Home About us Contact
|
Home About us Contact | ||
|
|
||
Mould Infections (mould + infections)
Selected AbstractsActivity of trans -2-hexenal against Penicillium expansum in ,Conference' pearsJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2006F. Neri Abstract Aims:, To investigate the effects of trans -2-hexenal on blue mould disease, patulin content and fruit quality in ,Conference' pears. Methods and Results:, Fruits, wounded and inoculated with Penicillium expansum or non-inoculated, were exposed to trans -2-hexenal vapour treatment (12·5 ,l l,1) at 20°C. A greater reduction of decay was obtained by treatment application 24 or 48 h after inoculation, in contrast trans -2-hexenal application 2 h after inoculation was ineffective. Fruit storage temperature (,1°C) after treatment did not affect the antifungal activity. Although 2-h exposure to trans -2-hexenal was effective in reducing blue mould, an exposure of at least 8 h was required to reduce fruit patulin content. Treatments did not affect fruit physical,chemical characteristics. After 6 days at 20°C following exposure, trans -2-hexenal residue in treated fruits was less than the natural content of the compound in unripe fruits. Conclusions:,trans -2-Hexenal treatment is effective in the reduction of blue mould infections and patulin content in Conference pears when applied 24,48 h after pathogen inoculation. Significance and Impact of the Study:,trans -2-Hexenal could be a natural alternative to fungicides in the control of P. expansum infections. Further work is needed to study the methods and conditions avoiding the persistence of off-odours and off-flavours in pears after their exposure to trans -2-hexenal vapours. [source] Age-dependent Grey Mould Susceptibility and Tissue-specific Defence Gene Activation of Grapevine Berry Skins after Infection by Botrytis cinereaJOURNAL OF PHYTOPATHOLOGY, Issue 5 2007M. Kretschmer Abstract The correlation between the degree of maturity of grapevine berries and their susceptibility to infection by the grey mould fungus Botrytis cinerea was studied. Artificial inoculation with B. cinerea conidia of detached berries from cultivars Riesling and Pinot noir revealed an increasing susceptibility during the last weeks of berry ripening. Wound inoculation resulted in increased lesion formation when compared with inoculation of non-wounded berry skins. Lesion development after non-wounding inoculation was stimulated by the addition of nutrients. Riesling berries were more readily infected than Pinot noir berries, indicating that the Riesling berry skin is more easily colonized by the grey mould fungus. Analysis of defence gene activation in the berry skin tissue revealed increased transcript levels of phenylalanine ammonium lyase and stilbene synthase after inoculation with B. cinerea conidia, while mRNA abundance of osmotin was similar in inoculated and non-inoculated tissue. Our data indicate that properties of the grape berry skin, including its ability for infection-induced defence gene activation, are important for the outcome of grey mould infections. [source] Screening method to identify inhibitors of siderophore biosynthesis in the opportunistic fungal pathogen, Aspergillus fumigatusLETTERS IN APPLIED MICROBIOLOGY, Issue 1 2009L.J. Pinto Abstract Aims:,Aspergillus fumigatus is the most common cause of airborne mould infections in immunocompromised patients worldwide. Our aim was to develop a method to identify agents that inhibit siderophore biosynthesis because this pathway is unique to the fungus and is essential for virulence. Methods and Results:, A high-throughput two-step screening assay was developed using 96-well plates in which fungal growth and siderophore production is assessed spectrophotometrically. If a compound inhibits growth only in iron-limited medium (screen 1), its effect on siderophore production is then determined (screen 2). The proof of concept was demonstrated using a known antifungal agent, amphotericin B, and a strain of A. fumigatus deficient in siderophore production. Conclusions:, The two-stage screening method clearly identified growth defects in A. fumigatus related specifically to siderophore biosynthesis. Significance and Impact of the Study:, The increasing incidence of life-threatening fungal infections has produced an urgent need for novel antifungal agents. The method described in this report will facilitate the identification of novel antifungal compounds that inhibit a pathway critical for A. fumigatus virulence and have a reduced probability of affecting host metabolism. [source] In vitro susceptibility-testing in Aspergillus speciesMYCOSES, Issue 5 2008Cornelia Lass-Flörl Summary Aspergillus species are the most common causes of invasive mould infections in immunocompromised patients. The introduction of new antifungal agents and recent reports of resistance emerging during treatment of Aspergillus infections have highlighted the need for in vitro susceptibility-testing. Various testing procedures have been proposed, including macrodilution and microdilution, agar diffusion, disc diffusion and Etest. At present, one of the most widely used assays is the M38-A reference method for filamentous fungi, published by the Clinical Laboratory Standard Institute and the Etest. Recently, the European Committee on Antimicrobial Susceptibility-testing (EUCAST) has charged its Antifungal Susceptibility-testing Subcommittee (AFST-EUCAST) with the preparation of new guidelines for in vitro susceptibility-testing of antifungals against Aspergillus spp. (EUCAST-AFST-ASPERGILLUS) defining breakpoints. This paper reviews the available methods for antifungal susceptibility-testing in Aspergillus spp. as well as the scant data regarding the clinical implications of in vitro testing. [source] Central nervous system infections by members of the Pseudallescheria boydii species complex in healthy and immunocompromised hosts: epidemiology, clinical characteristics and outcomeMYCOSES, Issue 4 2008A. Serda Kantarcioglu Summary Infections caused by members of the Pseudallescheria boydii species complex are currently among the most common mould infections. These fungi show a particular tropism for the central nervous system (CNS). We reviewed all the available reports on CNS infections, focusing on the geographical distribution, infection routes, immunity status of infected individuals, type and location of infections, clinical manifestations, treatment and outcome. A total of 99 case reports were identified, with similar percentage of healthy and immunocompromised patients (44% vs. 56%; P = 0.26). Main clinical types were brain abscess (69%), co-infection of brain tissue and/or spinal cord with meninges (10%) and meningitis (9%). The mortality rate was 74%, regardless of the patient's immune status, or the infection type and/or location. Cerebrospinal fluid culture was revealed as a not very important tool as the percentage of positive samples for P. boydii complex was not different from that of negative ones (67% vs. 33%; P = 0.10). In immunocompetent patients, CNS infection was preceded by near drowning or trauma. In these patients, the infection was characterised by localised involvement and a high fatality rate (76%). In contrast, CNS infection in immunocompromised patients was presented as rapidly progressive disseminated lesions at various degrees of evolution. Major risk factors for CNS infection were the aspiration of polluted water in near-drowning episodes in immunologically intact patients and medical immunosuppression in the remaining patient groups. As the therapeutic options were poor, the treatment was difficult in general and the prognosis was poor. [source] Disseminated Scopulariopsis brevicaulis infection in an allogeneic stem cell recipient: case report and review of the literatureCLINICAL MICROBIOLOGY AND INFECTION, Issue 5 2010A. Salmon Clin Microbiol Infect 2010; 16: 508,512 Abstract A fatal case of disseminated Scopulariopsis brevicaulis infection in an allogeneic stem cell transplant recipient is described. The patient was initially thought to have pulmonary aspergillosis, on the basis of clinical signs and antigenaemia, but Aspergillus was not isolated by culture. Scopulariopsis brevicaulis was subsequently isolated from skin and then from sputum and stool. Further investigation revealed that the infection had spread from a primary pulmonary site to the skin. A review of the literature underscores the difficulty of diagnosing infections caused by such emerging fungal pathogens and the poor outcome of immunocompromised patients with non- Aspergillus mould infections. [source] | |||||||||||||