Comparison of different blood compartments for the detection of circulating DNA using a rat model of Pneumocystis pneumonia.

Pneumocystis is mostly found in the alveolar spaces, but circulation of viable organisms also occurs and suggests that the detection of DNA in blood could be used as a noninvasive procedure to improve the diagnosis of Pneumocystis pneumonia (PcP). In order to determine the optimal compartment for Pneumocystis DNA detection, we used a rat model of PcP and tested the presence of Pneumocystis with a quantitative mtLSU targeting real-time PCR in four blood compartments: whole blood, clot, serum and Platelet-Rich-Plasma (PRP). All samples from 4 Pneumocystis-free control rats were negative. Pneumocystis was detected in 79, 64, 57, and 57% of samples from 14 PcP rats, respectively, but DNA release was not related to pulmonary loads. These data confirm the potential usefulness of Pneumocystis DNA detection in the blood for PcP diagnosis and suggest that whole blood could be the most appropriate compartment for Pneumocystis detection.

Immune evasion by acquisition of complement inhibitors: the mould Aspergillus binds both factor H and C4b binding protein.

Pathogenic fungi represent a major threat particularly to immunocompromised hosts, leading to severe, and often lethal, systemic opportunistic infections. Although the impaired immune status of the host is clearly the most important factor leading to disease, virulence factors of the fungus also play a role. Factor H (FH) and its splice product FHL-1 represent the major fluid phase inhibitors of the alternative pathway of complement, whereas C4b-binding protein (C4bp) is the main fluid phase inhibitor of the classical and lectin pathways. Both proteins can bind to the surface of various human pathogens conveying resistance to complement destruction and thus contribute to their pathogenic potential. We have recently shown that Candida albicans evades complement by binding both Factor H and C4bp. Here we show that moulds such as Aspergillus spp. bind Factor H, the splicing variant FHL-1 and also C4bp. Immunofluorescence and flow cytometry studies show that the binding of Factor H and C4bp to Aspergillus spp. appears to be even stronger than to Candida spp. and that different, albeit possibly nearby, binding moieties mediate this surface attachment.

Inhibition of fibroblast growth factor receptor 1 endocytosis promotes axonal branching of adult sensory neurons.

Fibroblast growth factors (FGFs) promote axon growth during development and regeneration of the nervous system. Among the four types of FGF receptors (FGFRs), FGFR1 is expressed in adult sensory neurons of dorsal root ganglia (DRG), and overexpression of FGFR1 promotes FGF-2-induced elongative axon growth in vitro. Ligand-induced activation of FGFR1 is followed by endocytosis and lysosomal degradation, which leads to the termination of receptor signaling. We previously reported that the lysosomal inhibitor leupeptin enhances FGF-2-induced elongative axon growth of adult DRG neurons overexpressing FGFR1. To better understand the role of subcellular localization of FGFR1 in axon growth, we analyzed the effects of inhibition of endocytosis of FGFR1 on FGF-2-induced neurite outgrowth in PC12 pheochromocytoma cells and adult DRG neurons. The endocytosis inhibitors methyl-ß-cyclodextrin (MßCD) and chlorpromazine enhanced surface localization of FGFR1 in PC12 cells and DRG neurons. Furthermore, MßCD and chlorpromazine increased FGF-2-induced neurite outgrowth of PC12 cells and axonal branching of adult DRG neurons overexpressing FGFR1, whereas MßCD inhibited FGF-2-induced axonal elongation. Analysis of the signaling pathways involved in axon morphology revealed that FGF-2-induced phosphorylation of extracellular signal-regulated kinase (ERK) and Akt was increased by inhibition of FGFR1 endocytosis. Together, our results imply that inhibition of FGFR1 endocytosis by MßCD or chlorpromazine promotes FGF-2-induced axonal branching. The results of this study confirm that internalization of FGFR1 controls axon growth and morphology of adult sensory neurons via selective activation of intracellular signaling pathways.

Austrian clinical practice with anidulafungin in 2008: a multicenter survey.

Anidulafungin had demonstrated favorable efficacy versus fluconazole in a randomized trial on invasive Candida infections. Since patient characteristics in the post-approval use of antifungals likely deviate from clinical trials, we surveyed the use of anidulafungin in clinical routine. We performed a retrospective survey of the post-approval use of anidulafungin in 9 Austrian clinical centers. Anidulafungin was used in 129 critically ill patients with severe comorbidities and multiple risk factors. Indications were suspected invasive fungal infections (IFI) (61%), proven candidemia (19%), and at risk for IFI (prophylaxis, 20%). Candida colonization in conjunction with other risk factors prompted treatment in many patients. predominant pathogens were C. albicans, C. glabrata and C. krusei. Anidulafungin was mostly used for pre-emptive (69%) and first-line treatment (17%) of invasive candidiasis. Treatment response, i.e. complete response/stabilization as determined by investigators (89% in the overall population; 87% for documented candidemia) and survival rates (81% and 75%, respectively) were similar to previous trial data. No breakthrough IFI and few adverse events were reported. Overall, favorable clinical experiences were documented with anidulafungin in the clinical routine setting.

The Nationwide Austrian Aspergillus Registry: a prospective data collection on epidemiology, therapy and outcome of invasive mould infections in immunocompromised and/or immunosuppressed patients.

A prospective, observational, multicentre study was performed to assess the incidence, diagnosis, epidemiology and outcome of invasive mould infections (IMIs) reported to the Nationwide Austrian Aspergillus Registry. In total, 186 cases were recorded, corresponding to an annual incidence of 42 cases/1000 patients at risk or 2.36 cases/100000 inhabitants. Patients with acute myelogenous leukaemia (34%) and lung transplant recipients (17%) are currently at highest risk for IMI, followed by a mixed population with impaired immunity (14%). In total, 34%, 30% and 36% were proven, probable and possible cases of IMI. Predominant pathogens were Aspergillus spp. (67%), followed by the zygomycetes (28%). Voriconazole was the most frequently administered agent (38%), followed by caspofungin (20%) and posaconazole (19%). Eighty patients (43%) received antifungal prophylaxis for ≥7 days, 30% of whom (24 patients) suffered from a breakthrough infection. The overall crude 12-week mortality was 34%. Multivariate analysis showed that outcome and survival did not correlate with the status of fungal disease, breakthrough infection, fungal species or age (P>0.05). Aspergillosis remains the most commonly identified IMI amongst immunocompromised and/or immunosuppressed patients, but other moulds constitute a significant problem. Survival from IMIs appears to have improved and the main challenge is to overcome breakthrough fungal infections.

A 1-year Aspergillus terreus surveillance study at the University Hospital of Innsbruck: molecular typing of environmental and clinical isolates.

Aspergillus terreus appears to have become an increasingly frequent cause of opportunistic infections in the University Hospital of Innsbruck (UHI) and is of serious concern because of in vivo and in vitro resistance to amphotericin B. In order to determine the possible relationship between environmental contamination by A. terreus and the occurrence of invasive aspergillosis, a 1-year prospective study (2004-2005) was carried out in the UHI. Isolates obtained from air samples of various high-risk settings and those from surveillance cultures of proven and probable aspergillosis (EORTC/MSG criteria) were examined by genotyping. Within 1 year, 34 and 15 A. terreus isolates were collected from the environment and from patients, respectively. Genotypic analysis with rapid amplification of polymorphic DNA (RAPD) PCR and the combination of three different primers (R108, CII, P4) revealed 46 distinct genotypic profiles (types 1-46). No strain similarity was detected among and within the patients and environmental areas, indicating a great genomic diversity in A. terreus, which is common in the environment of Innsbruck and a source of invasive infections in immunosuppressed patients. Genotypical diversity was found in clinical and environmental A. terreus isolates.

Influence of amphotericin B and amphotericin B colloidal dispersion on the functions of human phagocytes in defence against Aspergillus species.

This study investigated the in vitro effects of amphotericin B and amphotericin B colloidal dispersion (ABCD) on phagocytosis and inhibition of germination of clinical isolates of Aspergillus spp. by monocyte-derived macrophages (MDMs). Both amphotericin B and ABCD caused significant reductions in uptake of conidia of Aspergillus spp. by MDMs (p < 0.01). The inhibition of germination was superior with conidia of Aspergillus fumigatus, Aspergillus niger and Aspergillus terreus isolates. Aspergillus flavus growth was significantly less inhibited of either antimycotic as compared to A. fumigatus and A. terreus (p < 0.01).We demonstrate that amphotericin B or ABCD acts as a potent inhibitor of Aspergillus germination. By contrast, treatment of MDMs with these antimycotics diminished phagocytosis of conidia in vitro.