Microbiological investigation of Raphanus sativus L. grown hydroponically in nutrient solutions contaminated with spoilage and pathogenic bacteria

The survival of eight undesired (spoilage/pathogenic) food related bacteria (Citrobacter freundii PSS60, Enterobacter spp. PSS11, Escherichia coli PSS2, Klebsiella oxytoca PSS82, Serratia grimesii PSS72, Pseudomonas putida PSS21, Stenotrophomonas maltophilia PSS52 and Listeria monocytogenes ATCC 19114T) was investigated in mineral nutrient solution (MNS) during the crop cycle of radishes (Raphanus sativus L.) cultivated in hydroponics in a greenhouse. MNSs were microbiologically analyzed weekly by plate count. The evolution of the pure cultures was also evaluated in sterile MNS in test tubes. The inoculated trials contained an initial total mesophilic count (TMC) ranging between 6.69 and 7.78 Log CFU/mL, while non-sterile and sterile control trials showed levels of 4.39 and 0.97 Log CFU/mL, respectively. In general, all inoculated trials showed similar levels of TMC in MNS during the experimentation, even though the levels of the inoculated bacteria decreased. The presence of the inoculums was ascertained by randomly amplified polymorphic DNA (RAPD) analysis applied on the isolates collected at 7-day intervals. At harvest, MNSs were also analyzed by denaturing gradient gel electrophoresis (DGGE). The last analysis, except P. putida PSS21 in the corresponding trial, did not detect the other bacteria, but confirmed that pseudomonads were present in un-inoculated MNSs. Despite the high counts detected (6.44 and 7.24 CFU/g), only C. freundii PSS60, Enterobacter spp. PSS11 and K. oxytoca PSS82 were detected in radishes in a living form, suggesting their internalization

Risk of Seven-Day Worsening and Death: A New Clinically Derived COVID-19 Score

This monocentric, retrospective, two-stage observational study aimed to recognize the risk factors for a poor outcome in patients hospitalized with SARS-CoV-2 infection, and to develop and validate a risk score that identifies subjects at risk of worsening, death, or both. The data of patients with SARS-CoV-2 infection during the first wave of the pandemic were collected and analyzed as a derivation cohort. Variables with predictive properties were used to construct a prognostic score, which was tried out on a validation cohort enrolled during the second wave. The derivation cohort included 494 patients; the median age was 62 and the overall fatality rate was 22.3%. In a multivariable analysis, age, oxygen saturation, neutrophil-to-lymphocyte ratio, C-reactive protein and lactate dehydrogenase were independent predictors of death and composed the score. A cutoff value of 3 demonstrated a sensitivity (Se), specificity (Sp), positive predictive value (PPV) and negative predictive value (NPV) of 93.5%, 68.5%, 47.4% and 97.2% for death, and 84.9%, 84.5%, 79.6% and 87.9% for worsening, respectively. The validation cohort included 415 subjects. The score application showed a Se, Sp, PPV and NPV of 93.4%, 61.6%, 29.5% and 98.1% for death, and 81%, 76.3%, 72.1% and 84.1% for worsening, respectively. We propose a new clinical, easy and reliable score to predict the outcome in hospitalized SARS-CoV-2 patients

In vivo application and dynamics of lactic acid bacteria for the four-season production of Vastedda-like cheese.

Twelve lactic acid bacteria (LAB), previously selected in vitro (Gaglio et al., 2014), were evaluated in situ for their potential to act as starter cultures for the continuous four-season production of Vastedda-like cheese, madewith raw ewes' milk. The strains belonged to Lactobacillus delbrueckii, Lactococcus lactis subsp. cremoris, Leuconostoc mesenteroides subsp. mesenteroides and Streptococcus thermophilus. LABwere first inoculated in multiple-strain combinations on the basis of their optimal growth temperatures in three process conditions which differed for milk treatment and medium for strain development: process 1, growth of strains in the optimal synthetic media and pasteurised milk; process 2, growth of strains in whey based medium (WBM) and pasteurised milk; and process 3, growth of strains in WBM and raw milk. The strains that acidified the curds in short time, as shown by a pH drop, were all mesophilic and were then tested in a single inoculum through process 3. Randomly amplified polymorphic DNA (RAPD)-PCR analysis applied to the colonies isolated from the highest dilutions of samples confirmed the dominance of the added strains after curd acidification, stretching and storage. After 15 days of refrigerated storage, the decrease in pH values showed an activity of the mesophilic strains at low temperatures, but only Lc. lactis subsp. cremoris PON153, Ln. mesenteroides subsp. mesenteroides PON259 and PON559 increased their number during the 15 days at 7 \ub0C. A sensory evaluation indicated that the cheeses obtained by applying protocol 3 and by inoculation with lactococci are the most similar to the protected denomination of origin (PDO) cheese and received the best scores by the judges. Thus, the experimental cheeses obtained with raw milk and inoculated with single and multiple combinations of lactococci were subjected to the analysis of the volatile organic compounds (VOCs) carried out by a headspace solid phase microextraction (SPME) technique coupled with gas chromatography with mass spectrometric detection (GC/MS). The dominance of lactococci over thermophilic LAB of raw milk was verified during summer production and, based on the combination of VOC profiles and sensory evaluation of the final cheeses, the multi-strain Lactococcus culture resulted in the most suitable starter preparation for the full-year production of Vastedda-like cheese

Melatonin reduces inflammatory response in human intestinal epithelial cells stimulated by interleukin-1β

Melatonin is the main secretory product of the pineal gland, and it is involved in the regulation of periodic events. A melatonin production independent of the photoperiod is typical of the gut. However, the local physiological role of melatonin at the intestinal tract is poorly characterized. In this study, we evaluated the anti-inflammatory activities of melatonin in an in vitro model of inflamed intestinal epithelium. To this purpose, we assessed different parameters usually associated with intestinal inflammation using IL-1 beta-stimulated Caco-2 cells. Differentiated monolayers of Caco-2 cells were preincubated with melatonin (1 nmol/L-50 mu mol/L) and then exposed to IL-1 beta. After each treatment, different inflammatory mediators, DNA-breakage, and global DNA methylation status were assayed. To evaluate the involvement of melatonin membrane receptors, we also exposed differentiated monolayers to melatonin in the presence of luzindole, a MT1 and MT2 antagonist. Our results showed that melatonin, at concentrations similar to those obtained in the lumen gut after ingestion of dietary supplements for the treatment of sleep disorders, was able to attenuate the inflammatory response induced by IL-1 beta. Anti-inflammatory effects were expressed as both a decrease of the levels of inflammatory mediators, including IL-6, IL-8, COX-2, and NO, and a reduced increase in paracellular permeability. Moreover, the protection was associated with a reduced NF-kappa B activation and a prevention of DNA demethylation. Conversely, luzindole did not reverse the melatonin inhibition of stimulated-IL-6 release. In conclusion, our findings suggest that melatonin, through a local action, can modulate inflammatory processes at the intestinal level, offering new opportunities for a multimodal management of IBD

La macerazione post-fermentativa prolungata come strategia innovativa per il miglioramento dei vini rossi

Lo scopo del presente studio \ue8 stato quello di valutare l\u2019influenza della macerazione post-fermentativa, estesa a 90 giorni, sulla composizione microbica e chimica del vino rosso \u201cAglianico di Taurasi\u201d. Le analisi microbiologiche hanno messo in evidenza la presenza di popolazioni di lieviti e batteri lattici, vitali e metabolicamente attivi, durante l\u2019intero periodo di macerazione post-fermentativa. Durante il processo di macerazione, la specie principalmente riscontrata era rappresentata da Saccharomyces cerevisiae, mentre al 60\ub0 giorno, \ue8 stata rilevata una concentrazione simile di Debaromyces carsonii e Zygosaccharomyces bisporus. Tuttavia, \ue8 stata osservata una bassa diversit\ue0 di specie, spiegabile sulla base delle condizioni stressanti (elevata concentrazione di etanolo, basso pH e mancanza di nutrienti) che caratterizzano il processo e determinano una forte pressione selettiva. Tali condizioni di stress non hanno influenzato negativamente la diversit\ue0 dei lieviti a livello di ceppo per la comunit\ue0 di S. cerevisiae. Infatti, escludendo il ceppo starter, otto diversi ceppi indigeni sono stati rilevati ad alti livelli durante la macerazione. I nostri risultati hanno confermato osservazioni precedenti che individuano l\u2019ambiente della cantina come fonte di ceppi autoctoni che, una volta adattatisi al processo di vinificazione, potrebbero anche dominare in condizioni stressanti, quali quelle caratteristiche di una macerazione prolungata. Inoltre, sono stati valutati gli effetti delle attivit\ue0 di lieviti e dei batteri lattici sulla composizione del vino durante la macerazione post-fermentativa fino a 90 giorni. Lo studio ha permesso di ottenere delle informazioni sull\u2019ecologia microbica del vino e ha dimostrato che sia i lieviti che i batteri lattici sono in grado di esercitare attivit\ue0 metaboliche, anche durante la macerazione post-fermentativa estesa a 90 giorni. I dati ottenuti dalle analisi chimiche e sensoriali indicano che la macerazione, nell\u2019intervallo tra 40 e 50 giorni, migliora significativamente la qualit\ue0 del prodotto finale, a causa dell\u2019aumento di rotondit\ue0 sensoriale, complessit\ue0 e attivit\ue0 antiossidante di vino. Il presente studio ha determinato un avanzamento delle nostre conoscenze sul contenuto di polifenoli e sulla composizione dei vini quando viene condotta una macerazione prolungata, superiore, cio\ue8, alla durata comunemente indicata dalla pratica enologica per la produzione di vino Aglianico. Ulteriori ricerche sull\u2019identificazione e distribuzione delle specie di batteri lattici potrebbero essere utili al fine di comprendere in maniera esaustiva l\u2019effetto della macerazione sull\u2019ecologia microbica di vino. Infatti, sperimentazioni condotte con variet\ue0 di uve diverse e in differenti cantine potrebbero essere utili per ampliare le nostre conoscenze sul processo di macerazione del vino

La macerazione post-fermentativa prolungata come strategia innovativa per il miglioramento dei vini rossi

Lo scopo del presente studio \ue8 stato quello di valutare l\u2019influenza della macerazione post-fermentativa, estesa a 90 giorni, sulla composizione microbica e chimica del vino rosso \u201cAglianico di Taurasi\u201d. Le analisi microbiologiche hanno messo in evidenza la presenza di popolazioni di lieviti e batteri lattici, vitali e metabolicamente attivi, durante l\u2019intero periodo di macerazione post-fermentativa. Durante il processo di macerazione, la specie principalmente riscontrata era rappresentata da Saccharomyces cerevisiae, mentre al 60\ub0 giorno, \ue8 stata rilevata una concentrazione simile di Debaromyces carsonii e Zygosaccharomyces bisporus. Tuttavia, \ue8 stata osservata una bassa diversit\ue0 di specie, spiegabile sulla base delle condizioni stressanti (elevata concentrazione di etanolo, basso pH e mancanza di nutrienti) che caratterizzano il processo e determinano una forte pressione selettiva. Tali condizioni di stress non hanno influenzato negativamente la diversit\ue0 dei lieviti a livello di ceppo per la comunit\ue0 di S. cerevisiae. Infatti, escludendo il ceppo starter, otto diversi ceppi indigeni sono stati rilevati ad alti livelli durante la macerazione. I nostri risultati hanno confermato osservazioni precedenti che individuano l\u2019ambiente della cantina come fonte di ceppi autoctoni che, una volta adattatisi al processo di vinificazione, potrebbero anche dominare in condizioni stressanti, quali quelle caratteristiche di una macerazione prolungata. Inoltre, sono stati valutati gli effetti delle attivit\ue0 di lieviti e dei batteri lattici sulla composizione del vino durante la macerazione post-fermentativa fino a 90 giorni. Lo studio ha permesso di ottenere delle informazioni sull\u2019ecologia microbica del vino e ha dimostrato che sia i lieviti che i batteri lattici sono in grado di esercitare attivit\ue0 metaboliche, anche durante la macerazione post-fermentativa estesa a 90 giorni. I dati ottenuti dalle analisi chimiche e sensoriali indicano che la macerazione, nell\u2019intervallo tra 40 e 50 giorni, migliora significativamente la qualit\ue0 del prodotto finale, a causa dell\u2019aumento di rotondit\ue0 sensoriale, complessit\ue0 e attivit\ue0 antiossidante di vino. Il presente studio ha determinato un avanzamento delle nostre conoscenze sul contenuto di polifenoli e sulla composizione dei vini quando viene condotta una macerazione prolungata, superiore, cio\ue8, alla durata comunemente indicata dalla pratica enologica per la produzione di vino Aglianico. Ulteriori ricerche sull\u2019identificazione e distribuzione delle specie di batteri lattici potrebbero essere utili al fine di comprendere in maniera esaustiva l\u2019effetto della macerazione sull\u2019ecologia microbica di vino. Infatti, sperimentazioni condotte con variet\ue0 di uve diverse e in differenti cantine potrebbero essere utili per ampliare le nostre conoscenze sul processo di macerazione del vino

Optimization of environmental conditions for kefiran production by kefir grain as scaffold for tissue engineering

The aim of this work was to investigate the fermentation medium and environmental requirements for the production of exopolysaccharide (EPS) Kefiran from natural culture (Kefir grains). We have found that the fermentation medium and temperature are critical for Kefiran production during the 24 h cultivation of kefir grains. The Kefiran obtained from fat cow milk was used to evaluate its potential application as scaffold for tissue engineering. Kefiran scaffold were obtained via solvent casting and direct quenching. Thermal and morphology features were evaluated by DSC and SEM, respectively

Microbiological Characteristics of Wild Edible Mushrooms and Effect of Temperature during Storage of Morchella conica

Background: The continuous worldwide increase of consumption of fresh mushrooms has registered in the recent years. The major goal of this study was to determine the microbiological characteristics of wild edible mushrooms and effect of temperature during storage of Morchella conica. Methods: Wild mushrooms of the species Boletus edulis, Cantharellus cibarius, and Leccinum aurantiacum were collected in a mixed forest of Picea abies, Betula pendula, and Pinus sylvestris located in Tartu territory, Estonia. Faecal indicators, potential pathogens, spoilage bacteria, and microfungi (yeasts and moulds) were evaluated. M. conica was microbiologically investigated for 24 days under different thermal regimes, including 4, 8, 12, 15, 20, and 28 °C. The statistical analysis was conducted with SAS 9.2 software. Results: The microbial counts of wild mushrooms, ranging from 6.81 to 7.68 log10 CFU/g for total mesophilic count, were generally higher (p<0.05) than those registered for marketed samples ranging from 4.60 to 7.39 log10 CFU/g. The dynamics of total mesophilic microorganisms on M. conica stored at different temperatures indicated that stationary and death phases occurred earlier with increasing temperature and that the highest levels were registered at 28 °C at the 2nd day of storage. Conclusion: This work highlights consistent differences in terms of microbiological properties among different mushrooms species. The results clearly showed that total mesophilic populations developed at high levels quickly at temperatures more than 15 °C, but also the refrigeration did not stop the microbiological decay of mushrooms. DOI: 10.18502/jfqhc.6.1.45

Microbiological characteristics of wild edible mushrooms and effect of temperature during storage of Morchella conica

Background: The continuous worldwide increase of consumption of fresh mushrooms has registered in the recent years. The major goal of this study was to determine the microbiological characteristics of wild edible mushrooms and effect of temperature during storage of Morchella conica. Methods: Wild mushrooms of the species Boletus edulis, Cantharellus cibarius, and Leccinum aurantiacum were collected in a mixed forest of Picea abies, Betula pendula, and Pinus sylvestris located in Tartu territory, Estonia. Faecal indicators, potential pathogens, spoilage bacteria, and microfungi (yeasts and moulds) were evaluated. M. conica was microbiologically investigated for 24 days under different thermal regimes, including 4, 8, 12, 15, 20, and 28 °C. The statistical analysis was conducted with SAS 9.2 software. Results: The microbial counts of wild mushrooms, ranging from 6.81 to 7.68 log10 CFU/g for total mesophilic count, were generally higher (p&lt;0.05) than those registered for marketed samples ranging from 4.60 to 7.39 log10 CFU/g. The dynamics of total mesophilic microorganisms on M. conica stored at different temperatures indicated that stationary and death phases occurred earlier with increasing temperature and that the highest levels were registered at 28 °C at the 2nd day of storage. Conclusion: This work highlights consistent differences in terms of microbiological properties among different mushrooms species. The results clearly showed that total mesophilic populations developed at high levels quickly at temperatures more than 15 °C, but also the refrigeration did not stop the microbiological decay of mushrooms

Activation of wooden vats with selected lactic acid bacteria for the year-round production of traditional Vastedda-like cheese

Vastedda is a pasta filata cheese made from raw ewes\u2019 milk without the addition of starter cultures. Cheese production is carried out in wooden vats characterized by microbial biofilms hosting lactic acid bacteria (LAB) responsible for the acidification of the curds. Vastedda cheese was traditionally produced during the summer season, but it is currently produced throughout the year. In order to minimize production variability, several LAB were isolated from Vastedda PDO cheeses, characterized for their technological potential (Gaglio et al., 2014a) and selected to obtain the best strain combination for the production (Gaglio et al., 2014b). In this study, the multiple strain culture composed of Lactococcus lactis subsp. cremoris PON36, PON153 and PON203 was applied during production carried out at large scale level in a dairy factory with bulk milk from different farms using new chestnut wooden vats [commercial production (CMP)]. The same trials were also carried out in controlled conditions at an experimental dairy factory using milk from only one farm [controlled production (CNP)]. In both CMP and CNP productions were used two new vats, one activated with a whey containing the lactococci selected and one traditionally activated with the whey. In the experimental trials, conducted in the vats activated with the lactococci, the same lactococci were also used as starter culture, while the control productions were performed without the addition of starter. Productions were performed every day for the first 5 d and at 5 d intervals for a month. Microbiological counts and strain recognition performed by randomly amplified polymorphic DNA (RAPD)-PCR demonstrated the ability of the triple Lactococcus combination to form a stable biofilm in the active vats. Cheeses analysed at T0 (soon after production) and after 15 days of refrigerated storage showed the persistence and dominance of the inoculated LAB