L. monocytogenes in four plants producing PDO Taleggio cheese. A total of 360 environmental samples were collected from different areas during production. The sampling points were identified as Food Contact Surfaces (FCS), transfer-Non Food Contact Surfaces (tr-NFCS), and non-transfer-NFCS (non-tr-NFCS). Fifty-nine ingredients/products were also analyzed. Listeria spp. was found in all the plants with a mean prevalence of 23.1%; plants that included a ripening area showed significantly higher prevalence if compared to the other plants. The positivity rate detected on FCS was moderate (~12%), but significantly lower if compared to NFCS (about 1/4 of the samples, p < 0.01). Among the FCS, higher prevalence was revealed on ripening equipment. Listeria spp. was never detected in the ingredients or products. A total of 125 Listeria spp. isolates were identified, mostly as L. innocua (almost 80%). L. monocytogenes was detected only from two FCS samples, in an area dedicated to the cutting of ripened blue cheeses; strain characterization by whole genome sequencing (WGS) evidenced a low virulence of the isolates. The results of the present study stress the importance of Listeria spp. management in the dairy plants producing PDO Taleggio and similar cheeses, mainly by the application of strict hygienic practices.

Integration of activation maps of epicardial veins in computational cardiac electrophysiology.

In this work we address the issue of validating the monodomain equation used in combination with the Bueno-Orovio ionic model for the prediction of the activation times in cardiac electro-physiology of the left ventricle. To this aim, we consider four patients who suffered from Left Bundle Branch Block (LBBB). We use activation maps performed at the septum as input data for the model and maps at the epicardial veins for the validation. In particular, a first set (half) of the latter are used to estimate the conductivities of the patient and a second set (the remaining half) to compute the errors of the numerical simulations. We find an excellent agreement between measures and numerical results. Our validated computational tool could be used to accurately predict activation times at the epicardial veins with a short mapping, i.e. by using only a part (the most proximal) of the standard acquisition points, thus reducing the invasive procedure and exposure to radiation.

Identification and Pathogenic Potential of Bacillus cereus Strains Isolated from a Dairy Processing Plant Producing PDO Taleggio Cheese.

Low levels of contamination by Bacillus cereus at the cheese farm is essential for reducing any opportunity for growth prior consumption. In this study, B. cereus distribution in a plant producing Protected Designation of Origin Taleggio cheese was investigated and the virulence potential of the isolates was evaluated. Seventy-four samples were collected from Food and Non Food Contact Surfaces (FCS, NFCS), saline curd, and Taleggio. The eleven isolates were identified, typified, and clustered. Strains were tested for the production of hemolysins, hemolysin BL (HBL), phosphatidylcholine-specific phospholipase C (PC-PLC), proteases, and biofilm, and for the presence of chromosomal toxin-encoding genes (sph, plcA, cytK, entFM, bcet, entS, nheA, nheB, nheC). B. cereus was detected on NFCS, FCS, and curd, but not in Taleggio. The isolates were grouped into six clusters, and all produced PC-PLC, hemolysins, and proteases, and most of them HBL (66.7%). All the clusters harbored the nheA, sph, plcA, entFM, and cytK genes, and some also nheB (83.3%), nheC (66.7%), bcet (50.0%), and entS (66.7%). All strains showed biofilm-forming ability. Our data reveal possible contamination of production plants and cheese curd by potentially virulent B. cereus, but bacterial absence in Taleggio highlights the efficacy of a proper management of the production phases in assuring consumer's protection.

Comparison of Chemical Composition and Safety Issues in Fish Roe Products: Application of Chemometrics to Chemical Data.

Processed fish roes are acquiring considerable importance in the modern food market, entering more and more often as an ingredient in food preparation and as caviar substitutes. In this study, we defined quality, traceability and safety issues related to processed fish roe products from different species. The results obtained allowed to distinguish eggs originated from different fish species and to discriminate between fish roes and caviar samples obtained from four different sturgeons species. We observed that roes showed a trend of grouping according to ecological and reproductive habits of fish species. We highlighted the differences between eggs originated by farmed and freshwater fish, enriched in n6 polyunsaturated fatty acids (PUFAs), and all the others, in which n3 PUFAs were prevalent. In addition, we evaluated processed fish roes under a food safety point of view, combining microbiological analysis with the determination of organic acids, used in some products as authorized preservatives. Microbiological characterization has proved a general good hygienic level for these products. Organic acids determination showed values in compliance with European Union (EU) regulations in almost of samples; in some cases, we found a mismatch between the organic acids detected and what was reported in labels. Processed fish roes could be considered a safe product that can provide to human nutrition a valuable content of essential fatty acids.

Computational Analysis of Turbulent Hemodynamics in Radiocephalic Arteriovenous Fistulas to Determine the Best Anastomotic Angles.

BACKGROUND: Hemodynamics has been known to play a major role in the development of intimal hyperplasia leading to arteriovenous fistula failure. The goal of our study is to investigate the influence of different angles of side-to-end radiocephalic anastomosis on the hemodynamic parameters that promote intimal dysfunction and therefore intimal hyperplasia. METHODS: Realistic three-dimensional meshes were reconstructed using ultrasound measurements from distal side-to-end radiocephalic fistulas. The velocity at the proximal and distal radial inflows and at specific locations along the anastomosis and cephalic vein was measured through duplex ultrasound performed by a single examiner. A computational parametric study, virtually changing the inner angle of anastomosis, was performed. For this purpose, we used advanced computational models that include suitable tools to capture the pulsatile and turbulent nature of the blood flow found in arteriovenous fistulas. The results were analyzed in terms of velocity fields, wall shear stress distribution, and oscillatory shear index. RESULTS: Results show that the regions with high oscillatory shear index, which are more prone to the development of hyperplasia, are greater and progressively shift toward the anastomosis area and the proximal vein segment with the decrease of the inner angle of anastomosis. These results are specific to distal radiocephalic fistulas because they are subject to proximal and distal radial inflow. CONCLUSIONS: The results of this study show that inner anastomosis angles approaching 60-70° seem to yield the best hemodynamic conditions for maturation and long-term patency of distal radiocephalic fistulas. Inner angles greater than 90°, representing the smooth loop technique, did not show a clear hemodynamic advantage.