The role of selenium and iodine in controlling some egg minerals

Il ruolo del selenio e dello iodio nel controllo di alcuni minerali nell’uovo. Una prova è stata condotta su sette gruppi di galline ovaiole, alimentate con un mangime di controllo (C) o contenente: olio di lino (L), olio di pesce (F), olio ricco di DHA derivante dalla micro-alga Schizochytrium sp in presenza o meno (A) di 5ppm di ioduro di potassio (AI) o di selenito di sodio (ASe) oppure di entrambi i sali (AISe). I contenuti di selenio e di zinco e di altri minerali sono stati valutati nei tuorli delle uova. A fine prova la concentrazione di selenio era aumentata in modo significativo (P<0,001), mentre quella dello zinco si era ridotta (P<0,05) nei tuorli dei gruppi ASe e AISe. I valori di Ca, Mn, Fe, Cu, Cd e Pb non differirono tra i tuorli dei vari gruppi, a parte il cadmio, la cui concentrazione si era ridotta nel gruppo AISe, attestando una influenza di iodio e selenio sulla deposizione di questo metallo

Diverse reductive dehalogenases are associated with Clostridiales-enriched microcosms dechlorinating 1,2-dichloroethane

The achievement of successful biostimulation of active microbiomes for the cleanup of a polluted site is strictly dependent on the knowledge of the key microorganisms equipped with the relevant catabolic genes responsible for the degradation process. In this work, we present the characterization of the bacterial community developed in anaerobic microcosms after biostimulation with the electron donor lactate of groundwater polluted with 1,2-dichloroethane (1,2-DCA). Through a multilevel analysis, we have assessed (i) the structural analysis of the bacterial community; (ii) the identification of putative dehalorespiring bacteria; (iii) the characterization of functional genes encoding for putative 1,2-DCA reductive dehalogenases (RDs). Following the biostimulation treatment, the structure of the bacterial community underwent a notable change of the main phylotypes, with the enrichment of representatives of the order Clostridiales. Through PCR targeting conserved regions within known RD genes, four novel variants of RDs previously associated with the reductive dechlorination of 1,2-DCA were identified in the metagenome of the Clostridiales-dominated bacterial community

The biological and structural characterization of Mycobacterium tuberculosis UvrA provides novel insights into its mechanism of action

Mycobacterium tuberculosis is an extremely well adapted intracellular human pathogen that is exposed to multiple DNA damaging chemical assaults originating from the host defence mechanisms. As a consequence, this bacterium is thought to possess highly efficient DNA repair machineries, the nucleotide excision repair (NER) system amongst these. Although NER is of central importance to DNA repair in M. tuberculosis, our understanding of the processes in this species is limited. The conserved UvrABC endonuclease represents the multi-enzymatic core in bacterial NER, where the UvrA ATPase provides the DNA lesion-sensing function. The herein reported genetic analysis demonstrates that M. tuberculosis UvrA is important for the repair of nitrosative and oxidative DNA damage. Moreover, our biochemical and structural characterization of recombinant M. tuberculosis UvrA contributes new insights into its mechanism of action. In particular, the structural investigation reveals an unprecedented conformation of the UvrB-binding domain that we propose to be of functional relevance. Taken together, our data suggest UvrA as a potential target for the development of novel anti-tubercular agents and provide a biochemical framework for the identification of small-molecule inhibitors interfering with the NER activity in M. tuberculosi

Complete genome sequence of a serotype 11A, ST62 Streptococcus pneumoniae invasive isolate

<p>Abstract</p> <p>Background</p> <p><it>Streptococcus pneumoniae </it>is an important human pathogen representing a major cause of morbidity and mortality worldwide. We sequenced the genome of a serotype 11A, ST62 <it>S. pneumoniae </it>invasive isolate (AP200), that was erythromycin-resistant due to the presence of the <it>erm</it>(TR) determinant, and carried out analysis of the genome organization and comparison with other pneumococcal genomes.</p> <p>Results</p> <p>The genome sequence of <it>S. pneumoniae </it>AP200 is 2,130,580 base pair in length. The genome carries 2216 coding sequences (CDS), 56 tRNA, and 12 rRNA genes. Of the CDSs, 72.9% have a predicted biological known function. AP200 contains the pilus islet 2 and, although its phenotype corresponds to serotype 11A, it contains an 11D capsular locus. Chromosomal rearrangements resulting from a large inversion across the replication axis, and horizontal gene transfer events were observed. The chromosomal inversion is likely implicated in the rebalance of the chromosomal architecture affected by the insertions of two large exogenous elements, the <it>erm</it>(TR)-carrying Tn<it>1806 </it>and a functional prophage designated ϕSpn_200. Tn<it>1806 </it>is 52,457 bp in size and comprises 49 ORFs. Comparative analysis of Tn<it>1806 </it>revealed the presence of a similar genetic element or part of it in related species such as <it>Streptococcus pyogenes </it>and also in the anaerobic species <it>Finegoldia magna, Anaerococcus prevotii </it>and <it>Clostridium difficile</it>. The genome of ϕSpn_200 is 35,989 bp in size and is organized in 47 ORFs grouped into five functional modules. Prophages similar to ϕSpn_200 were found in pneumococci and in other streptococcal species, showing a high degree of exchange of functional modules. ϕSpn_200 viral particles have morphologic characteristics typical of the <it>Siphoviridae </it>family and are capable of infecting a pneumococcal recipient strain.</p> <p>Conclusions</p> <p>The sequence of <it>S. pneumoniae </it>AP200 chromosome revealed a dynamic genome, characterized by chromosomal rearrangements and horizontal gene transfers. The overall diversity of AP200 is driven mainly by the presence of the exogenous elements Tn<it>1806 </it>and ϕSpn_200 that show large gene exchanges with other genetic elements of different bacterial species. These genetic elements likely provide AP200 with additional genes, such as those conferring antibiotic-resistance, promoting its adaptation to the environment.</p

Evaluation of the Active Melioidosis Detect™ test as a point-of-care tool for the early diagnosis of melioidosis: a comparison with culture in Laos.

BACKGROUND: Melioidosis is difficult to diagnose clinically and culture of Burkholderia pseudomallei is the current, imperfect gold standard. However, a reliable point-of-care test (POCT) could enable earlier treatment and improve outcomes. METHODS: We evaluated the sensitivity and specificity of the Active Melioidosis Detect™ (AMD) rapid test as a POCT and determined how much it reduced the time to diagnosis compared with culture. RESULTS: We tested 106 whole blood, plasma and buffy coat samples, 96 urine, 28 sputum and 20 pus samples from 112 patients, of whom 26 (23.2%) were culture-positive for B. pseudomallei. AMD sensitivity and specificity were 65.4 and 87.2%, respectively, the latter related to 10 weak positive reactions on urine samples, considered likely false positives. The positive predictive value was 60.7%, negative predictive value was 89.3% and concordance rate between operators reading the test was 95.7%; time to diagnosis decreased by a median of 23 h. CONCLUSIONS: Our findings confirm that a strongly positive AMD result can reduce the time to diagnosis of melioidosis. However, the AMD currently has a disappointing overall sensitivity, especially with blood fractions, and specificity problems when testing urine samples

SARS-CoV-2 infection risk is higher in vaccinated patients with inflammatory autoimmune diseases or liver transplantation treated with mycophenolate due to an impaired antiviral immune response: results of the extended follow up of the RIVALSA prospective cohort

BackgroundA relevant proportion of immunocompromised patients did not reach a detectable seroconversion after a full primary vaccination cycle against SARS-CoV-2. The effect of different immunosuppressants and the potential risks for SARS-CoV-2 infection in these subjects is largely unknown.MethodsPatients from the Rivalsa prospective, observational cohort study with planned anti SARS-CoV-2 third dose mRNA vaccination between October and December 2021 were asked to participate to this follow-up study. Patients were asked about eventual confirmed positivity to SARS-CoV-2 infection within 6 months from the third dose and to undergo a blood draw to evaluate seroconversion status after the additional vaccine shot.Results19 out of 114 patients taking part in the survey developed a confirmed SARS-CoV-2 infection; we identified mycophenolate treatment as an independent predictor of an increased risk of infection even after the third vaccine dose (OR: 5.20, 95% CI: 1.70-20.00, p=0.0053). This result is in agreement with the in vitro evidence that MMF impairs both B and T lymphocytes driven immune responses (reduction both in memory B cells producing anti-spike antibodies and in proliferating CD4+ and CD8+ T cells).ConclusionsImmunocompromised patients need an additional vaccine administration to reach a detectable seroconversion, thus fostering a more personalized approach to their clinical management. Moreover, patients undergoing mycophenolate treatment show a specific increased infection risk, with respect to other immunosuppressants thus supporting a closer monitoring of their health status

Dependence of immunoglobulin class switch recombination in B Cells on vesicular release of ATP and CD73 ectonucleotidase activity

Immunoglobulin (Ig) isotype diversification by class switch recombination (CSR) is an essential process for mounting a protective humoral immune response. Ig CSR deficiencies in humans can result from an intrinsic B cell defect; however, most of these deficiencies are still molecularly undefined and diagnosed as common variable immunodeficiency (CVID). Here, we show that extracellular adenosine critically contributes to CSR in human naive and IgM memory B cells. In these cells, coordinate stimulation of B cell receptor and toll-like receptors results in the release of ATP stored in Ca2+-sensitive secretory vesicles. Plasma membrane ectonucleoside triphosphate diphosphohydrolase 1 CD39 and ecto-5′-nucleotidase CD73 hydrolyze ATP to adenosine, which induces CSR in B cells in an autonomous fashion. Notably, CVID patients with impaired class-switched antibody responses are selectively deficient in CD73 expression in B cells, suggesting that CD73-dependent adenosine generation contributes to the pathogenesis of this disease

Fatality rate and predictors of mortality in an Italian cohort of hospitalized COVID-19 patients

Clinical features and natural history of coronavirus disease 2019 (COVID-19) differ widely among different countries and during different phases of the pandemia. Here, we aimed to evaluate the case fatality rate (CFR) and to identify predictors of mortality in a cohort of COVID-19 patients admitted to three hospitals of Northern Italy between March 1 and April 28, 2020. All these patients had a confirmed diagnosis of SARS-CoV-2 infection by molecular methods. During the study period 504/1697 patients died; thus, overall CFR was 29.7%. We looked for predictors of mortality in a subgroup of 486 patients (239 males, 59%; median age 71 years) for whom sufficient clinical data were available at data cut-off. Among the demographic and clinical variables considered, age, a diagnosis of cancer, obesity and current smoking independently predicted mortality. When laboratory data were added to the model in a further subgroup of patients, age, the diagnosis of cancer, and the baseline PaO2/FiO2 ratio were identified as independent predictors of mortality. In conclusion, the CFR of hospitalized patients in Northern Italy during the ascending phase of the COVID-19 pandemic approached 30%. The identification of mortality predictors might contribute to better stratification of individual patient risk