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

Animal rennets as sources of dairy lactic acid bacteria

The microbial composition of artisan and industrial animal rennet pastes was studied by using both culture-dependent and -independent approaches. Pyrosequencing targeting the 16S rRNA gene allowed to identify 361 operational taxonomic units (OTUs) to the genus/species level. Among lactic acid bacteria (LAB), Streptococcus thermophilus and some lactobacilli, mainly Lactobacillus crispatus and Lactobacillus reuteri, were the most abundant species, with differences among the samples. Twelve groups of microorganisms were targeted by viable plate counts revealing a dominance of mesophilic cocci. All rennets were able to acidify ultrahigh-temperature-processed (UHT) milk as shown by pH and total titratable acidity (TTA). Presumptive LAB isolated at the highest dilutions of acidified milks were phenotypically characterized, grouped, differentiated at the strain level by randomly amplified polymorphic DNA (RAPD)-PCR analysis, and subjected to 16S rRNA gene sequencing. Only 18 strains were clearly identified at the species level, as Enterococcus casseliflavus, Enterococcus faecium, Enterococcus faecalis, Enterococcus lactis, Lactobacillus delbrueckii, and Streptococcus thermophilus, while the other strains, all belonging to the genus Enterococcus, could not be allotted into any previously described species. The phylogenetic analysis showed that these strains might represent different unknown species. All strains were evaluated for their dairy technological performances. All isolates produced diacetyl, and 10 of them produced a rapid pH drop in milk, but only 3 isolates were also autolytic. This work showed that animal rennet pastes can be sources of LAB, mainly enterococci, that might contribute to the microbial diversity associated with dairy productions

Genotoxicity and epigenotoxicity of carbazole-derived molecules on mcf-7 breast cancer cells

The carbazole compounds PK9320 (1-(9-ethyl-7-(furan-2-yl)-9H-carbazol-3-yl)-N-methylmethanamine) and PK9323 (1-(9-ethyl-7-(thiazol-4-yl)-9H-carbazol-3-yl)-N-methylmethanamine), second-generation analogues of PK083 (1-(9-ethyl-9H-carbazol-3-yl)-N-methylmethanamine), restore p53 signaling in Y220C p53-mutated cancer cells by binding to a mutation-induced surface crevice and acting as molecular chaperones. In the present paper, these three molecules have been tested for mutant p53-independent genotoxic and epigenomic effects on wild-type p53 MCF-7 breast adenocarcinoma cells, employing a combination of Western blot for phospho-γH2AX histone, Comet assay and methylation-sensitive arbitrarily primed PCR to analyze their intrinsic DNA damageinducing and DNA methylation-changing abilities. We demonstrate that small modifications in the substitution patterns of carbazoles can have profound effects on their intrinsic genotoxic and epigenetic properties, with PK9320 and PK9323 being eligible candidates as “anticancer compounds” and “anticancer epi-compounds” and PK083 a “damage-corrective” compound on human breast adenocarcinoma cells. Such different properties may be exploited for their use as anticancer agents and chemical probes

Melatonin Inhibits Inflammatory Response of Intestinal Epithelial Cells

Melatonin, oral-used in sleep disorders treatment, is the main secretory product of the pineal gland and in gastrointestinal tract (GIT) in which it has a local physiological poorly characterized role. Intraperitoneally-administered high dose has anti-inflammatory effects in experimental model of Inflammatory Bowel Diseases but the mechanisms is unclarified. Literature data show that melatonin inhibits the activation of neutrophils and monocytes and it is therefore conceivable that it has also inhibitory effect on mucosal inflammatory cell activation. The aim of this study was to evaluate in an in vitro model of inflamed intestinal epithelium the potential protective effects of melatonin. Differentiated monolayers of intestinal epithelial Caco-2 cells, in which the inflammatory response was induced by interleukin-1β and interferon-γ, were exposed at concentrations of melatonin in the range from 1 nM to 50 M. We also exposed differentiated monolayers to melatonin in presence of luzindole, an antagonist of melatonin membrane receptors, to determine whether or not potential effect of melatonin involve membrane receptors. Our results clearly show for the first time that melatonin decreased in release and expression some inflammatory mediators, including nitric oxide, interleukin-6, interleukin-8, cyclooxygenase-2, and that the treatment is associated with a reduced activation of the nuclear factor-B. Moreover, luzindole did not reverse the melatonin inhibition of stimulated- IL-6 release, indicating that the melatonin protective effect may be membrane receptor-independent. Our findings suggest that assumption of pharmaceutical preparation of melatonin can also exert beneficial effects to gastrointestinal physiology

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

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