58 research outputs found

    Laboratory automation, informatics, and artificial intelligence: current and future perspectives in clinical microbiology

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    Clinical diagnostic laboratories produce one product—information—and for this to be valuable, the information must be clinically relevant, accurate, and timely. Although diagnostic information can clearly improve patient outcomes and decrease healthcare costs, technological challenges and laboratory workflow practices affect the timeliness and clinical value of diagnostics. This article will examine how prioritizing laboratory practices in a patient-oriented approach can be used to optimize technology advances for improved patient care

    A synthetic peptide as a novel anticryptococcal agent.

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    Summary An engineered, killer decapeptide (KP) has been synthesized based on the sequence of a recombinant, single-chain anti-idiotypic antibody (KT-scFv) acting as a functional internal image of a yeast killer toxin. Killer decapeptide exerted a strong fungicidal activity against Candida albicans, which was attributed to peptide interaction with β-glucan. As this polysaccharide is also a critical component of the cryptococcal cell wall, we wondered whether KP was also active against Cryptococcus neoformans, a human pathogen of increasing medical importance. We found that KP was able to kill both capsular and acapsular C. neoformans cells in vitro. Furthermore, KP impaired the production of specific C. neoformans virulence factors including protease and urease activity and capsule formation, rendering the fungus more susceptible to natural effector cells. In vivo treatment with KP significantly reduced fungal burden in mice with cryptococcosis and, importantly, protected the majority of immunosuppressed animals from an otherwise lethal infection. Given the relevance of cryptococcosis in immunocompromised individuals and the inability of conventional drugs to completely resolve the infection, the results of the present study indicate KP as an ideal candidate for further studies on novel anticryptococcal agents

    Breastfeeding and transmission of cytomegalovirus to preterm infants. Case report and kinetic of CMV-DNA in breast milk

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    <p>Abstract</p> <p>Background</p> <p>Breastfeeding has a major impact on CMV epidemiology. Postnatal CMV reactivation's incidence during lactation is nearby the maternal seroprevalence. Although perinatal CMV infection has practically no consequences in term newborn, it may cause, in some cases, a severe symptomatic disease in preterm newborns.</p> <p>The aims of the present study are to evaluate the rate and clinical expression of CMV infection breast milk transmitted in preterm infants and to check the safety of the freezing treated breast milk.</p> <p>Methods</p> <p>The study included fifty-seven preterm infants and their CMV seropositive mothers. Fresh breast milk samples have been collected from 1<sup>st </sup>to 9<sup>th </sup>postpartum week. Both fresh breast milk and 72, 96, 120 hours frozen samples have been examined, checking the presence of CMV; urine samples have been tested too.</p> <p>Results</p> <p>70.2% of tested mothers showed reactivation of the infection, and CMV-positive breast milk during the six weeks postpartum has been found. However, only one infant was infected by CMV, developing hepatic affection concomitantly with a multi-system involvement, as shown CMV DNA detection in urine, saliva, blood, gastric aspirate, and stools.</p> <p>Conclusion</p> <p>Freezing breast milk at -20°C and pasteurization may respectively reduce or eliminate the viral load.</p

    Antibody Complementarity-Determining Regions (CDRs): A Bridge between Adaptive and Innate Immunity

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    Background: It has been documented that, independently from the specificity of the native antibody (Ab) for a given antigen (Ag), complementarity determining regions (CDR)-related peptides may display differential antimicrobial, antiviral and antitumor activities. Methodology/Principal Findings: In this study we demonstrate that a synthetic peptide with sequence identical to VHCDR3 of a mouse monoclonal Ab (mAb) specific for difucosyl human blood group A is easily taken up by macrophages with subsequent stimulation of: i) proinflammatory cytokine production; ii) PI3K-Akt pathway and iii) TLR-4 expression. Significantly, V HCDR3 exerts therapeutic effect against systemic candidiasis without possessing direct candidacidal properties. Conclusions/Significance: These results open a new scenario about the possibility that, beyond the half life of immunoglobulins, Ab fragments may effectively influence the antiinfective cellular immune response in a way reminiscen

    Role of CD45 Signaling Pathway in Galactoxylomannan-Induced T Cell Damage

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    Previously, we reported that Galactoxylomannan (GalXM) activates the extrinsic and intrinsic apoptotic pathways through an interaction with the glycoreceptors on T cells. In this study we establish the role of the glycoreceptor CD45 in GalXM-induced T cell apoptosis, using CD45+/+ and CD45−/− cell lines, derived from BW5147 murine T cell lymphoma. Our results show that whereas CD45 expression is not required for GalXM association by the cells, it is essential for apoptosis induction. In CD45+/+ cells, CD45 triggering by GalXM reduces the activation of Lck, ZAP70 and Erk1/2. Conversely, in CD45−/− cells, Lck was hyperphosphorylated and did not show any modulation after GalXM stimulation. On the whole, our findings provide evidence that the negative regulation of Lck activation occurs via CD45 engagement. This appears to be related to the capacity of GalXM to antagonize T cell activation and induce T cell death. Overall this mechanism may be responsible for the immune paralysis that follows GalXM administration and could explain the powerful immunosuppression that accompanies cryptococcosis

    Influence of indinavir on virulence and growth of Cryptococcus neoformans

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    Indinavir selectively inhibited production of some virulence factors of Cryptococcus neoformans, such as urease and protease, but not melanin and phospholipase; moreover, it interfered with capsule formation. These effects led to increased susceptibility of C. neoformans to intracellular killing by natural effector cells. Prolonged incubation with indinavir resulted in inhibition of fungal growth. Indinavir can attenuate the virulence of the fungus, thus augmenting its susceptibility to the antimicrobial activity of natural effector cells. The reduction in cryptococcal infections in human immunodeficiency virus-positive patients might also be related to the antifungal activity of highly active antiretroviral therapy

    The Glucocorticoid-Induced Tumor Necrosis Factor Receptor-Related Gene Modulates the Response to Candida albicans Infection

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    The glucocorticoid-induced tumor necrosis factor (TNF) receptor-related gene (GITR; TNFRSF18) modulates immune response activating coaccessory signals in T cells and is expressed at high levels in CD4(+)CD25(+) cells. Its ligand (GITRL) is expressed in antigen-presenting cells, where it is capable of promoting signaling. We investigated the role of GITR/GITRL interaction during disseminated candidiasis in GITR knockout (GITR(−/−)) mice. GITR(−/−) mice survived longer and had a significantly decreased yeast load in kidneys and brain compared to GITR(+/+) mice. Since protective immunity to the fungus is mediated by antigen-specific T helper (Th) 1 cells, we studied in vitro cytokine production following infection. CD4(+) T cells of GITR(−/−) mice demonstrated a more efficient Th1 polarization as suggested by a two- to threefold decreased production of interleukin- (IL-)4 and IL-10 and a four- to fivefold increased production of gamma interferon compared to GITR(+/+) mice. This effect was not due to differences in lymphocyte and dendritic cell (DC) subpopulations in infected mice as demonstrated by flow cytometric studies. To verify whether DC activity was differently modulated, DCs were cocultured with CD4(+) T cells in the presence of heat-inactivated Candida albicans. DCs, cocultured with GITR(+/+) CD4(+)CD25(+) cells produced a lower amount of IL-12 than DCs cocultured with GITR(−/−) CD4(+)CD25(+) T cells. These results suggest that GITR regulates susceptibility to systemic candidiasis by negatively modulating IL-12 production and promoting polarization of CD4(+) T cells towards Th2 by analogy with OX40, another TNF receptor superfamily member
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