Astrid Mayr

Epidemiology and outcome of infections due to Aspergillus terreus: 10-year single centre experience.

Aspergillus terreus, a less common pathogen, appears to be an emerging cause of infection at our institution, the Medical University Hospital of Innsbruck. Thus the epidemiology and outcome of A. terreus infections over the past 10 years was assessed. We analysed 67 cases of proven invasive aspergillosis (IA) according to the European Organisation for Research and Treatment of Cancer/Mycoses Study Group criteria, investigated antifungal susceptibility of amphotericin B (AMB), voriconazole and caspofungin and performed molecular typing of A. terreus. Patients with proven IA caused by A. terreus (n = 32) and non‐A. terreus (n = 35) were evaluated. The two groups were comparable in terms of age, gender, underlying disease, antifungal prophylaxis and duration of neutropenia (P > 0·05). Leukaemia was the most common underlying malignancy. Fungal dissemination occurred in 63% of the patients. Aspergillus terreus infections were associated with a lower response rate to AMB therapy (20%), compared with 47% for patients with non‐A. terreus infections (P < 0·05). In vitro, A. terreus was found to be resistant to AMB and molecular typing discriminated between patients isolates, showing a high strain diversity with 26 distinct types (I‐XXVI) identified by combination of three primers. Aspergillus terreus infections displayed evidence of AMB resistance in vitro and in vivo and were associated with a high rate of dissemination and poor outcome; A. terreus causes systemic infections of endemic character in Tyrol, Austria. The onset of A. terreus infection depends not on the degree of immunosuppression but on environmental Aspergillus spp. exposure.

Activities of Antifungal Agents against Yeasts and Filamentous Fungi: Assessment according to the Methodology of the European Committee on Antimicrobial Susceptibility Testing

ABSTRACT We compared the activities of antifungal agents against a wide range of yeasts and filamentous fungi. The methodology of the European Committee on Antimicrobial Susceptibility Testing (EUCAST) for yeasts and spore-forming molds was applied; and a total of 349 clinical isolates of Candida spp., other yeast species, Aspergillus spp., and nondermatophyte non-Aspergillus spp. were investigated. The average geometric mean (GM) of the MICs of the various drugs for Candida spp. were as follows: amphotericin B (AMB), 0.55 μg/ml; liposomal amphotericin B (l-AMB); 0.35 μg/ml; itraconazole (ITC), 0.56 μg/ml; voriconazole (VRC), 0.45 μg/ml; posaconazole (POS), 0.44 μg/ml; and caspofungin (CPF), 0.45 μg/ml. The data indicated that the majority of Candida spp. were susceptible to the traditional and new antifungal drugs. For Aspergillus spp., the average GM MICs of AMB, l-AMB, ITC, VRC, POS, and CPF were 1.49 μg/ml, 1.44 μg/ml, 0.65 μg/ml, 0.34 μg/ml, 0.25 μg/ml, and 0.32 μg/ml, respectively. For the various zygomycetes, the average GM MICs of AMB, l-AMB, ITC, and POS were 1.36 μg/ml, 1.42 μg/ml, 4.37 μg/ml, and 1.65 μg/ml, respectively. Other yeastlike fungi and molds displayed various patterns of susceptibility. In general, the minimal fungicidal concentrations were 1 to 3 dilutions higher than the corresponding MICs. POS, AMB, and l-AMB showed activities against a broader range of fungi than ITC, VRC, and CPF did. Emerging pathogens such as Saccharomyces cerevisiae and Fusarium solani were not killed by any drug. In summary, the EUCAST data showed that the in vitro susceptibilities of yeasts and filamentous fungi are variable, that susceptibility occurs among and within various genera and species, and that susceptibility depends on the antifungal drug tested. AMB, l-AMB, and POS were active against the majority of pathogens, including species that cause rare and difficult-to-treat infections.

In vitro susceptibility testing in fungi: a global perspective on a variety of methods

Candida and Aspergillus species are the most common causes of invasive fungal infections in immunocompromised patients. The introduction of new antifungal agents and recent reports of resistance emerging during treatment have highlighted the need for in vitro susceptibility testing. For some drugs, there is a supporting in vitro–in vivo correlation available from studies of clinical efficacy. Both intrinsic and emergent antifungal drug resistance are encountered. Various testing procedures have been proposed, including macrodilution and microdilution, agar diffusion, disk diffusion and Etest. Early recognition of infections caused by pathogens that are resistant to one or more antifungals is highly warranted to optimise treatment and patient outcome.

Short Communication - Antifungal properties of 5-hydroxytryptamine (serotonin) against Aspergillus spp. in vitro

This study shows that 5-hydroxytrypatmine (5-HT, serotonin) is fungicidal towards conidia and hyphae of clinical isolates of Aspergillus (A.) fumigatus, A. flavus and A. terreus. The minimal fungicidal concentrations for Aspergillus conidia and hyphae ranged between 14.68 to 117.5 mM and 29.37 to 235 mM during 24 and 48 h of incubation. Several serotonin receptor antagonists (5-HT2, 5-HT3) studied in vitro did not influence antifungal activity.

Caspofungin: when and how? The microbiologist’s view

The echinocandins are antifungal agents, which act by inhibiting the synthesis of β‐(1,3)‐d‐glucan, an integral component of fungal cell walls. Caspofungin, the first approved echinocandin, demonstrates good in vitro and in vivo activity against a range of Candida species and is an alternative therapy for Aspergillus infections. Caspofungin provides an excellent safety profile and is therefore favoured in patients with moderately severe to severe illness, recent azole exposure and in those who are at high risk of infections due to Candida glabrata or Candida krusei. In vivo/in vitro resistance to caspofungin and breakthrough infections in patients receiving this agent have been reported for Candida and Aspergillus species. The types of pathogens and the frequency causing breakthrough mycoses are not well delineated. Caspofungin resistance resulting in clinical failure has been linked to mutations in the Fksp subunit of glucan synthase complex. European Committee for Antimicrobial Susceptibility Testing and Clinical and Laboratory Standards Institute need to improve the in vitro susceptibility testing methods to detect fks hot spot mutants. Caspofungin represents a significant advance in the care of patients with serious fungal infections.

Diagnosing invasive fungal diseases - limitations of microbiological diagnostic methods.

BACKGROUND Invasive fungal infections (IFD) are a principal cause of morbidity and mortality in immunosuppressed patients, with case fatality rates ranging from 30 - 80% in neutropenic patients. This results at least partly from difficulties in obtaining a reliable and early diagnosis. Conventional methods, for example culture-based methods, may be difficult and are often delayed. Serological tests such as the galactomannan enzyme immunoassay are at present most promising for diagnosing invasive aspergillosis; however, sensitivity and specificity vary within the studies. Similar data are shown for Aspergillus detection by polymerase chain reaction. OBJECTIVE The aim of this article is to review classical and new diagnostic tools for the identification of invasive fungal infections and to summarize current limitations of these methods. CONCLUSION The early diagnosis of IFD still remains a problem as existing tools lack sensitivity or specificity. Therefore, the combination of microscopy, culture-based methods, and serological and molecular techniques is necessary to allow early detection of IFD.

Nosocomial outbreak of extensively drug-resistant Pseudomonas aeruginosa associated with aromatherapy

HighlightsAn increase of extensively drug‐resistant Pseudomonas aeruginosa (XDR‐PA) took place in a surgical intensive care unit.Molecular typing confirmed a nosocomial outbreak was present.Transmission of XDR‐PA had likely occurred via patient care oil for aromatherapy.Significance of exogenous sources for XDR‐PA and importance of strict infection control are emphasized. &NA; An increase of extensively drug‐resistant Pseudomonas aeruginosa (XDR‐PA) in various clinical specimens among intensive care unit patients (n = 7) initiated an outbreak investigation consisting of patient data analyses, control of adherence to infection control guidelines, microbiologic surveys, and molecular‐based studies. XDR‐PA was detected in a jointly used aroma‐oil nursing bottle for aromatherapy. We implemented the restriction of oil sharing among patients. Hence, the outbreak was controlled successfully.

Outbreak report: a nosocomial outbreak of vancomycin resistant enterococci in a solid organ transplant unit

BackgroundVancomycin resistant enterococci (VRE) are an emerging problem in health care settings. The purpose of the investigation was to assess the extent of the outbreak including environmental contamination and to limit further transmission.MethodsWe used retrospective patient and laboratory data including pulse field gel electrophoresis (PFGE) typing and virulence and resistance gene analysis. For comparison of medians the Mann-Whitney and for comparison of proportions the Fisher exact tests were used.ResultsPFGE typing of VRE strains of an outbreak of 15 VRE cases in a solid transplant unit revealed that nine of the cases belonged to one identical pattern (A), which was only found twice in the environment. Eleven further positive environmental samples showed a different, but identical PFGE pattern E. Only one patient was infected with this environmental strain.Two of nine (22.2%) PFGE A, but nine of eleven (81.2%) PFGE E samples were positive for gelatinase E (p = 0.01), which is described as enhancing biofilm production, suggesting a survival benefit for this strain on inanimate surfaces.ConclusionRoutine disinfection was not able to stop the cluster, but after repeated enforcement of the infection prevention and control (IPC) bundle such as training, strict adherence to hand hygiene and surface disinfection no further cases were observed. We conclude that certain VRE strains predominate in the environment whereas others predominate in humans. Enforcement of the IPC bundle is essential for controlling VRE outbreaks and reducing further transmission.

Self-disinfecting surfaces and the activity against Staphyloccocus aureus ATCC 6538 under real life conditions

Environmental surface contamination provides a potential reservoir for pathogens to cause infections. As such, self-disinfecting surfaces have been developed to possibly reduce exogenous transmission. Five different self-disinfecting surfaces were evaluated for activity against Staphylococcus aureus ATCC 6538 under real-life conditions using the dry inoculation method. Various antimicrobial effects were detected. However, following disinfection with alcoholic wipes, these effects disappeared. Further development is necessary to produce self-disinfecting surfaces that are stable in the presence of hospital disinfectants, as it is impossible to guarantee that self-disinfecting surfaces in healthcare settings will not be exposed to disinfectants.

Hygienemaßnahmen bei Creutzfeldt-Jakob Erkrankungen

Die Creutzfeldt-Jakob-Krankheit zählt zu den transmissiblen spongiformen Enzephalopathien (TSE) oder Prionenerkrankungen, das sind stets letal verlaufende neurodegenerative Erkrankungen, die bei Menschen und auch bei Säugetieren vorkommen (Tab. 1). Sie werden durch sogenannte Prionen, infektiöse Eiweißpartikel, übertragen.