No description available.

Biofilm formation on medical devices is responsible for a substantial portion of healthcare associated infections with approximately 99,000 deaths and estimated financial burden of $28-$45 billion annually. Given the long-standing challenges of biofilm eradication, physical and chemical surface modifications to prevent biofilm formation from the early adhesion stage, continue to gain momentum. Nanoscale structural features, ubiquitous in both natural and synthetic surfaces, are increasingly recognized to have wide-ranging effects on microorganism adhesion and biofilm development. In this thesis, bio-inspired nanofiber-coated polystyrene surfaces were developed to systematically investigate how highly ordered surface nanostructures (200nm-2000nm in size) impact adhesion and proliferation of model fungal pathogen, Candida albicans. A theoretical model for cell-textured surface interaction was also developed using thermodynamic principles to demonstrate that single cell adhesion to surface can be used to describe the population behavior. The trend for adhesion density of C. albicans on nanofiber-textured surfaces of varying diameters correlates with our theoretical finding of adherent single-cell energetic state. Findings from this thesis can be used for enhanced ab initio design of antifouling surfaces for medical applications and beyond. We demonstrate a successful prototypical example of reduction in biofilm formation by optimally designed nanofiber coating of urinary catheters. / Master of Science

Fungal infection and mycotoxin contamination in agricultural products are a serious food safety issue. The detection of fungal infection and mycotoxin contamination in food products should be in a rapid way. A Near-infrared (NIR) hyperspectral imaging system was used to detect fungal infection in 2013 crop year canola, wheat, and barley at different periods after inoculation and different concentration levels of ochratoxin A in wheat and barley. Artificially fungal infected (Fungi: Aspergillus glaucus, Penicillium spp.) kernels of canola, wheat and barley, were subjected to single kernel imaging after 2, 4, 6, 8, and 10 weeks post inoculation in the NIR region from 1000 to 1600 nm at 61 evenly distributed wavelengths at 10 nm intervals. The acquired image data were in the three-dimensional hypercube forms, and these were transformed into two-dimensional data. The two-dimensional data were subjected to principal component analysis to identify significant wavelengths based on the highest principal component factor loadings. Wavelengths 1100, 1130, 1250, and 1300 nm were identified as significant for detection of fungal infection in canola kernels, wavelengths 1280, 1300, and 1350 nm were identified as significant for detection of fungal infection in wheat kernels, and wavelengths 1260, 1310, and 1360 nm were identified as significant for detection of fungal infection in barley kernels. The linear, quadratic and Mahalanobis statistical discriminant classifiers differentiated healthy canola kernels with > 95% and fungal infected canola kernels with > 90% classification accuracy. All the three classifiers discriminated healthy wheat and barley kernels with > 90% and fungal infected wheat and barley kernels with > 80% classification accuracy. The wavelengths 1300, 1350, and 1480 nm were identified as significant for detection of ochratoxin A contaminated wheat kernels, and wavelengths 1310, 1360, 1480 nm were identified as significant for detection of ochratoxin A contaminated barley kernels. All the three statistical classifiers differentiated healthy wheat and barley kernels and ochratoxin A contaminated wheat and barley kernels with a classification accuracy of 100%. The classifiers were able to discriminate between different durations of fungal infections in canola, wheat, and barley kernels with classification accuracy of more than 80% at initial periods (2 weeks) of fungal infection and 100% at the later periods of fungal infection. Different concentration levels of ochratoxin A contamination in wheat and barley kernels were discriminated with a classification accuracy of > 98% at ochratoxin A concentration level of ≤ 72 ppb in wheat kernels and ≤ 140 ppb in barley kernels and with 100% classification accuracy at higher concentration levels. / May 2016

No description available.

Objective: To review the place in therapy of isavuconazole, the active metabolite of isavuconazonium sulfate, via a review of the available literature on drug chemistry, spectrum of activity, pharmacokinetic/pharmacodynamic profile and trials assessing clinical efficacy and safety. Methods: Relevant data, original research articles and reviews, were gathered primarily through the use of a PubMed database search. The search was conducted without date restrictions in order to collect both historical and recent data regarding isavuconazole. Key findings: Isavuconazole is a triazole currently approved not only for use in invasive aspergillosis and mucormycosis but also has demonstrable activity against Candida species and other common fungal pathogens. This drug has features which make it more clinically appealing compared to other azoles with similar indications. In specific, isavuconazole does not require a cyclodextrin vehicle due to its water solubility, and at present, does not require therapeutic drug monitoring. Moreover, isavuconazole has displayed improved safety and tolerability compared to voriconazole. Available data from Phase III clinical trials shows isavuconazole to be a possible therapeutic option to currently available therapies for which it is approved; however, clinical conclusions should be reserved until results have been published and more data from clinical use is reported. Conclusions: Isavuconazole is a new triazole with broad‐spectrum antifungal activity including invasive aspergillosis and mucormycosis.

The interleukin (IL)-12 family of cytokines plays a key role in the orchestration of cellular immune responses, bridging innate and adaptive immunity. The founding member, IL-12, was discovered in the late 1980s as the first heterodimeric cytokine, composed of a 40 kDa (p40) and 35 kDa (p35) subunit. Years of basic and clinical research on this prototypical T helper type (Th)1 cytokine revealed its importance in immunity to intracellular non-viral infections, as well as in cancer and autoimmune diseases. Since the discovery of IL-23 as another cytokine composed of the p40 subunit of IL-12 in the year 2000, IL-23, rather than IL-12, could be shown to be the key player in rodent models of autoimmune diseases such as multiple sclerosis and rheumatoid arthritis. With accumulating evidence revealing IL-23 as the crucial regulator of a non-classical pathway of cellular immunity which is hallmarked by IL-17 producing T cells it is intriguing to gain understanding of the importance of such findings in immunity to infections. The present work describes a series of in vivo studies investigating the role of endogenous as well as exogenous IL-23 in a murine model of chronic fungal infection, cryptococcosis. To address the role of endogenous IL-23, wild-type (WT), IL-12- (IL-12p35-/-), IL-23- (IL-23p19-/-) deficient, as well as IL-12- and IL-23- double deficient (p40-deficient) mice on a C57BL/6 background were infected with Cryptococcus neoformans (C. neoformans). Following infection, p40-deficient mice demonstrated higher mortality than IL-12p35-/- mice. Reconstitution of p40-deficient mice with recombinant murine IL-23 prolonged their survival to levels similar to IL-12p35-/- mice. IL-23p19-/- mice showed a moderately reduced survival time and delayed fungal clearance in the liver. While interferon (IFN)-γ production was similar in WT and IL-23p19-/- mice, production of IL-17 was strongly impaired in the latter. IL-23p19-/- mice produced fewer hepatic granulomata relative to organ burden and showed defective recruitment of mononuclear cells to the brain. Moreover, activation of microglia cells and expression of IL-1β, IL-6, and MCP-1 in the brain was impaired. SUMMARY - 80 - The second part of the present work explores the mechanisms underlying the IL-23 effects by characterizing the role of exogenous IL-23. C. neoformans-infected C57BL/6 WT mice treated with recombinant murine IL-23 showed significantly prolonged survival time as compared to mock-treated control mice. However, complete survival throughout the observation period (100 days) was only achieved following IL-12 treatment. At day 21 post infection (p.i.) the IL-23-treated mice as well as the IL-12 group had a significantly lower fungal burden in the brain than the control mice. However, while IL-12 treatment was associated with elevated serum levels of the proinflammatory mediators IFN-γ, tumor necrosis factor (TNF)-α and nitric oxide, IL-23-treated animals, although more resistant, developed a Th2 response similar to the control group as measured by serum IgE levels. Further experiments to assess the mechanism of action were based on the finding of reduced fungal burden at the site of infection, the peritoneal cavity, at day 8 p.i. following IL-23 treatment. This microbicidal effect was also seen in p40-deficient as well as in T and B cell deficient (RAG-deficient) mice. Administration of IL-23 led to enhanced recruitment of inflammatory cells, not only of T cells but also cells of the innate immune system such as DCs, natural killer cells and granulocytes to the infected site. Although numbers of macrophages were not altered following IL-23 treatment, co-stimulatory molecules were markedly up-regulated on such cells. The chemokine/cytokine pattern induced by IL-23 treatment was hallmarked by proinflammatory mediators such as MCP-1, IL-1β, IL-6, TNF-α and IL-17, but also the Th2 associated cytokine IL-5. From these results it can be concluded that a non-classical immune pathway induced by IL-23 complements the more dominant role of IL-12 in protection against C. neoformans. This novel immune response is characterized by an enhancement of the inflammatory cell response and the production of a proinflammatory cytokine pattern hallmarked by IL-1β, IL-6, TNF-α and IL-17.

Pneumocystis species are opportunistic fungal pathogens that cause severe pneumonia in immunocompromised hosts, including AIDS patients. Pneumocystis species have a biphasic life cycle consisting of single-nucleated trophic forms and ascus-like cysts. Both stages live within the host, and, thus, must contend with threats from the host immune system. The cyst cell wall β-glucans have been shown to stimulate immune responses in lung epithelial cells, dendritic cells and alveolar macrophages. Little is known about how the trophic life forms, which do not have a fungal cell wall, interact with immune cells. In this study, the immune response to the life cycle stages of Pneumocystis murina was evaluated. Here, we report differences in the immune response of immunocompetent mice to the trophic and cystic life cycle stages of P. murina. Upon infection with purified trophic forms, wild-type adult mice developed a delayed innate and adaptive immune response compared to inoculation with the normal mixture of trophic forms and cysts. Cysts, but not trophic forms, stimulated Th1-type responses in the lungs of infected mice. Surprisingly, trophic forms are sufficient to generate protective adaptive responses, leading to clearance in immunocompetent mice. We report that CD4+ T cells primed in the presence of trophic forms are sufficient to mediate clearance of trophic forms and cysts. In addition, primary infection with trophic forms is sufficient to prime B cell memory responses capable of clearing a secondary infection with Pneumocystis following CD4+ T cell depletion. While trophic forms are sufficient for initiation of adaptive immune responses in immunocompetent mice, infection of immunocompromised RAG2-/- mice with trophic forms in the absence of cysts does not lead to the severe weight loss and infiltration of innate immune cells associated with the development of Pneumocystis pneumonia. Dendritic cells screen the alveolar spaces for pathogens, and are in a prime position to initiate the immune response against lung pathogens, including Pneumocystis. Our data demonstrate that trophic forms broadly dampen the ability of dendritic cells to respond to pathogen-associated molecular patterns. Bone marrow-derived dendritic cells were stimulated with trophic forms, a mixture of trophic forms and cysts, and various other inflammatory materials, including β-glucan. Trophic forms inhibited multiple components involved in antigen presentation by dendritic cells, including secretion of inflammatory cytokines and expression of MHC class II and costimulatory molecules on the cell surface. Furthermore, trophic forms suppressed or failed to induce the expression of multiple genes related to activation and maturation in dendritic cells. Dendritic cells silenced by trophic forms are unable to induce CD4+ T cell responses. These data suggest that immune evasion by trophic forms is dependent on the suppression of innate responses, and the development of adaptive immunity represents a “point of no return” at which the trophic forms are no longer able to escape clearance.

Les infections fongiques sont une complication fréquente des patients d’hématologie et en particulier des patients ayant reçu un greffe de cellules souches hématopoïétiques (CSH). L’objectif de ce travail était d’identifier les facteurs de risque d’infections fongiques intrinsèques et la transmission.Nous avons d’abord étudié l’aspergillose invasive (AI) qui est l’infection fongique la plus fréquente chez les greffés de CSH en croisant les données du registre européen des greffés ProMise et la base de données de l’étude prospective SAIF. Nous avons mené une étude cas-témoins nichée dans une cohorte de 185 cas et 651 témoins appariés. Les facteurs associés à la survenue d’une aspergillose étaient l’irradiation corporelle totale, une GvH aiguë de grade ≥2 et la rechute de l’hémopathie. Trente-cinq cas étaient précoces (<J40), 33 tardifs (entre J40 et J100) et 117 très tardifs (>J100). Le facteur associé à la survenue d’une AI précoce était l’absence de prise de greffe. Le facteur associé à la survenue d’une AI tardive était la GvH aiguë de grade 3-4. Les facteurs associés à la survenue d’une AI très tardive étaient la GvH aiguë de grade ≥2, la rechute et la neutropénie secondaire. Tous les facteurs pré-greffe étaient effacés par les facteurs post-greffe.Puis nous avons étudié la transmission d’infection fongique par l’étude d’une épidémie de pneumocystose survenue dans le service. Douze cas de pneumocystose sont survenus en 7 mois dans le service soir beaucoup plus qu’au cours des années précédentes. L’analyse moléculaire a permis de montrer que 4 cas appartenaient au même génotype, qui est un génotype rare jamais décrit dans une série de plus de 300 génotypes en Europe. La carte de transmission a permis de constater que ces 4 patients se sont rencontrés uniquement en hôpital de jour. Cette étude est la première démonstration moléculaire d’une épidémie de pneumocystose dans un service d’hématologie. / Fungal infections are a common complication of hematology patients and especially in hematopoietic stem cell transplantation (HSCT) recipients. The objective of this work was to identify intrinsic risk factors for fungal infections and transmission.We first studied invasive aspergillosis (IA), which is the most common fungal infection after HSCT by crossing data from the European HSCT registry ProMise and the prospective study database SAIF. We conducted a nested case-control study in a cohort of 185 cases and 651 matched controls. Factors associated with onset of aspergillosis were total body irradiation, acute GVHD grade ≥2, and relapse of the underlying disease. Thirty-five IA were early (<D40), 33 late (between D40 and D100) and 117 very late (> D100). The factor associated with the occurrence of an early IA was the absence of engraftment. The factor associated with the occurrence of late IA was acute grade 3-4 GvH. Factors associated with the occurrence of very late IA were acute GVHD grade ≥2, relapse, and secondary neutropenia. All pre-transplant factors were supplanted by post-transplant factors.Then we studied the transmission of fungal infection by studying a pneumocystosis outbreak occurring in the hematology department. Twelve cases occurred within 7 months. Molecular analysis showed that 4 of them belonged to the same genotype, which is a rare genotype never described in a series of more than 300 genotypes in Europe. The transmission map permitted to identify that these 4 patients met only in the daycare center. This study is the first molecular demonstration of a pneumocystis outbreak in a hematology ward.

Invasive aspergillosis (IA) is a major opportunistic fungal infection in patients with haematological malignancies. Morbidity and mortality rates are high despite anti-fungal treatment, as the compromised status of immune system prevents the host from responding optimally to conventional therapy. This raises the consideration for immunotherapy as an adjunctive treatment. In this study, we evaluated the utility of expanded human NK cells as treatment against Aspergillus fumigatus infection in vitro and in vivo. The NK cells were expanded and activated by K562 cells genetically modified to express 4-1BB ligand and membrane-bound interleukin-15 (K562-41BBL-mbIL-15) as feeders. The efficacy of these cells was investigated in A. fumigatus killing assays in vitro and as adoptive cellular therapy in vivo. The expanded NK cells possessed potent killing activity at low effector-to-target ratio of 2:1. Fungicidal activity was morphotypal-dependent and most efficacious against A. fumigatus conidia. Fungicidal activity was mediated by dectin-1 receptors on the expanded NK cells leading to augmented release of perforin, resulting in enhanced direct cytolysis. In an immunocompromised mice pulmonary aspergillosis model, we showed that NK cell treatment significantly reduced fungal burden, hence demonstrating the translational potential of expanded NK cells as adjunctive therapy against IA in immunocompromised patients.

No description available.