No adverse effect of genetically modified antifungal wheat on decomposition dynamics and the soil fauna community - a field study

The cultivation of genetically modified (GM) plants has raised several environmental concerns. One of these concerns regards non-target soil fauna organisms, which play an important role in the decomposition of organic matter and hence are largely exposed to GM plant residues. Soil fauna may be directly affected by transgene products or indirectly by pleiotropic effects such as a modified plant metabolism. Thus, ecosystem services and functioning might be affected negatively. In a litterbag experiment in the field we analysed the decomposition process and the soil fauna community involved. Therefore, we used four experimental GM wheat varieties, two with a race-specific antifungal resistance against powdery mildew (Pm3b) and two with an unspecific antifungal resistance based on the expression of chitinase and glucanase. We compared them with two non-GM isolines and six conventional cereal varieties. To elucidate the mechanisms that cause differences in plant decomposition, structural plant components (i.e. C:N ratio, lignin, cellulose, hemicellulose) were examined and soil properties, temperature and precipitation were monitored. The most frequent taxa extracted from decaying plant material were mites (Cryptostigmata, Gamasina and Uropodina), springtails (Isotomidae), annelids (Enchytraeidae) and Diptera (Cecidomyiidae larvae). Despite a single significant transgenic/month interaction for Cecidomyiidae larvae, which is probably random, we detected no impact of the GM wheat on the soil fauna community. However, soil fauna differences among conventional cereal varieties were more pronounced than between GM and non-GM wheat. While leaf residue decomposition in GM and non-GM wheat was similar, differences among conventional cereals were evident. Furthermore, sampling date and location were found to greatly influence soil fauna community and decomposition processes. The results give no indication of ecologically relevant adverse effects of antifungal GM wheat on the composition and the activity of the soil fauna community.

Candida species distribution and antifungal susceptibility testing according to European Committee on Antimicrobial Susceptibility Testing and new vs. old Clinical and Laboratory Standards Institute clinical breakpoints: a 6-year prospective candidaemia survey from the fungal infection network of Switzerland

We analyzed the species distribution of Candida blood isolates (CBIs), prospectively collected between 2004 and 2009 within FUNGINOS, and compared their antifungal susceptibility according to clinical breakpoints defined by the European Committee on Antimicrobial Susceptibility Testing (EUCAST) in 2013, and the Clinical and Laboratory Standards Institute (CLSI) in 2008 (old CLSI breakpoints) and 2012 (new CLSI breakpoints). CBIs were tested for susceptiblity to fluconazole, voriconazole and caspofungin by microtitre broth dilution (Sensititre® YeastOne™ test panel). Of 1090 CBIs, 675 (61.9%) were C. albicans, 191 (17.5%) C. glabrata, 64 (5.9%) C. tropicalis, 59 (5.4%) C. parapsilosis, 33 (3%) C. dubliniensis, 22 (2%) C. krusei and 46 (4.2%) rare Candida species. Independently of the breakpoints applied, C. albicans was almost uniformly (>98%) susceptible to all three antifungal agents. In contrast, the proportions of fluconazole- and voriconazole-susceptible C. tropicalis and F-susceptible C. parapsilosis were lower according to EUCAST/new CLSI breakpoints than to the old CLSI breakpoints. For caspofungin, non-susceptibility occurred mainly in C. krusei (63.3%) and C. glabrata (9.4%). Nine isolates (five C. tropicalis, three C. albicans and one C. parapsilosis) were cross-resistant to azoles according to EUCAST breakpoints, compared with three isolates (two C. albicans and one C. tropicalis) according to new and two (2 C. albicans) according to old CLSI breakpoints. Four species (C. albicans, C. glabrata, C. tropicalis and C. parapsilosis) represented >90% of all CBIs. In vitro resistance to fluconazole, voriconazole and caspofungin was rare among C. albicans, but an increase of non-susceptibile isolates was observed among C. tropicalis/C. parapsilosis for the azoles and C. glabrata/C. krusei for caspofungin according to EUCAST and new CLSI breakpoints compared with old CLSI breakpoints.

Time Course of Antibiotic and Antifungal Concentrations in Corneal Organ Culture.

PURPOSE Contamination with bacteria and/or fungi is a serious complication in organ-cultured corneas. Hence, antibiotic and antifungal agents are added to the culture medium. The concentration of different antimicrobial and antifungal additives to the media over time has so far not been investigated in detail and is the aim of this study. METHODS Nine human fresh corneoscleral discs were stored in corneal culture medium consisting of 2% fetal bovine serum and minimal essential medium. In addition, the culture medium contained 1200 μg/mL penicillin G, 25 μg/mL amphotericin B, 120 μg/mL streptomycin, and 100 μg/mL voriconazole. The concentration of amphotericin B used was 10 times higher than in clinical routine to facilitate its detection. The cultures were kept at 37°C for 28 days. At days 0, 7, 14, 21, and 28, samples of the culture medium were harvested for analysis of antimicrobial concentrations by liquid chromatography and electrospray ionization tandem mass spectrometry. RESULTS During corneal storage, the concentration of all antibiotics and antifungal agents declined significantly. By day 28, penicillin G was reduced to 14% of the original concentration. Amphotericin B and streptomycin retained approximately 60% of the original concentration to the end of the experiment and voriconazole maintained stable concentrations after an initial decline to approximately 80% at 7 days. CONCLUSIONS Throughout the entire storage period, the concentrations of penicillin G, streptomycin, and voriconazole exceeded the minimum inhibitory concentrations of all common contaminants, obviating the need for a change of the medium for antimicrobial reasons. Based on the minimum inhibitory concentrations and our findings, the initial concentration of amphotericin B should be raised to 5 μg/mL.

Role of complement and Fc{gamma} receptors in the protective activity of the long pentraxin PTX3 against Aspergillus fumigatus

Pentraxin 3 (PTX3) is a soluble pattern recognition molecule playing a nonredundant role in resistance against Aspergillus fumigatus. The present study was designed to investigate the molecular pathways involved in the opsonic activity of PTX3. The PTX3 N-terminal domain was responsible for conidia recognition, but the full-length molecule was necessary for opsonic activity. The PTX3-dependent pathway of enhanced neutrophil phagocytic activity involved complement activation via the alternative pathway; Fc receptor (Fc R) IIA/CD32 recognition of PTX3-sensitized conidia and complement receptor 3 (CR3) activation; and CR3 and CD32 localization to the phagocytic cup. Gene targeted mice (ptx3, FcR common chain, C3, C1q) validated the in vivo relevance of the pathway. In particular, the protective activity of exogenous PTX3 against A fumigatus was abolished in FcR common chain-deficient mice. Thus, the opsonic and antifungal activity of PTX3 is at the crossroad between complement, complement receptor 3-, and Fc R-mediated recognition. Because short pentraxins (eg, C-reactive protein) interact with complement and Fc R, the present results may have general significance for the mode of action of these components of the humoral arm of innate immunity.

Voriconazole-induced phototoxicity in children

Voriconazole is used in antifungal prophylaxis. We performed a retrospective review of immunocompromised children receiving prophylaxis with voriconazole during major hospital renovation, who developed phototoxic skin reactions. The overall incidence of phototoxic skin reactions was 33%. A voriconazole dose of ≥6 mg/kg of body weight per dose twice daily was associated with a significantly greater risk to develop phototoxic skin reactions compared with lower doses.

Diagnosis and treatment of mucormycosis in patients with hematological malignancies: guidelines from the 3rd European Conference on Infections in Leukemia (ECIL 3)

Mucormycosis is an emerging cause of infectious morbidity and mortality in patients with hematologic malignancies. However, there are no recommendations to guide diagnosis and management. The European Conference on Infections in Leukemia assigned experts in hematology and infectious diseases to develop evidence-based recommendations for the diagnosis and treatment of mucormycosis. The guidelines were developed using the evidence criteria set forth by the American Infectious Diseases Society and the key recommendations are summarized here. In the absence of validated biomarkers, the diagnosis of mucormycosis relies on histology and/or detection of the organism by culture from involved sites with identification of the isolate at the species level (no grading). Antifungal chemotherapy, control of the underlying predisposing condition, and surgery are the cornerstones of management (level A II). Options for first-line chemotherapy of mucormycosis include liposomal amphotericin B and amphotericin B lipid complex (level B II). Posaconazole and combination therapy of liposomal amphotericin B or amphotericin B lipid complex with caspofungin are the options for second line-treatment (level B II). Surgery is recommended for rhinocerebral and skin and soft tissue disease (level A II). Reversal of underlying risk factors (diabetes control, reversal of neutropenia, discontinuation/taper of glucocorticosteroids, reduction of immunosuppressants, discontinuation of deferroxamine) is important in the treatment of mucormycosis (level A II). The duration of antifungal chemotherapy is not defined but guided by the resolution of all associated symptoms and findings (no grading). Maintenance therapy/secondary prophylaxis must be considered in persistently immunocompromised patients (no grading).

Invasive sphenoidal aspergillosis: successful treatment with sphenoidotomy and voriconazole

Treatment of invasive sphenoidal aspergillosis is surgical, followed by antifungal therapy, mostly amphotericin B. To optimize the adjuvant antifungal treatment, which is often limited by severe side effects, the new triazole antifungal agent voriconazole with broad coverage of fungal pathogens including Aspergillus was investigated in a study of 4 patients with clinical, radiological and histological signs of invasive sphenoidal aspergillosis. They first underwent endoscopic sphenoidotomy with drainage and extraction of the fungal mass. Postoperatively, 2 patients were immediately treated with voriconazole. Two patients initially received amphotericin B; but this treatment had to be stopped because of acute renal toxicity. Finally, all patients were treated orally with 200 mg voriconazole twice a day for 12-14 weeks. After this combined treatment all patients were asymptomatic and there were no endoscopic or radiological signs of residual fungal disease. The only side effects were nausea in one and transient visual disturbances in 2 other patients. In the 4 patients presented and treated, voriconazole was shown to be effective and less toxic than amphotericin B in adjuvant treatment of invasive sphenoidal aspergillosis. Copyright (c) 2007 S. Karger AG, Basel.

Amphotericin B nasal spray has no effect on nasal polyps

Nasal polyps and chronic rhinosinusitis are the products of an inflammatory process. Recently, fungal involvement has been thought to stimulate the development of polyps, and administration of antifungal agents was therefore considered a potential treatment. Several studies have been published indicating amphotericin B as an effective treatment for nasal polyps and chronic rhinosinusitis. The aim of our investigation was to evaluate the efficacy of intranasal applied amphotericin B on the growth of nasal polyps in a three-month, prospective, open trial. Our results show that nasal amphotericin B spray is not effective for nasal polyps and may even cause deterioration.

Percutaneous endoscopic gastrostomy in children on peritoneal dialysis

OBJECTIVE: Insertion of percutaneous endoscopic gastrostomies (PEG) in patients on chronic peritoneal dialysis (PD) has been reported to be contraindicated due to an increased risk of morbidity and mortality. However, no systematic survey on this topic has yet been published. DESIGN: Retrospective multicenter study. SETTING: 23 pediatric dialysis units associated with the working group Arbeitsgemeinschaft für Pädiatrische Nephrologie (APN). DATA SOURCE: A structured questionnaire on clinical details of PD patients who had undergone PEG insertion or open gastrostomy (OG) since 1994 was distributed to all pediatric dialysis units of the APN. RESULTS: 27 PD patients (20 males) from 12 centers in whom PEG insertion was performed after Tenckhoff catheter introduction were evaluated. Age at intervention ranged from 0.25 to 10.9 years (median 1.3 years). Most patients were malnourished, with standard deviation score (SDS) for body weight between -4.2 and -0.6 (median -2.2). Major complications were early peritonitis < 7 days after PEG in 10/27 (37%) patients, episodes of fungal peritonitis in 7/27 (26%) patients, 4 cessations of PD and change to hemodialysis, and 2 associated deaths. However, in 14 patients, no such problems were encountered and, in 4 patients, early peritonitis effectively treated with intraperitoneal antibiotics was the only major complication. Thus, in 18/27 (67%) patients, PD was successfully reinitiated shortly after PEG insertion. Among all participating centers, only two OG procedures were reported during the study period, illustrating a clear preference for the PEG over the OG procedure among members of the APN. CONCLUSION: PEG insertion following PD initiation carries a high risk for fungal peritonitis and potential PD failure; however, complication rates in this largest reported series were lower than previously described. Antibiotic and antifungal prophylaxis, withholding PD for 2 - 3 days, and gastrostomy placement by an experienced endoscopy team are suggested precautions for lowering the risk of associated complications. When gastrostomy placement does not occur prior to or at the time of initiating PD, the risks and benefits of percutaneous versus open placement must be carefully weighed.

Calcineurin inhibition or mutation enhances cell wall inhibitors against Aspergillus fumigatus

Calcineurin mutation or inhibition enhanced the antifungal morphological effect of cell wall inhibitors caspofungin or nikkomycin Z against Aspergillus fumigatus. Quantification of 1,3-beta-d-glucan revealed decreased amounts in the calcineurin A (DeltacnaA) mutant. Calcineurin can be an excellent adjunct therapeutic target in combination with other cell wall inhibitors against A. fumigatus.

Candida parapsilosis endocarditis: a comparative review of the literature

Fungal endocarditis (FE) is an uncommon disease, and while accounting for only 1.3-6% of all cases of infectious endocarditis, it carries a high mortality risk. Although Candida albicans represents the main etiology of FE, C. parapsilosis is the most common non-albicans species. We report the case of a 32-year-old man with a history of prior intravenous drug (IVD) use hospitalized with endocarditis due to C. parapsilosis and review all 71 additional cases documented in the literature. A retrospective analysis of the 72 C. parapsilosis cases compared to 52 recently reviewed cases of C. albicans endocarditis was conducted to identify organism-specific clinical peculiarities. The most common predisposing factor for C. parapsilosis endocarditis (41/72; 57.4%) involved prosthetic valves followed by IVD use (12/72; 20%). Peripheral embolic and/or hemorrhagic events occurred in 28/64 (43.8%) patients, mostly in cerebral and lower limb territories. Overall mortality was 41.7%. Combined surgical and clinical treatment was associated with a lower mortality. Few patients received the newer antifungal agents, and it would appear that more experience is required for their use in the treatment of C. parapsilosis endocarditis.

Topical caspofungin for treatment of keratitis caused by Candida albicans in a rabbit model

Candida albicans is the most frequent cause of fungal keratitis in temperate regions. Caspofungin has potent activity against Candida spp. in a variety of clinical settings. Little is known, however, about its activity against fungal keratitis. We compared the efficacy of topical caspofungin with that of topical amphotericin B (AMB) in a rabbit model of experimental keratomycosis. Keratitis was induced with a standardized inoculum of Candida albicans (SC 5314) placed on the debrided cornea. Twenty-four hours after infection, animals were randomly assigned to treatment with 0.15% caspofungin, 0.5% caspofungin, 0.15% AMB, and a saline control (n = 12 rabbits in each group). For the first 12 h, treatment was repeated every 30 min and, after a 12-h pause, was resumed at hourly intervals for another 12 h. The animals were examined and killed 12 h after administration of the last dose. Treatment effects were evaluated by clinical assessment, fungal culture, and histopathology. Drug treatment significantly reduced corneal fungal recovery from 3.78 log10 CFU in saline-treated animals to 2.97, 1.76, and 1.18 log10 CFU in animals treated with 0.15% caspofungin, 0.5% caspofungin, and 0.15% AMB, respectively. By histopathology, the mean hyphal density was significantly lower in the corneas of treated animals than in those of the controls; there was no difference in hyphal densities between the different treatment groups. The depth of corneal invasion was not significantly reduced by the antifungal treatments. By clinical assessment, keratitis progressed in animals treated with saline, whereas disease progression was inhibited by all drug treatment regimens. In our rabbit model, 0.5% caspofungin was as effective as 0.15% AMB for the topical treatment of Candida keratitis. The potential clinical efficacy of caspofungin awaits further investigation.

Treatment of intestinal and hepatic mucormycosis in an immunocompromized child

During ALL chemotherapy, a 4-year-old patient presented with febrile neutropenia and abdominal pain. Ultrasound examinations were repeatedly normal. Computerized tomography on day 7 demonstrated appendicitis and multiple hepatic foci identified as mucormycosis (Absidia corymbifera). Successful outcome was achieved by aggressive re-surgery, long-term antifungal therapy with serum level-monitored posaconazole, and recovery of neutrophil counts. Considering the interference of posaconazole with CYP3A4, vincristine was administered during 72 hr posaconazole windows. Pediatric intestinal mucormycosis, still associated with a >70% case-fatality rate, calls for early imaging and surgery to establish the diagnosis, reduce the fungal mass, and provide a rationale for using posaconazole.