SARS-CoV-2 and microbiota

This letter exposes some of the many reasons why microbiota modulation in patients with COVID-19 disease and more in general, in all people at greatest risk of contracting SARS-CoV2 virus infections, should be taken into consideration

Efficacy of acoustic waves in preventing Streptococcus mutans adhesion on dental unit water line

Background: nei riuniti odontoiatrici, la qualità dell'acqua utilizzata per la refrigerazione e il risciacquo di manipoli, siringhe e altri componenti è un aspetto di notevole importanza sanitaria. L'acqua attraversa questi dispositivi mediante un circuito interconnesso di tubi di piccole dimensioni (circa 2 mm di diametro), denominato “dental unit water line” (DUWL). I DUWL possono essere fortemente colonizzati da varie specie batteriche sia in fase planctonica, che adesi o organizzati in biofilm, rappresentando una potenziale causa di infezione, non solo per i professionisti che usano abitualmente questi dispositivi, ma anche per pazienti occasionali, in particolare per i pazienti immunocompromessi. La contaminazione dei DUWL può essere prevenuta o ridotta con l'uso dei disinfettanti, ma l'eradicazione dei microrganismi adesi alle superfici interne dei DUWL o organizzati in forma di biofilm, è una sfida assai più complessa e spesso i normali metodi di disinfezione non sono pienamente efficaci. Inoltre, in ambito odontoiatrico, i disinfettanti utilizzati abitualmente per disinfettare i DUWL possono alterare la capacità adesiva del materiale utilizzato nella pratica restaurativa. Obiettivi: individuare una strategia innovativa, in grado di contrastare l'adesione batterica alle superfici dei DUWL mediante un approccio di tipo fisico, che sia più efficace nel superare il problema della contaminazione dei DUWL e ridurre il rischio di infezione rispetto ai normali metodi già in uso. A tal fine, fra le molte specie batteriche potenzialmente riscontrabili nei circuiti idrici odontoiatrici, si è deciso di avviare questo studio pilota utilizzando la specie batterica patogena S. mutans, per il suo indubbio interesse in ambito odontoiatrico e per la sua spiccata capacità di aderire e persistere su superfici inerti. Metodi: utilizzo di onde acustiche elastiche ad alta energia nel contrastare l'adesione di Streptococcus mutans alle pareti interne di un circuito idrico sperimentale riproducente un DUWL. Per evidenziare l’efficacia delle onde acustiche anche in condizioni estreme, è stata utilizzata un’elevata carica contaminante di S. mutans. Risultati: Si osserva una significativa riduzione dei batteri adesi soggetti a trattamento con onde acustiche rispetto al controllo (P = 0,003)

Insight into the possible use of the predator Bdellovibrio bacteriovorus as a probiotic

The gut microbiota is a complex microbial ecosystem that coexists with the human organism in the intestinal tract. The members of this ecosystem live together in a balance between them and the host, contributing to its healthy state. Stress, aging, and antibiotic therapies are the principal factors aecting the gut microbiota composition, breaking the mutualistic relationship among microbes and resulting in the overgrowth of potential pathogens. This condition, called dysbiosis, has been linked to several chronic pathologies. In this review, we propose the use of the predator Bdellovibrio bacteriovorus as a possible probiotic to prevent or counteract dysbiotic outcomes and look at the findings of previous research

Gut microbiota related to Giardia duodenalis, Entamoeba spp. and Blastocystis hominis infections in humans from Côte d'Ivoire.

INTRODUCTION: Literature data provide little information about protozoa infections and gut microbiota compositional shifts in humans. This preliminary study aimed to describe the fecal bacterial community composition of people from Côte d'Ivoire harboring Giardia duodenalis, Entamoeba spp., and Blastocystis hominis, in trying to discover possible alterations in their fecal microbiota structure related to the presence of such parasites. METHODOLOGY: Twenty fecal samples were collected from people inhabiting three different localities of Côte d'Ivoire for copromicroscopic analysis and molecular identification of G. duodenalis, Entamoeba spp., and B. hominis. Temporal temperature gradient gel electrophoresis (TTGE) was used to obtain a fingerprint of the overall bacterial community; quantitative polymerase chain reaction (qPCR) was used to define the relative abundances of selected bacterial species/group, and multivariate statistical analyses were employed to correlate all data. RESULTS: Cluster analysis revealed a significant separation of TTGE profiles into four clusters (p < 0.0001), with a marked difference for G. duodenalis-positive samples in relation to the others (p = 5.4×10-6). Interestingly, qPCR data showed how G. duodenalis-positive samples were related to a dysbiotic condition that favors potentially harmful species (such as Escherichia coli), while Entamoeba spp./B. hominis-positive subjects were linked to a eubiotic condition, as shown by a significantly higher Faecalibacterium prausnitzii-Escherichia coli ratio. CONCLUSIONS: This preliminary investigation demonstrates a differential fecal microbiota structure in subjects infected with G. duodenalis or Entamoeba spp./B. hominis, paving the way for using further next-generation DNA technologies to better understand host-parasite-bacteria interactions, aimed at identifying potential indicators of microbiota changes

Eubiosis and dysbiosis: the two sides of the microbiota

The microbial ecosystem of the gastrointestinal tract is characterized by a great number of microbial species living in balance by adopting mutualistic strategies. The eubiosis/dysbiosis condition of the gut microbiota strongly influences our healthy and disease status. This review briefly describes microbiota composition and functions, to then focus on eubiosis and dysbiosis status: the two sides of the microbiot

Violacein, an indole-derived purple-colored natural pigment produced by Janthinobacterium lividum, inhibits the growth of head and neck carcinoma cell lines both in vitro and in vivo

Violacein (VIO; 3-[1,2-dihydro-5-(5-hydroxy-1H-indol-3-yl)-2-oxo-3H-pyrrol-3-ylidene]-1,3-dihydro-2H-indol-2-one), an indole-derived purple-colored pigment, produced by a limited number of Gram-negative bacteria species, including Chromobacterium violaceum and Janthinobacterium lividum, has been demonstrated to have anti-cancer activity, as it interferes with survival transduction signaling pathways in different cancer models. Head and neck carcinoma (HNC) represents the sixth most common and one of the most fatal cancers worldwide. We determined whether VIO was able to inhibit head and neck cancer cell growth both in vitro and in vivo. We provide evidence that VIO treatment of human and mouse head and neck cancer cell lines inhibits cell growth and induces autophagy and apoptosis. In fact, VIO treatment increased PARP-1 cleavage, the Bax/Bcl-2 ratio, the inhibition of ERK1 and ERK2 phosphorylation, and the expression of light chain 3-II (LC3-II). Moreover, VIO was able to induce p53 degradation, cytoplasmic nuclear factor kappa B (NF-κB) accumulation, and reactive oxygen species (ROS) production. VIO induced a significant increase in ROS production. VIO administration was safe in BALB/c mice and reduced the growth of transplanted salivary gland cancer cells (SALTO) in vivo and prolonged median survival. Taken together, our results indicate that the treatment of head and neck cancer cells with VIO can be useful in inhibiting in vivo and in vitro cancer cell growth. VIO may represent a suitable tool for the local treatment of HNC in combination with standard therapies

Quantitative Evaluation of Bacteria Adherent and in Biofilm on Single-Wall Carbon Nanotube-Coated Surfaces

Biofilm is a common bacterial lifestyle, and it plays a crucial role in human health, causing biofilm-mediated infections. Recently, to counteract biofilm development, new nano-structured biomaterials have been proposed. However, data about the antibacterial properties of nano-structured surfaces are fragmentary and controversial, and, in particular, the susceptibility of nano-structured materials to colonization and biofilm formation by bacterial pathogens has not been yet thoroughly considered. Here, the ability of the pathogenic Streptococcus mutans and Pseudomonas aeruginosa to adhere and form biofilm on surfaces coated with single-wall carbon nanotubes (SWCNTs) was analyzed. Our results showed that the surfaces of SWCNTs-coated glass beads (SWCNTs-GBs) were colonized at the same extent of uncoated GBs both by S. mutans and P. aeruginosa. In conclusion, our results demonstrate that single wall SWCNTs-coated surfaces are not suitable to counteract bacterial adhesion and biofilm development

Effect of urban wastewater discharge on the abundance of antibiotic resistance genes and antibiotic-resistant Escherichia coli in two Italian rivers

Background: Wastewater treatment plants (WWTPs) are microbial factories aimed to reduce the amount of nutrients and pathogenic microorganisms in the treated wastewater before its discharge into the environment. We studied the impact of urban WWTP effluents on the abundance of antibiotic resistance genes (ARGs) and antibiotic-resistant Escherichia coli (AR-E. coli) in the last stretch of two rivers (Arrone and Tiber) in Central Italy that differ in size and flow volume. Methods: Water samples were collected in three seasons upstream and downstream of the WWTP, at the WWTP outlet, and at sea sites near the river mouth, and analyzed for the abundance of ARGs by qPCR and AR-E. coli using cultivation followed by disk diffusion assays. Results: For all studied genes (16S rRNA, intI1, sul1, ermB, blaTEM, tetW and qnrS), absolute concentrations were significantly higher in the Tiber than in the Arrone at all sampling sites, despite their collection date, but the prevalence of target ARGs within bacterial communities in both rivers was similar. The absolute concentrations of most ARGs were also generally higher in the WWTP effluent with median levels between log 4 and log 6 copies per ml but did not show differences along the studied stretches of rivers. Statistically significant site effect was found for E. coli phenotypic resistance to tetracycline and ciprofloxacin in the Arrone but not in the Tiber. Conclusions: In both rivers, diffuse or point pollution sources other than the studied WWTP effluents may account for the observed resistance pattern, although the Arrone appears as more sensitive to the wastewater impact considering its lower flow volume

Mo1927 Mucosa-Associated Microbiota and Promoter Methylation Status of Genes Involved in Immune Response in Crohn's Disease Patients

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