British Society for Medical Mycology proposed standards of care for patients with invasive fungal infections

Zygomycosis in two hematologic cases

Zygomycosis are invasive mould infections, rarely diagnosed in hematologic patients. Most of the cases published are in patients with prolonged neutropenia, along with other risk factors such as the use of prior broad-spectrum antibiotics (including new antifungal agents, such as voriconazole), diabetes mellitus (with or without ketoacidosis), malnutrition, iron overload (with or without the use of deferoxamine). These infections have poor prognosis due to the involvement of vital anatomic structures and late diagnosis. Until recent years, the treatment was based on high doses of amphotericin B plus surgical debridement. Here we present two patients with hematologic diseases (one with leukemia, the second with aplastic anemia) with an impaired immune system and the diagnosis of zygomycosis. The survival of one of them was mainly due to early diagnosis and surgical debridement; unfortunately the second was misdiagnosed as an extensive ecchymosis due to thrombocytopenia and died with CNS involvement.

Management of fungal infections in the intensive care unit: a survey of UK practice

BACKGROUND

Candida species are a common cause of nosocomial bloodstream infection. Such infections commonly affect patients in the intensive care unit (ICU) and carry a high mortality. There are published guidelines for the management of fungal infections, but there are no data on the usual management of invasive Candida infections in UK ICUs.

METHODS

An electronic survey was sent by email to a representative clinician in 236 ICUs, over 90% of units in the UK. Questions related to the institution of empirical therapy and to the management of proven candidaemia.

RESULTS

There were 72 responses. A minority of units follow a policy regarding the management of these infections but the involvement of microbiologists is usual. Empirical therapy is used in 85.9% of units, often for patients perceived to be at high risk. Fluconazole is the most commonly used antifungal agent, both for empirical therapy and for the treatment of proven candidaemia. For candidaemic patients, 73.9% of ICUs frequently or always remove central venous catheters within 48 h, while 15.1% frequently or always arrange ophthalmology review.

CONCLUSIONS

Management of fungal infections is relatively consistent among responding units. However, recent developments in the field have not yet been incorporated into standard practice. Adherence to published guidelines could be improved, potentially reducing morbidity and mortality from these common infections.

Mixed mould species in laboratory cultures of respiratory specimens: how should they be reported, and what are the indications for susceptibility testing?

AIMS

To investigate how clinical microbiology laboratories should report and interpret mixed mould isolates including Aspergillus species from clinical samples and the criteria for susceptibility testing of the isolates.

METHODS

Retrospectively collected data from our laboratory information system of moulds isolated between January 2005 and December 2007. Patient case notes were also reviewed.

RESULTS

A total of 502 isolates (from 273 patients) were found. 20 patients with clinical diagnosis of a probable fungal infection had mixed Aspergillus species.

CONCLUSIONS

In most instances, the isolation of Aspergillus species from non-sterile sites does not represent clinical disease, but only colonisation/contamination. However, for high-risk patients including transplant recipients, a positive culture is associated with invasive disease. Our tertiary centre routinely reports single fungal isolates and mixed cultures with appropriate comments, and those considered significant will also have susceptibility testing carried out. The correlation of culture results with clinical features can differentiate between invasive disease and contamination.

Candida tropicalis in human disease

Candida tropicalis is one of the more common Candida causing human disease in tropical countries; the frequency of invasive disease varies by geography causing 3--66% of candidaemia. C. tropicalis is taxonomically close to C. albicans and shares many pathogenic traits. C. tropicalis is particularly virulent in neutropenic hosts commonly with hematogenous seeding to peripheral organs. For candidaemia and invasive candidiasis amphotericin B or an echinocandin are recommended as first-line treatment, with extended-spectrum triazoles acceptable alternatives. Primary fluconazole resistance is uncommon but may be induced on exposure. Physicians in regions where C. tropicalis is common need to be mindful of this lesser-described pathogen.

Improved clinical laboratory identification of human pathogenic yeasts by matrix-assisted laser desorption ionization time-of-flight mass spectrometry

The key to therapeutic success with yeast infections is an early onset of antifungal treatment with an appropriate drug regimen. To do this, yeast species identification is necessary, but conventional biochemical and morphological approaches are time-consuming. The recent arrival of biophysical methods, such as matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), in routine diagnostic laboratories holds the promise of significantly speeding up this process. In this study, two commercially available MALDI-TOF MS species identification systems were evaluated for application in clinical diagnostics, using a geographically diverse collection of 1192 clinical yeast and yeast-like isolates. The results were compared with those of the classical differentiation scheme based on microscopic and biochemical characteristics. For 95.1% of the isolates, all three procedures consistently gave the correct species identification, but the rate of misclassification was greatly reduced in both MALDI-TOF MS systems. Furthermore, several closely related species (e.g. Candida orthopsilosis/metapsilosis/parapsilosis or Candida glabrata/bracarensis) could be resolved by both MALDI-TOF MS systems, but not by the biochemical approach. A significant advantage of MALDI-TOF MS over biochemistry in the recognition of isolates novel to the system was observed. Although both MALDI-TOF MS systems employed different approaches in the database structure and showed different susceptibilities to errors in database entries, these were negligible in terms of clinical usefulness. The time-saving benefit of MALDI-TOF MS over biochemical identification will substantially improve fungal diagnostics and patient treatment.

[Management of candidemia and invasive candidiasis]

Candida species is the fourth most common cause of bloodstream infection and is the leading cause of invasive fungal infection among hospitalized patients. Acute disseminated candidiasis remains a life-threatening disease that now occurs mainly in intensive care units hospitalized patients. Delay in treatment of Candida bloodstream infections could be minimized by the development of more rapid and sensitive diagnostic techniques for the identification of Candida bloodstream infections. Current guidelines for the management of invasive candidiasis recommend fluconazole or an echinocandin as the primary therapeutic option. The optimal choice of the antifungal agent should depend on local epidemiology, prior antifungal therapy and patient's characteristics.

Determination of urinary D-/L-arabinitol ratios as a biomarker for invasive candidiasis in children with cardiac diseases

A non-invasive, non-culture-based method of determining urinary D-/L-arabinitol (D-/L-ARA) ratios was investigated as a tool for the diagnosis of invasive candidiasis in nosocomial paediatric infection cases. The study encompassed 138 children aged 4 days to 16 years (mean ± SD=1.6 ± 4.2 years) with congenital heart defects (91.4%) or with rhythm disorders or circulatory failure (8.6%). ARA enantiomers were detected by GC using an electron capture detector. Positive D-/L-ARA ratios were found for 11/11 patients with proven candidiasis and 17/19 patients with clinically suspected invasive candidiasis. Thirty children were undergoing antifungal chemotherapy. D-/L-ARA ratios (mean ± SD) were 2.601 ± 0.544 in hospitalized cardiac patients without fungal infection and 5.120 ± 1.253 in those receiving antifungal therapy (P<0.001). The sensitivity of the method was 100%, the specificity 97.2%, the positive predictive value was 78.6% and the negative predictive value was 100%.

An uncommon case of systemic Mucormycosis associated with spinal cord infarction in a recently diagnosed diabetic

Mucormycosis is a relatively rare, opportunistic, invasive infection caused by various members of the Phycomycetes class [from Greek phyko- seaweed; having a plant body], an extensive taxonomy introduced in 1956 to enlarge the class of Zygomycetes. These filamentous fungi have a worldwide distribution and are capable of rapid growth and thermotolerance of human body temperature. Infection typically occurs in seriously compromised patients (i.e. diabetic ketoacidosis, hematologic malignancies, immunosuppressive disorders, end-stage renal disease, solid-organ or bone-marrow transplantation) and can be acute or fulminant, as well as indolent and chronic. In this paper we describe a case of cutaneous mucormycosis that occurred in a 54-year-old diabetic woman and evolved into a disseminated form, leading to an uncommon spinal cord infarction and consequent paraparesis. Our case suggests the importance of suspecting a mucormycosis infection in patients with decompensated diabetes mellitus, even without ketoacidosis.

Micafungin: a review of its use in the prophylaxis and treatment of invasive Candida infections in pediatric patients

Intravenous micafungin (Mycamine; Funguard) is an echinocandin indicated in Japan and the EU for the treatment of pediatric patients (including neonates) with invasive candidiasis and as prophylaxis against Candida infection in pediatric patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT). In the EU, micafungin is also indicated in pediatric patients who are expected to have neutropenia for >/=10 days. In Japan, children may also receive micafungin for the treatment of, or as prophylaxis against, invasive Aspergillus infection. Micafungin is not currently approved for use in pediatric patients in the US. Micafungin has very good antifungal activity against a wide range of Candida spp. in vitro. It has a favorable pharmacokinetic profile allowing for once-daily administration, has few drug-drug interactions, and reports of resistance are rare. The results of pediatric substudies indicate that intravenous micafungin is effective in a majority of patients for the treatment of candidemia and other types of invasive candidiasis, and provides effective prophylaxis against invasive fungal infections in pediatric patients undergoing HSCT. The tolerability profile of micafungin in pediatric patients was generally acceptable. In the EU, micafungin is indicated for use when other antifungal medications are not appropriate. Therefore, micafungin provides an alternative to other antifungal agents used in the management of candidemia and invasive candidiasis in pediatric patients, or as prophylaxis against fungal infections in pediatric patients undergoing HSCT.

Current Molecular Diagnostic Approaches to Systemic Infections withAspergillusSpecies in Patients with Hematological Malignancies

Within the recent years, novel molecular methods, especially PCR assays, have been developed to improve the diagnosis of invasive aspergillosis in patients with malignant hematological diseases being at high risk for this life-threatening infection. Early diagnosis and treatment are essential for adequate therapeutical management, which however, often remains difficult since most of the diagnostic tools used clinically at present either lack specificity or acceptable sensitivity. The clinical value, advantages and remaining problems of recently developed molecular approaches to detect the emerging fungal pathogen are reviewed.

Pseudomembranous tracheobronchitis caused by Aspergillus in immunocompromised patients

We report 2 cases of Aspergillus pseudomembranous tracheobronchitis in patients with diabetes. The first patient succumbed to progressive obstructive respiratory failure despite mechanical ventilation and antifungal therapy. However, the second patient survived. Aspergillus tracheobronchitis should be considered in immuno-compromised patients presenting with cough, chest pain, fever, dyspnea and upper airway obstruction. Early bronchoscopy and histologic examination should be performed. Early, appropriate treatment may be life saving.

Liposomal amphotericin B: a review of its use as empirical therapy in febrile neutropenia and in the treatment of invasive fungal infections

Liposomal amphotericin B (AmBisome) is a lipid-associated formulation of the broad-spectrum polyene antifungal agent amphotericin B. It is active against clinically relevant yeasts and moulds, including Candida spp., Aspergillus spp. and filamentous moulds such as Zygomycetes, and is approved for the treatment of invasive fungal infections in many countries worldwide. It was developed to improve the tolerability profile of amphotericin B deoxycholate, which was for many decades considered the gold standard of antifungal treatment, despite being associated with infusion-related events and nephrotoxicity. In well controlled trials, liposomal amphotericin B had similar efficacy to amphotericin B deoxycholate and amphotericin B lipid complex as empirical therapy in adult and paediatric patients with febrile neutropenia. In addition, caspofungin was noninferior to liposomal amphotericin B as empirical therapy in adult patients with febrile neutropenia. For the treatment of confirmed invasive fungal infections, liposomal amphotericin B was more effective than amphotericin B deoxycholate treatment in patients with disseminated histoplasmosis and AIDS, and was noninferior to amphotericin B deoxycholate in patients with acute cryptococcal meningitis and AIDS. In adults, micafungin was shown to be noninferior to liposomal amphotericin B for the treatment of candidaemia and invasive candidiasis. Data from animal studies suggested that higher dosages of liposomal amphotericin B might improve efficacy; however, in the AmBiLoad trial in patients with invasive mould infection, there was no statistical difference in efficacy between the standard dosage of liposomal amphotericin B 3 mg/kg/day and a higher 10 mg/kg/day dosage, although the standard dosage was better tolerated. Despite being associated with fewer infusion-related adverse events and less nephrotoxicity than amphotericin B deoxycholate and amphotericin B lipid complex, liposomal amphotericin B use is still limited to some extent by these adverse events. Both echinocandins were better tolerated than liposomal amphotericin B. The cost of liposomal amphotericin B therapy may also restrict its use, but further pharmacoeconomic studies are required to fully define its cost effectiveness compared with other antifungal agents. Based on comparative data from well controlled trials, extensive clinical experience and its broad spectrum of activity, liposomal amphotericin B remains a first-line option for empirical therapy in patients with febrile neutropenia and in those with disseminated histoplasmosis, and is an option for the treatment of AIDS-associated cryptococcal meningitis, and for invasive Candida spp. or Aspergillus spp. infections. Amphotericin B, a macrocyclic, polyene antifungal agent, is thought to act by binding to ergosterol, the principal sterol in fungal cell membranes and Leishmania cells. This results in a change in membrane permeability, causing metabolic disturbance, leakage of small molecules and, as a consequence, cell death. In vitro and in vivo studies have shown that liposomal amphotericin B remains closely associated with the liposomes in the circulation, thereby reducing the potential for nephrotoxicity and infusion-related toxicity associated with conventional amphotericin B. Amphotericin B shows very good in vitro activity against a broad spectrum of clinically relevant fungal isolates, including most strains of Candida spp. and Aspergillus spp., and other filamentous fungi such as Zygomycetes. Liposomal amphotericin B has proven effective in various animal models of fungal infections, including those for candidiasis, aspergillosis, fusariosis and zygomycosis. Liposomal amphotericin B also shows immunomodulatory effects, although the mechanisms involved are not fully understood, and differ from those of amphotericin B deoxycholate and amphotericin B colloidal dispersion. In adult patients with febrile neutropenia, intravenous liposomal amphotericin B has nonlinear pharmacokinetics, with higher than dose-proportional increases in exposure being consistent with reticuloendothelial saturation and redistribution of amphotericin B in the plasma compartment. Liposomal amphotericin B is rapidly and extensively distributed after single and multiple doses, with steady-state concentrations of amphotericin B attained within 4 days and no clinically relevant accumulation of the drug following multiple doses of 1-7.5 mg/kg/day. In autopsy tissue, the highest concentrations of the drug were found in the liver and spleen, followed by the kidney, lung, myocardium and brain tissue. Elimination of liposomal amphotericin B, like that of amphotericin B deoxycholate, is poorly understood; its route of metabolism is not known and its excretion has not been studied. The terminal elimination half-life is about 7 hours. No dosage adjustment is required based on age or renal impairment. In several randomized, double-blind trials (n = 73-1095) in adult and/or paediatric patients, liposomal amphotericin B was effective as empirical therapy or as treatment for confirmed invasive fungal infections, including invasive candidiasis, candidaemia, invasive mould infection (mainly aspergillosis), histoplasmosis and cryptococcal meningitis. All agents were administered as an intravenous infusion; the typical dosage for liposomal amphotericin B was 3 mg/kg/day. Treatment was generally given for 1-2 weeks. Participants in trials evaluating empirical therapy had neutropenia and a persistent fever despite antibacterial treatment and had received chemotherapy or undergone haematopoietic stem cell transplantation. As empirical therapy in adult and paediatric patients, liposomal amphotericin B appeared to be as effective as amphotericin B deoxycholate (approximately 50% of patients in each group achieved treatment success) or amphotericin B lipid complex (approximately 40% of liposomal amphotericin B recipients experienced treatment success). Of note, in the first trial, results of the statistical test to determine equivalence between treatments were not reported. In the second trial, efficacy was assessed as an 'other' endpoint. In another trial, caspofungin was shown to be noninferior to liposomal amphotericin B, with approximately one-third of patients in each group experiencing treatment success. Liposomal amphotericin B was significantly more effective than amphotericin B deoxycholate for the treatment of moderate to severe disseminated histoplasmosis in patients with AIDS, with 88% and 64% of patients, respectively, having a successful response. Liposomal amphotericin B was noninferior to amphotericin B deoxycholate for the treatment of cryptococcal meningitis in terms of mycological success. Micafungin therapy was shown to be noninferior to liposomal amphotericin B for the treatment of adult patients with candidaemia or invasive candidiasis. In a substudy in paediatric patients, which was not powered to determine noninferiority, liposomal amphotericin B was as effective as micafungin for the treatment of candidaemia or invasive candidiasis. In this patient population, within each trial, 90% of adult patients and approximately three-quarters of paediatric patients in both treatment groups experienced a successful response. In patients with invasive mould infection (mainly aspergillosis), there was no difference in efficacy between a higher dosage of liposomal amphotericin B (10 mg/kg/day) and the standard dosage (3 mg/kg/day), with 46% and 50% of patients experiencing a favourable overall response. In well designed clinical trials, liposomal amphotericin B was generally at least as well tolerated as other lipid-associated formulations of amphotericin B and better tolerated than amphotericin B deoxycholate in adult and paediatric patients. Compared with other amphotericin B formulations, liposomal amphotericin B treatment was associated with a lower incidence of infusion-related adverse events and nephrotoxicity. A higher than recommended dosage of liposomal amphotericin B (10 mg/kg/day) was associated with an increased incidence of nephrotoxicity compared with the standard dosage (3 mg/kg/day), although the incidence of infusion-related reactions did not differ between treatment groups. In general, liposomal amphotericin B treatment was not as well tolerated as echinocandin therapy in well designed clinical trials. As empirical therapy or for the treatment of confirmed invasive fungal infections in adult patients, liposomal amphotericin B recipients experienced more infusion-related events and nephrotoxicity than caspofungin or micafungin recipients. There was no difference in the incidence of these adverse events between the liposomal amphotericin B and micafungin groups in a study in paediatric patients.

Clinical and laboratory signs as dengue markers during an outbreak in Rio de Janeiro

BACKGROUND

One of the main challenges for clinical research in dengue is the low validity of clinical diagnosis.

OBJECTIVE

To analyze clinical and laboratory data as predicitve factors of dengue diagnosis at Evandro Chagas Clinical Research Institute, Oswaldo Cruz Foundation, during the 2001-2002 dengue outbreak in Rio de Janeiro.

METHODS

Cross sectional study comparing clinical laboratory data collected from the National Information System for Compulsory Notification Diseases (SINAN) in two serologically confirmed groups: dengue D (N = 453) and non-dengue ND (N = 80).

RESULTS

Fever, exanthema, itching, mean platelet count < 150,000, WBC count < 4,000 and absence of vomiting and of abdominal pain help to distinguish D from ND groups. When considered individually, these signs and symptoms enhance diagnostic sensitivity and, when used in combination, improve specificity.

CONCLUSION

A combination of symptoms not necessarily considered indicative of dengue diagnosis could improve surveillance and medical decision-making in simple clinical settings.

Considerations in the approach to invasive fungal infection in patients with haematological malignancies

Invasive infections because of opportunistic yeasts and moulds have contributed significantly to the morbidity and mortality associated with potentially curative treatment for haematological malignancies. Many risk factors have been identified that permit the clinician to predict the likelihood of these infections. The diagnostic process involves maintaining a high index of suspicion based upon an understanding of the clinical circumstances under which invasive fungal infections occur, of the spectrum of fungal syndromes, and of the advantages and limitations of diagnostic testing strategies now available. Treatment strategies may be categorized as prophylactic, pre-emptive, empiric, or directed based upon the circumstances. The therapeutic options have increased in recent years but are not applicable to all clinical circumstances. These considerations are discussed.

Antibiotic Prescribing in Critical Care: Specific Indications

This article outlines recommendations for the treatment of specific infections occurring in the setting of critical care. In the interests of brevity, a limited number of infections are discussed and recommendations are largely confined to empirical therapy. Basic principles of diagnosis and treatment apply in all cases, including appropriate de-escalation when an organism is identified. These aspects of treatment have been dealt with in part one of this article – ‘Antibiotic prescribing in critical care: general principles' published in the winter 2007 edition of JICS.

Influência do tempo e do meio de transporte no isolamento de fungos patogênicos de biópsias de pele

FUNDAMENTOS: Não está definido como o meio de transporte e o intervalo de tempo até o processamento final interferem no isolamento de fungos patogênicos em material obtido de biópsias de pele. OBJETIVOS: Determinar o efeito da inoculação tardia de biópsias de pele, transportadas em diferentes meios líquidos, na taxa de isolamento de fungos patogênicos. MÉTODOS: De 47 pacientes com lesões cutâneas suspeitas de micoses invasivas obtiveram-se 278 biópsias das lesões. Cada biópsia foi transportada em frascos com caldo Sabouraud com cloranfenicol ou solução salina de cloreto de sódio e inoculada em ágar Sabouraud após 48-72 horas (precoce) ou após 72 horas até sete dias (tardio), constituindo-se quatro grupos de estudo. RESULTADOS: As medianas das taxas de isolamento dos quatro grupos de esporotricose foram 100% e de paracoccidioidomicose foram 84% e 50% nos grupos precoces/solução salina ou caldo Sabouraud e 64% e 84% nos grupos tardios/solução salina ou caldo Sabouraud, respectivamente (p=0,88). Baixas taxas de contaminação resultaram em especificidade diagnóstica de 82% para doenças não fúngicas. CONCLUSÕES: Biópsias de pele podem ser transportadas em caldo Sabouraud ou solução salina por períodos de até sete dias, à temperatura ambiente, sem afetar a viabilidade dos fungos.

Diagnosis of invasive aspergillosis by galactomannan antigenemia detection using an enzyme immunoassay

Invasive aspergillosis is a serious and often fatal infection in patients who are neutropenic or have undergone solid organ or stem cell transplantation. Delayed diagnosis and therapy may lead to poor outcomes. Diagnosis may be facilitated by a test for galactomannan antigen detection using an enzyme immunoassay. Other rapid methods for diagnosis include (1-->3)-beta-D: -glucan determination and polymerase chain reaction. The sensitivity and specificity of galactomannan antigenemia testing in serum and bronchoalveolar lavage specimens are high in patients with hematological malignancy, neutropenia, and receipt of stem-cell transplants. False positivity can be seen with concomitant administration of some antibiotics and infection by fungi other than Aspergillus.

Invasive Cryptococcus neoformans infection in an asplenic patient

Individuals who are asplenic or have impaired splenic function are at increased risk of developing life-threatening infections, especially due to encapsulated bacteria. This risk is higher in children, but adults can also develop fulminant infection or "post splenectomy sepsis" (PSS). Cryptococcus neoformans is an encapsulated yeast usually causing infection in immunocompromised patients. In a recent review of cryptococcal infection in HIV-negative patients, splenectomy was reported to be a risk factor for infection in 3% of cases. Detailed case reports are lacking. Here we report a case of disseminated C. neoformans infection in a patient who had a splenectomy performed for warm autoantibody haemolytic anaemia some months before he presented with signs and symptoms of meningitis. This report aims to raise awareness of the possibility of C. neoformans infection in asplenic patients.

A 7-dimethylallyltryptophan synthase from Aspergillus fumigatus: overproduction, purification and biochemical characterization

A putative prenyltransferase gene, Afu3g12930, was identified in the genome sequence of Aspergillus fumigatus. EAL92290, encoded by Afu3g12930, consists of 472 aa, with a molecular mass of about 53 kDa. The coding sequence of Afu3g12930 was cloned in pQE60, and overexpressed in Escherichia coli. The soluble His(6)-fusion protein was purified to apparent homogeneity, and characterized biochemically. The enzyme was found to catalyse the prenylation of Trp at the C-7 position of the indole moiety, in the presence of dimethylallyl diphosphate (DMAPP); therefore, it functions as a 7-dimethylallyltryptophan synthase (7-DMATS). The structure of the enzymic product was elucidated by NMR and MS analysis. K(m) values were 67 microM for DMAPP, and 137 microM for l-Trp. Geranyl diphosphate was not accepted as prenyl donor, while Trp-containing dipeptides were found to be aromatic substrates of 7-DMATS. 7-DMATS did not need divalent metal ions for its enzymic reaction, although Ca(2+) enhanced the reaction velocity slightly. The enzyme is the second dimethylallyltryptophan synthase identified in A. fumigatus. Interestingly, it shares a sequence identity of only 31 % at the amino acid level with another known dimethylallyltryptophan synthase, FgaPT2, from the same fungus; FgaPT2 prenylates l-Trp at the C-4 position of the indole ring. Afu3g12930 belongs to a putative biosynthetic gene cluster consisting of eight genes. Orthologous clusters were also identified in the genome sequences of Neosartorya fischeri and Aspergillus terreus. The putative roles of the genes in the cluster are discussed.

Genomics and the development of new diagnostics and anti-Candida drugs

Pathogenic Candida species remain a significant medical problem despite the availability of antifungal therapies. Two key issues must be addressed to improve the treatment of life-threatening systemic Candida infections. First, advanced diagnostic tools are required to facilitate the early identification of these infections, when therapeutic intervention is more likely to be effective. Second, improved antifungal therapies are needed. These therapies, which might include combinations of antifungals, need to be less toxic to the patient and more potent in killing a broader range of Candida species. Recent advances in unravelling the genomics of these species should facilitate efforts to achieve these goals. We discuss the contribution of genomics to the development of novel antifungals and new diagnostic tools.

Voriconazole : a review of its use in the management of invasive fungal infections

Voriconazole (VFEND), a synthetic second-generation, broad-spectrum triazole derivative of fluconazole, inhibits the cytochrome P450 (CYP)-dependent enzyme 14-alpha-sterol demethylase, thereby disrupting the cell membrane and halting fungal growth. In the US, intravenous and/or oral voriconazole is recommended in adults for the treatment of invasive aspergillosis, candidaemia in non-neutropenic patients, disseminated infections caused by Candida spp., oesophageal candidiasis, and in patients with scedosporiosis and fusariosis who are refractory to or intolerant of other antifungal therapy. In Europe, intravenous and/or oral voriconazole is recommended in adults and paediatric patients of at least 2 years of age for the treatment of invasive aspergillosis, candidaemia in non-neutropenic patients, fluconazole-resistant serious invasive Candida spp. infections, scedosporiosis and fusariosis. In large randomised trials, voriconazole was an effective and generally well tolerated primary treatment for candidiasis and invasive aspergillosis in adults and adolescents. More limited data also support the use of voriconazole for the treatment of invasive fungal infections in children, in those with rare fungal infections, such as Fusarium spp. or Scedosporium spp., and in those refractory to or intolerant of other standard antifungal therapies. The availability of both parenteral and oral formulations and the almost complete absorption of the drug after oral administration provide for ease of use and potential cost savings, and ensure that therapeutic plasma concentrations are maintained when switching from intravenous to oral therapy. On the other hand, the numerous drug interactions associated with voriconazole may limit its usefulness in some patients. Further clinical experience will help to more fully determine the position of voriconazole in relation to other licensed antifungal agents. In the meantime, voriconazole is a valuable emerging option for the treatment of invasive aspergillosis and rare fungal infections, including Fusarium spp. and Scedosporium spp. infections, and provides an alternative option for the treatment of candidiasis, particularly where the causative organism is inherently resistant to other licensed antifungal agents.

Lung mass caused by Phoma exigua

We describe a well documented case of a fatal Phoma exigua lung infection in a patient with acute myeloid leukaemia and diabetes. The infection was histology and culture proven and a PCR assay was developed for detecting P. exigua DNA in deparaffinized lung-biopsy material. Confirmation of rare fungal pathogen infections requires a multidisciplinary approach involving clinical observations, mycology, histopathology and radiology.

A consensus on fungal polymerase chain reaction diagnosis?: a United Kingdom-Ireland evaluation of polymerase chain reaction methods for detection of systemic fungal infections

The limitations of classical diagnostic methods for invasive fungal infections (IFIs) have led to the development of molecular techniques to aid in the detection of IFIs. Despite good published performance, interlaboratory reproduction of these assays is variable, and no consensus has been reached for an optimal method. This publication describes the first multicenter study of polymerase chain reaction methods, for the detection of Aspergillus and Candida species, currently used in the UK and Ireland by distribution and analysis of multiple specimen control panels. All three Candida methods were comparable, achieving a satisfactory level of detection (10 cfu), and the method of preference was dependent on the requirements of the particular laboratory. The results for the five Aspergillus assays were more variable, but two methods (2Asp and 4Asp) were superior (10(1) conidia). Formally, the overall performances of the two Aspergillus assays were comparable (kappa statistic = 0.77). However, on the Roche LightCycler, there was a clear sample-type effect that greatly reduced the detection limit of the 4Asp method when testing whole blood samples. Therefore, the preferred Aspergillus method relied on the amplification platform available to the user. This study represents the initial process to achieve a consensus method for the diagnosis of IFIs.

Invasive fungal infections: a review of epidemiology and management options

Fungi are increasingly recognised as major pathogens in critically ill patients. Candida spp. and Cryptococcus spp. are the yeasts most frequently isolated in clinical practice. The most frequent filamentous fungi (moulds) isolated are Aspergillus spp., but Fusarium spp., Scedosporium spp., Penicillium spp., and Zygomycetes are increasingly seen. Several reasons have been proposed for the increase in invasive fungal infections, including the use of antineoplastic and immunosuppressive agents, broad-spectrum antibiotics, and prosthetic devices and grafts, and more aggressive surgery. Patients with burns, neutropenia, HIV infection and pancreatitis are also predisposed to fungal infection. The epidemiology and clinical features of fungal infections are reviewed, together with antifungal agents currently or soon to be available.

Microscopic, cultural and molecular evidence of disseminated invasive aspergillosis involving the lungs and the gastrointestinal tract

A patient with acute promyelocytic leukaemia developed invasive aspergillosis post chemotherapy during a pancytopenic episode, clinically involving the lungs and the gastrointestinal tract. Dichotomously branched septate fungal hyphae were demonstrated microscopically in stools and sputa. Cultures of the samples yielded Aspergillus flavus, which were identical by RFLP and random amplification of polymorphic DNA analyses and antifungal MICs, proving disseminated disease. To the best of the author's knowledge, this is the first time that boluses of fungal hyphae have been demonstrated microscopically in the stools of a patient with gastrointestinal aspergillosis.

Audit of laboratory mycology services for the management of patients with fungal infections in the northwest of England

BACKGROUND

Fungal infection is increasingly recognised as an important cause of morbidity and mortality, especially in immunocompromised patients. Little information exists on laboratory services available and the methods used by general microbiology laboratories to diagnose these important infections.

AIM

To investigate the services microbiology laboratories in northwest England provide towards the diagnosis and management of superficial and deep fungal infections.

METHODS

A questionnaire was sent to laboratories to get a holistic view of the support given to clinicians looking after patients with fungal infections. The aim was not to investigate details of each laboratory's standard operating procedures. The completed questionnaires, which formed the basis of this report, were returned by all 21 laboratories which were recruited. This study was conducted between March 2004 and September 2004.

RESULTS

Services were provided to District General Hospitals and to six tertiary centres, including eight teaching hospitals by 16 laboratories. Their bed capacity was 250-1300 beds. Total specimens (including bacterial and viral) processed annually were 42 000-500,000 whereas fungal ones were 560-5400.

CONCLUSION

In most microbiology laboratories of northwest England, clinicians were aware of the potential of fungal pathogens to cause infections especially in immunocompromised patients. Additional measures such as prolonged incubation of samples were introduced to improve fungal yield from patients at high risk. It is necessary to train and educate laboratory and medical staff about the role of serology and molecular methods in diagnosis and management of patients with fungal infection.

Investigation of the mechanism of action of 3-(4-bromophenyl)-5-acyloxymethyl-2,5-dihydrofuran-2-one against Candida albicans by flow cytometry

The mechanism of action of the antifungal agent 3-(4-bromophenyl)-5-acyloxymethyl-2,5-dihydrofuran-2-one against Candida albicans was investigated by flow cytometry, using propidium iodide, DiBAC4(3), and FUN-1 as the fluorescent dyes. A related but less active agent, together with amphotericin B and fluconazole, was tested in parallel for comparison of the results. The incrustoporine derivative was found to have a potent fungicidal activity on C. albicans, resulting in damage of cell membrane.

Septic cavernous sinus thrombosis: an unusual and fatal disease

BACKGROUND

Septic cavernous sinus thrombosis (CST) is a rare and fatal disease. Clinical presentations in the early stage are nonspecific, and the sensitivity of cranial axial computed tomography (CT) with thick section is low. This study analyzed the clinical manifestation and neuroimaging findings in patients with septic CST in a medical center in Taiwan.

METHODS

This retrospective case series included nine patients with septic CST who had typical symptoms and clinical course, evidence of infection, and imaging studies which demonstrated cavernous sinus lesion, and who were treated between 1995 and 2003 at National Taiwan University Hospital.

RESULTS

Seven (77.8 %) patients were more than 50 years old. Five (55.6%) had diabetes, and three (33.3%) had hematologic diseases. All cases were associated with paranasal sinusitis. The most frequent initial symptom was headache (66.7%), followed by ophthalmic complaints (diplopia or ophthalmoplegia, 55.6%; blurred vision or blindness, 55.6%), and ptosis (44.4%). Initial cranial images failed to identify CTS in all patients. Subsequent magnetic resonance imaging (MRI) or coronal contrast-enhanced CT (CECT) with thin section confirmed the diagnosis. Fungi were the most common pathogens (55.6%). The inhospital case-fatality rate was high (44.4%).

CONCLUSION

Due to the high case-fatality rate and low yield rate of blood cultures, fungal CST should be suspected in an immunocompromised patient with ophthalmic complaints that progress from one eye to the other. Coronal thin-section CECT may be a useful alternative to MRI as a diagnostic modality for this condition.