42 research outputs found
A preliminary study on a novel bioaugmentation technique enhancing lactic acid production by mixed cultures fermentation
The paper is a preliminary study on the selection of lactic acid producing microorganisms from a mixed microbial
population via bioaugmentation. The bioaugmentation technique is based on pH sudden variations occurring in
sequential batch steps of a dark fermentation process applied to simple substrates. Different conditions are tested
and compared. The structure of microbial communities and concentrations of metabolic intermediates are
analyzed to study the possible substrate conversion routes. Obtained results indicate that the initial mixed culture
produced a lactic acid percentage of 5% in terms of CODLA/CODPRODUCTS. In the most favourable conditions, the
selected culture produced a lactic acid percentage of 59%. The analysis of the composition of microbial communities before and after the bioaugmentation processes, indicates that lactic acid production mainly results
from the population change to bacteria belonging to the genus Bacillus. Indeed, the relative abundance of Bacilli
increased from 0.67%, to 8.40% during the bioaugmentation cycle
An Ecotoxicological Evaluation of Four Fungal Metabolites with Potential Application as Biocides for the Conservation of Cultural Heritage
Biocides based on chemical synthetic compounds have been commonly used to counteract
damages caused by microorganisms on stone cultural heritage. However, in the last few years, the use
of commercial and traditional biocides has been banned and/or limited due to their dangerous profile
for the environment, as well as human and animal health. Natural products could be used as suitable
alternatives for cultural heritage purposes, as they have low toxicity and stability compared with
synthetic pesticides. Even if most of the investigated solutions have already shown promising results,
their efficiency, ecotoxicological, and chemical features are poorly investigated. In this manuscript, we aimed to evaluate the ecotoxicological profile of four fungal metabolites—namely, cavoxin, epiepoformin, seiridin, and sphaeropsidone—with potential antimicrobial properties for monumental artworks. A battery of ecotoxicological tests using Aliivibrio fischeri (bacterium), Raphidocelis subcapitata (alga), Raphanus sativus L. (macrophyte), Daphnia magna (crustacean), and Caenorhabditis elegans (nematode) revealed a relative lower toxicity of these compounds, especially when compared with Preventol® and Rocima®, commercial biocides mainly used for the conservation of cultural heritage
Comparative assessment of the quality of commercial black and green tea using microbiology analyses
Drinking tea constitutes a tradition which is deeply rooted in the culture of several countries. Moreover, in recent years, tea consumption is growing all over the world. Improper herbal tea storage (long periods, humid environments) represents a relevant health hazard for consumers because of the growth of bacteria and molds
Screening and isolation of microbes from a Mud Community of Ischia Island Thermal Springs: preliminary analysis of a bioactive compound
Introduction: Balneotherapy centers of Ischia island (Italy) offer treatments for different dermatological diseases (psoriasis, acne, atopic dermatitis) and upper respiratory tract infections. In this study, we integrated morphological and molecular approaches to give bacterial diversity of microbial mat samples collected from the thermae of Ischia.
Methods: Samples were collected during 2019 at four sites. Some bacterial strains ATCC for antibacterial and antibiofilm Activity were tested. After morphological characterization, screening for antagonistic isolates was made. The colonies isolated from thermal mud samples were submitted to molecular characterization. Susceptibility testing by dilution spotting was carried out and antibacterial efficacies of most active isolate were evaluated with a Minimal inhibition concentration assay. Biofilm formation, inhibition, eradication were examined. Statistical analyses were carried out utilizing Microsoft® Excel 2016/XLSTAT©-Pro.
Results: We isolated a natural compound with antimicrobial and antibiofilm activities.
Conclusions: The results obtained in this study are discussed in the context of how hydrothermal systems are important environmental source of uncharted antimicrobial and antibiofilm compounds. This is, to our knowledge, the first view of a spring water microbiome analysis of Ischia
Evaluation of Microbial Communities of Bottled Mineral Waters and Preliminary Traceability Analysis Using NGS Microbial Fingerprints
The microbiological monitoring of mineral bottled waters results is crucial for the prevention
of outbreaks in consumers. European and International regulations establish the quality of
water intended for human consumption in order to preserve human health from the negative effects
deriving from water contamination. Advanced methods targeting the faster detection of potential
pathogens in drinking water may consent to the creation of an early warning system, enhancing
water quality management. This study aimed to suggest the implementation of standard water
quality evaluations, based on the characterization of the microbial composition of mineral bottled
water brands, contributing to the periodic control of the water’s microbiological stability along with
the shelf life, and, consequently, the stability of the supplying sources. Bottled water microbiota
analysis was combined with the qualitative and quantitative evaluation of microbial loads in time,
and the monitoring was performed in two seasons and two different storage conditions for a total of
sixty days. The employment of molecular microbiology techniques (NGS and Sanger sequencing),
compared to standardized cultural methods and integrated with metagenomic analysis, combining
chemical and physical indicators for each sample, allowing for the generation of specific fingerprints
for mineral bottled waters, pointing at simplifying and improving the foreseen risk assessment
strategies to ensure the adequate traceability, quality and safety management of drinking water
Allium ursinum and Allium oschaninii against Klebsiella pneumoniae and Candida albicans Mono- and Polymicrobic Biofilms in In Vitro Static and Dynamic Models
The present study assesses the in vitro antibiofilm potential activity of extracts of wild
Allium ursinum and Allium oschaninii. The active ingredients of the extracts were obtained with a
technique named Naviglio (rapid solid–liquid dynamic extraction, RSLDE) which is based on an
innovative and green solid–liquid extraction methodology. The extracts were tested against models
of mono‐ and polymicrobial biofilm structures of clinically antibiotic‐resistant pathogens, Klebsiella
pneumoniae ATCC 10031 and Candida albicans ATCC 90028. Biofilms were studied using a static and
a dynamic model (microtiter plates and a CDC reactor) on three different surfaces reproducing what
happens on implantable medical devices. Antimicrobic activities were determined through
minimum inhibitory concentration (MIC), while antibiofilm activity was assessed by minimum
biofilm eradication concentration (MBEC) using a crystal violet (CV) biofilm assay and colony
forming unit (CFU) counts. Results showed that both Allium extracts eradicated biofilms of the
tested microorganisms well; biofilms on Teflon were more susceptible to extracts than those on
polypropylene and polycarbonate, suggesting that when grown on a complex substrate, biofilms
may be more tolerant to antibiotics. Our data provide significant advances on antibiotic
susceptibility testing of biofilms grown on biologically relevant materials for future in vitro and in
vivo applications
Envy, Social Comparison, and Depression on Social Networking Sites: A Systematic Review
This study aims to review the evidence for the reciprocal relationship between envy and social comparison (SC) on social networking sites (SNSs) and depression. We searched PsychINFO, PubMed, and Web of Science from January 2012 to November 2022, adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A total of 9 articles met our inclusion criteria. In all articles reviewed, a simple correlation was found between SC on SNSs, envy, and depression. Three cross-sectional studies successfully tested a model with envy as a mediator between SNSs and depression. The moderating role of additional variables such as self-efficacy, neuroticism, SC orientation, marital quality, and friendship type was also evident. The only two studies that were suitable to determine direction found that depression acted as a predictor rather than an outcome of SC and envy, and therefore depression might be a relevant risk factor for the negative emotional consequences of SNSs use
Anti-Biofilm Activity of Phenyllactic Acid against Clinical Isolates of Fluconazole-Resistant Candida albicans
: Commonly found colonizing the human microbiota, Candida albicans is a microorganism known for its ability to cause infections, mainly in the vulvovaginal region, and is responsible for 85% to 90% of vulvovaginal candidiasis (VVC) cases. The development of drug resistance in C. albicans isolates after long-term therapy with fluconazole is an important complication to solve and new therapeutic strategies are required to target this organism and its pathogenicity. In the present study, phenyllactic acid (PLA) an important broad-spectrum antimicrobial compound was investigated for its antifungal and antivirulence activities against clinical isolates of C. albicans. Previously characterized strains of C. albicans isolates from women with VVC and C. albicans ATCC90028 were used to evaluate the antimicrobial and time dependent killing assay activity of PLA showing a MIC 7.5 mg mL-1 and a complete reduction of viable Candida cells detected by killing kinetics after 4 h of treatment with PLA. Additionally, PLA significantly reduced the biomass and the metabolic activity of C. albicans biofilms and impaired biofilm formation also with changes in ERG11, ALS3, and HWP1 genes expression as detected by qPCR. PLA eradicated pre-formed biofilms as showed also with confocal laser scanning microscopy (CLSM) observations. Furthermore, the compound prolonged the survival rate of Galleria mellonella infected by C. albicans isolates. These results indicate that PLA is a promising candidate as novel and safe antifungal agents for the treatment of vulvovaginal candidiasis
"Valutazione dello stato di salute ambientale del lago Patria ed ecosistemi limitrofi"_ Dati preliminari e indicazioni sui primi interventi attuabili
A new schedule of fotemustine in temozolomide-pretreated patients with relapsing glioblastoma
In the present study we investigated the feasibility and effectiveness of a new biweekly schedule of fotemustine (FTM) in patients with recurrent glioblastoma, after at least one previous treatment. The primary endpoint was progression-free survival at 6 months; secondary objectives were clinical response, overall survival, disease-free survival, and toxicity. Forty patients (median age 52.8 years; median Karnofsky Performance Status at progression 90) underwent second-line chemotherapy with FTM. Selected patients were previously treated with a standard radiotherapy course with concomitant temozolomide (TMZ). After tumor relapse or progression proven by magnetic resonance imaging (MRI), all patients underwent chemotherapy with FTM, given intravenously at dose of 80 mg/m2 every 2 weeks for five consecutive administrations (induction phase), and then every 3 weeks at 100 mg/m2 as maintenance. A total of 329 infusions were administered; the median number of cycles administered was 8. All patients completed the induction phase, and 29 patients received at least one maintenance infusion. Response to treatment was assessed using MacDonald criteria. One complete response [2.5%, 95% confidence interval (CI): 0–10%], 9 partial responses (22.5%, 95% CI: 15–37%), and 16 stable diseases (40%, 95% CI: 32–51%) were observed. Median time to progression was 6.7 months (95% CI: 3.9–9.1 months). Progression-free survival at 6 months was 61%. Median survival from beginning of FTM chemotherapy was 11.1 months. The schedule was generally well tolerated; the main toxicities were hematologic (grade 3 thrombocytopenia in two cases). To the best of our knowledge, this is the first report specifically dealing with the use of a biweekly induction schedule of FTM. The study demonstrates that FTM has therapeutic efficacy as single-drug second-line chemotherapy with a favorable safety profile