Fungicidal monoclonal antibody C7 interferes with iron acquisition in Candida albicans.

We have developed a monoclonal antibody (MAb), C7, that reacts with the Als3p and enolase present in the Candida albicans cell wall and exerts three anti-Candida activities: candidacidal activity and inhibition of both adhesion and filamentation. To investigate the mode of action of MAb C7 on fungal viability, we examined changes in the genome-wide gene expression profile of C. albicans grown in the presence of a subinhibitory concentration of MAb C7 (12.5 µg/ml) by using microarrays. A total of 49 genes were found to be differentially expressed upon treatment with MAb C7. Of these, 28 were found to be upregulated and 21 were found to be downregulated. The categories of upregulated genes with the largest number of variations were those involved in iron uptake or related to iron homeostasis (42.86%), while the energy-related group accounted for 38.10% of the downregulated genes (8/21). Results were validated by real-time PCR. Since these effects resembled those found under iron-limited conditions, the activity of MAb C7 on C. albicans mutants with deletions in key genes implicated in the three iron acquisition systems described in this yeast was also assessed. Only mutants lacking the TPK1 gene and, to a lesser extent, the TPK2 gene were less sensitive to the candidacidal effect of MAb C7. FeCl(3) or hemin at concentrations of ≥ 7.8 µM reversed the candidacidal effect of MAb C7 on C. albicans in a concentration-dependent manner. The results presented in this study provide evidence that the candidacidal effect of MAb C7 is related to the blockage of the reductive iron uptake pathway of C. albicans.

Clinical factors associated with a Candida albicans Germ Tube Antibody positive test in Intensive Care Unit patients.

BACKGROUND: Poor outcomes of invasive candidiasis (IC) are associated with the difficulty in establishing the microbiological diagnosis at an early stage. New scores and laboratory tests have been developed in order to make an early therapeutic intervention in an attempt to reduce the high mortality associated with invasive fungal infections. Candida albicans IFA IgG has been recently commercialized for germ tube antibody detection (CAGTA). This test provides a rapid and simple diagnosis of IC (84.4% sensitivity and 94.7% specificity). The aim of this study is to identify the patients who could be benefited by the use of CAGTA test in critical care setting. METHODS: A prospective, cohort, observational multicentre study was carried out in six medical/surgical Intensive care units (ICU) of tertiary-care Spanish hospitals. Candida albicans Germ Tube Antibody test was performed twice a week if predetermined risk factors were present, and serologically demonstrated candidiasis was considered if the testing serum dilution was ≥ 1:160 in at least one sample and no other microbiological evidence of invasive candidiasis was found. RESULTS: Fifty-three critically ill non-neutropenic patients (37.7% post surgery) were included. Twenty-two patients (41.5%) had CAGTA-positive results, none of them with positive blood culture for Candida. Neither corrected colonization index nor antifungal treatment had influence on CAGTA results. This finding could corroborate that the CAGTA may be an important biomarker to distinguish between colonization and infection in these patients. The presence of acute renal failure at the beginning of the study was more frequent in CAGTA-negative patients. Previous surgery was statistically more frequent in CAGTA-positive patients. CONCLUSIONS: This study identified previous surgery as the principal clinical factor associated with CAGTA-positive results and emphasises the utility of this promising technique, which was not influenced by high Candida colonization or antifungal treatment. Our results suggest that detection of CAGTA may be important for the diagnosis of invasive candidiasis in surgical patients admitted in ICU.

[Spanish Society of Clinical Microbiology and Infectious Diseases (SEIMC) guidelines for the diagnosis of invasive fungal infections. 2010 update]. / Recomendaciones sobre el diagnóstico de la enfermedad fúngica invasora de la Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica (SEIMC). Actualización 2010.

These guidelines are an update of recommendations for the diagnosis of invasive fungal infections by the Spanish Society of Clinical Microbiology and Infectious Diseases (SEIMC) published in 2004 (Enferm Infecc Microbiol Clin. 2004, 22:32-9). In this updated version of the guidelines, a comprehensive review of the most recent diagnostic innovations and levels of evidence to recommend those diagnostic procedures are included. We first analyse conventional diagnostic methods, microscopic examination and culture, underlining their limitations which have led to the development of alternative methods, such as fungal antigen and DNA quantification. Those alternative methods of diagnosis are analysed by fungal infection. We also briefly review the methods for molecular identification of fungal species and recommendations for carrying out susceptibility tests for antifungal drugs, including reference procedures, commercial techniques and their indications.

Prevalence of Candida species in necrotic pulp with chronic periapical processes.

The aim of this study was to identify species of the genus Candida in mucosa of oral cavity and in single-rooted teeth with pulp necrosis with chronic endodontic periapical processes, with radiographic images 2+/-4 mm and without clinical symptomatology, in immunocompetent patients. The study included 82 immunocompetent patients of both sexes aged 18-70 years with a clinical dental diagnosis of septic pulp necrosis. Samples were taken from root canals with sterile # 25 paper points and from oral mucosa with a sterile swab. Seven different Candida species were identified (C. albicans, C. dubliniensis, C. guilliermondii, C. krusei, C. parapsilopsis, C. tropicalis and C. glabrata). All of them were present in oral mucosa, while two of them (C. parapsilopsis and C. glabrata) were not identified in the periapical zone of necrotic canals. Considering all the samples isolated from oral mucosa, there was a significantly greater frequency of C. albicans than there was in the periapical zone of necrotic canals.

Paradoxical growth of Candida dubliniensis does not preclude in vivo response to echinocandin therapy.

Candida dubliniensis commonly shows paradoxical or trailing growth effects in vitro in the presence of echinocandins. We tested the in vitro activities of anidulafungin, caspofungin, and micafungin against clinical isolates of C. dubliniensis and evaluated the efficacy of these drugs in two murine models of systemic infection. The three echinocandins were similarly effective in the treatment of experimental disseminated infections with C. dubliniensis strains showing or not showing abnormal growth in vitro.

Bone microbial contamination influences autogenous grafting in sinus augmentation.

BACKGROUND: The oral occurrence of putative microbial pathogens in humans has been documented in health and disease. The presence of periodontopathogens in patients with a history of periodontal disease may have a negative impact on bone regeneration. This investigation was conducted to confirm the presence of periodontal pathogens in bone particles harvested intraorally for maxillary sinus augmentation and to assess the clinical and radiographic outcomes 6 to 12 months after bone augmentation. METHODS: Culture and polymerase chain reaction (PCR)-based identification were performed by paper-point sampling of intraorally harvested bone particles in a group of 12 maintenance patients undergoing maxillary sinus augmentation. Radiographs were taken to assess and compare bone healing and volume gain at baseline and at 6 to 12 months after augmentation. RESULTS: The presence of periodontal pathogens (Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans [previously Actinobacillus actinomycetemcomitans], Prevotella intermedia, Tannerella forsythia [previously T. forsythensis], Fusobacterium nucleatum, Parvimonas micra [previously Peptostreptococcus micros or Micromonas micros], Campylobacter rectus, enteric Gram-negative rods, and Dialister pneumosintes) was identified in 10 of 12 patients (83%) by culture, PCR, or both and was associated with greater bone volume loss at 6 months postaugmentation. The PCR-positive triad, P. gingivalis, A. actinomycetemcomitans, and P. intermedia, was associated with pronounced volume loss of the grafted sinus at 6 months. CONCLUSIONS: To the best of our knowledge, this is the first study to confirm osseous microbial contamination with major periodontopathogens in individuals undergoing maxillary sinus augmentation with a history of periodontitis. The effect on the grafting outcome translated into bone volume loss in the grafted sinus 6 months postaugmentation. Specific microbial contamination may have an impact on osteogenesis in osseous regeneration.

Monoclonal antibody-mediated inhibition of adhesion of Candida albicans and Candida dubliniensis to human epithelial cells.

The aim of this study was to assess the role of whole saliva, four saliva-derived preparations, and six monoclonal antibodies (mAbs), directed against components of the cell wall of Candida albicans, on the adhesion of C. albicans and Candida dubliniensis to human epithelial cells (HEC). C. albicans serotype A NCPF 3153 and C. albicans serotype B ATCC 90028 showed higher adhesion to HEC than C. dubliniensis NCPF 3949. Pooled whole saliva was more efficient than salivary secretory immunoglobulin A, partially purified by chromatography, at inhibiting the adhesion of C. albicans serotype A NCPF 3153 to HEC. Monoclonal antibodies C7, 14-8, and 26G7 were the most potent inhibitors of adhesion. Our results show that mAbs can mimic the inhibition of adhesion of C. albicans to HEC that is mediated by human saliva.

[Usefulness of biological markers in the diagnosis of invasive candidiasis]. / Utilidad de los marcadores biológicos en el diagnóstico de la candidiasis invasora.

BACKGROUND: The laboratory diagnosis of invasive candidiasis is based on the demonstration of tissue invasion by Candida, the culture of the fungus in specimens from sterile body sites and the detection of a number of biomarkers including some antibodies, mannan, beta-1,3-D-glucan and Candida DNA. AIMS: Description and evaluation of results obtained in published studies on the usefulness of biomarkers in the diagnosis of invasive candidiasis. METHODS: A search was performed in the PubMed/Medline database from the National Library of Medicine since January 2000 on the usefulness of biomarkers in the diagnosis of invasive candidiasis. Key words used included candidiasis, Candida, diagnosis, biomarkers, antigen, antibodies, DNA, mannan, and beta-1,3-D-glucan. RESULTS: Forty one papers dealing with the use of biomarkers in the diagnosis of invasive candidiasis were selected and evaluated, paying special attention to the sensitivity and specificity obtained with the tests used. CONCLUSIONS: Important advances are being reached in the use of biomarkers for the diagnosis of invasive candidiasis, and some of them are being used to start a preemptive therapy strategy.

Use of recombinant antigens for the diagnosis of invasive candidiasis.

Invasive candidiasis is a frequent and often fatal complication in immunocompromised and critically ill patients. Unfortunately, the diagnosis of invasive candidiasis remains difficult due to the lack of specific clinical symptoms and a definitive diagnostic method. The detection of antibodies against different Candida antigens may help in the diagnosis. However, the methods traditionally used for the detection of antibodies have been based on crude antigenic fungal extracts, which usually show low-reproducibility and cross-reactivity problems. The development of molecular biology techniques has allowed the production of recombinant antigens which may help to solve these problems. In this review we will discuss the usefulness of recombinant antigens in the diagnosis of invasive candidiasis.

[The fungal cell wall and the mechanism of action of anidulafungin]. / La pared celular de los hongos y el mecanismo de acción de la anidulafungina.

The fungal cell wall is a structure with a high plasticity that protects the cell from different types of environmental stresses including changes in osmotic pressure. In addition to that, the cell wall allows the fungal cell to interact with its environment, since some of its proteins are adhesins and receptors. Some of its components are highly immunogenic. The structure of the fungal cell wall is unique to the fungi, and it is composed of glucan, chitin and glycoproteins. Since humans lack the components present in the cell walls of fungi, this structure is an excellent target for the development of antifungal drugs. Anidulafungin, like the rest of echinocandins acts on beta-1,3-D-glucan synthase inhibiting the formation of beta-1,3-D-glucan and causing, depending on the type of fungus, a fungicidal or either a fungistatic effect.

Isolation of Aspergillus lentulus in Spain from a critically ill patient with chronic obstructive pulmonary disease.

Aspergillus lentulus was first described in the year 2005, and since it cannot be phenotypically distinguished from Aspergillus fumigatus, it is conceivable that earlier descriptions (before 2005) could be attributed to this new species. Currently invasive infections caused by A. lentulus are rare and very few cases have been previously published in neutropenic patients, all of them with fatal outcome. Here we report a critically ill non neutropenic patient with chronic obstructive pulmonary disease (COPD) who was admitted to the medical intensive care unit with an exacerbation of COPD and who had been treated with long term corticosteroids. A. fumigatus was cultured from two bronchial aspirates and in a third bronchial aspirate both A. lentulus and A. fumigatus were isolated. On two consecutive days detection of galactomannan in serum was negative whilst detection of (1-3) beta-D glucan was positive (> 518 pg/ml). Minimal inhibitory concentrations (MIC) for itraconazole, voriconazole, caspofungin and amphotericin B were high for this strain of A. lentulus. Given the high MIC values of A. lentulus to available antifungals, the accurate identification of this new species is warranted. To our knowledge, this is the first report of the isolation of A. lentulus in a non-neutropenic critically ill patient, although we note that since it was isolated only once from respiratory specimens, its implication as an etiologic agent of infection for this patient remains to be established.

Diagnosis of invasive candidiasis by enzyme-linked immunosorbent assay using the N-terminal fragment of Candida albicans hyphal wall protein 1.

BACKGROUND: The diagnosis of invasive candidiasis is difficult because there are no specific clinical manifestations of the disease and colonization and infection are difficult to distinguish. In the last decade, much effort has been made to develop reliable tests for rapid diagnosis of invasive candidiasis, but none of them have found widespread clinical use. RESULTS: Antibodies against a recombinant N-terminal fragment of the Candida albicans germ tube-specific antigen hyphal wall protein 1 (Hwp1) generated in Escherichia coli were detected by both immunoblotting and ELISA tests in a group of 36 hematological or Intensive Care Unit patients with invasive candidiasis and in a group of 45 control patients at high risk for the mycosis who did not have clinical or microbiological data to document invasive candidiasis. Results were compared with an immunofluorescence test to detect antibodies to C. albicans germ tubes (CAGT). The sensitivity, specificity, positive and negative predictive values of a diagnostic test based on the detection of antibodies against the N-terminal fragment of Hwp1 by immunoblotting were 27.8 %, 95.6 %, 83.3 % and 62.3 %, respectively. Detection of antibodies to the N-terminal fragment of Hwp1 by ELISA increased the sensitivity (88.9 %) and the negative predictive value (90.2 %) but slightly decreased the specificity (82.6 %) and positive predictive values (80 %). The kinetics of antibody response to the N-terminal fragment of Hwp1 by ELISA was very similar to that observed by detecting antibodies to CAGT. CONCLUSION: An ELISA test to detect antibodies against a recombinant N-terminal fragment of the C. albicans germ tube cell wall antigen Hwp1 allows the diagnosis of invasive candidiasis with similar results to those obtained by detecting antibodies to CAGT but without the need of treating the sera to adsorb the antibodies against the cell wall surface of the blastospore.

Cross-reactivity between Candida albicans and oral squamous cell carcinoma revealed by monoclonal antibody C7.

BACKGROUND: Monoclonal antibodies developed against Candida albicans cell wall mannoproteins cross-react with human ovarian cancer. These antibodies reacted with the nuclear pore complex protein Nup88, which is overexpressed in a number of human tumors. The aim of this study was to investigate if Nup88 revealed by monoclonal antibody C7 is overexpressed in early oral squamous cell carcinoma (EOSCC) and if this expression has a prognostic value. PATIENTS AND METHODS: A monoclonal antibody against a C. albicans cell wall manoprotein was used to investigate the expression of Nup88 in 34 EOSCC (T1/T2 N0M0). RESULTS: Mab C7 was mostly located in the cytoplasm and extracts from EOSCC showed specific bands of 47-40 and 70 kDa that were not observed in normal oral mucosa. The highest levels of Mab C7 reactivity were observed in 13 (38.2%) tumors. The Kaplan-Meier test showed the median survival time to be shorter in those EOSCC cases with the highest Mab C7 reactivity. CONCLUSION: The monoclonal antibody C7 raised against a C. albicans cell wall mannoprotein cross-reacts with an antigen from oral squamous cell carcinoma whose expression is associated with poor prognosis. The overexpression of this antigen is associated with a poor prognosis in early squamous cell carcinoma.

[Present and future of voriconazole in the treatment of invasive mycoses: the inseparable binomial diagnosis-treatment]. / Presente y futuro de voriconazol en el tratamiento de las micosis invasoras: el inseparable binomio diagnóstico-tratamiento.

Two milestones have characterized the last decades in Medical Mycology: the continuous increase in incidence of invasive mycoses and the discovery of new antifungal drugs that have allowed the successful treatment of these severe infections. This monography presents the most relevant studies on the present situation of invasive mycoses, its diagnosis and treatment, as well as data confirming the important role of voriconazole in their treatment.

[Advances and limitations in the early diagnosis of invasive yeast infections]. / Avances y limitaciones del diagnóstico precoz de las infecciones invasoras causadas por levaduras.

In the last years, the main advances in the serological diagnosis of mycoses caused by yeasts have occurred in the area of antibody and (1-3)-beta-D-glucan detection. Commercialization of the Candida albicans IFA IgG test and detection of antibodies against recombinant antigens Hwp1 and enolase are the most important contributions to the first area. Detection of (1-3)-beta-D-glucan confirms its usefulness as a good marker for the diagnosis of invasive candidiasis. The most recent studies suggest that combination of two tests to detect antígen, antibodies, (1-3)-beta-D-glucan and DNA will be needed to optimize the diagnosis of systemic yeast infections.

[Thirty years of the "Asociación Española de Micología"]. / La Asociación Española de Micología cumple 30 años.

Since the foundation of the "Asociación Española de Micología" thirty years ago, we have consolidated the Spanish mycological community and also witnessed remarkable changes, not only in the Spanish society but in the scientific community as a whole. As it usually happens to human beings, during this time the "Asociación Española de Micología" has matured transforming itself into a solid scientific society. However, the "Asociación Española de Micología" will have to continue its transformation to adapt to new changes. This article shows the most relevant aspects in the history of the "Asociación Española de Micología" as well as new challenges that the society might face in the future.

[Early diagnosis of invasive fungal infections caused by Aspergillus and other emerging mycelial fungi]. / Estado actual del diagnóstico precoz de las infecciones invasoras causadas por Aspergillus y otros hongos filamentosos emergentes.

The usefulness of surrogate markers in the diagnosis of invasive fungal infections caused by Aspergillus and other emerging mycelial fungi is based on the ability of surrogate markers to detect the infection caused by different species of mycelial fungi. Conventional microbiological methods for diagnosis of fungal disease are slow and insensitive. Antigen based assays or measurement of (1-3)-beta-D-glucan in blood have been developed and validated in clinical laboratories. We review these diagnostic contemporary tools, their clinical application and impact.

False positive galactomannan results in adult hematological patients treated with piperacillin-tazobactam.

In this prospective study including 78 adult patients with haematological malignancy (90 episodes) we performed galactomannan (GM) (Platelia Aspergillus) screening twice weekly for the diagnosis of invasive aspergillosis. There were five proven and four probable invasive aspergillosis cases. The sensitivity, specificity and positive and negative predictive values were 100, 88, 47 and 100%, respectively. There were eight patients with false positive GM (10.2%). In six patients the false GM reactivity was due to the administration of piperacillin-tazobactam (P-T). A significant association was found between false positive GM (= or > 0.5) and the administration of P-T (p < 0.01). Two other patients with no invasive aspergillosis (2.5%) and false GM reactivity had graft versus host disease (GVHD) and one of them had also mucositis grade IV. The kinetic patterns of false positive GM due to P-T is discussed.

A phase I clinical and pharmacokinetic study of paclitaxel and docetaxel given in combination in patients with solid tumours.

The aim of this study was to determine the safety and feasibility profile of paclitaxel (PTX) and docetaxel (DTX) in combination and the pharmacokinetic and pharmacodynamic interaction between these two drugs in two different alternated sequences of administration. The starting dose was PTX (100 mg/m(2)) as a 3-h IV infusion followed by DTX (50 mg/m(2)) as 1-h IV infusion or the alternative sequence in every other patient. The sequence was alternated in the second course in each patient treated. Cycle duration was 21 days. Twenty patients received 103 cycles of treatment through three dose levels. Febrile neutropenia and grade 4 neutropenia lasting longer than 7 days were dose-limiting and defined the toxic dose of DTX (50 mg/m(2)) and PTX (135 mg/m(2)) in patients with prior treatment and the recommended dose in patients without prior treatment. Non-hematological toxicities included asthenia, neuropathy, arthralgia/myalgia and stomatitis. Pharmacokinetics of DTX were significantly affected by the sequence. Nadir ANC was more profound when DTX was administered first (P=0.022). There were one complete response and six partial responses, giving an overall response rate of 35%. DTX (50 mg/m(2)) followed by PTX (135 mg/m(2)) can be administered safely and it is an active regimen. The pharmacokinetics of PTX are not influenced by DTX but DTX pharmacokinetics depend on the sequence of administration, which influences its haematological toxicity profile.

Evaluation of Bichro-Dubli Fumouze to distinguish Candida dubliniensis from Candida albicans.

We have evaluated the ability of the Bichro-Dubli Fumouze (Fumouze Diagnostics, Levallois-Perret, France) latex agglutination test to identify colonies of Candida dubliniensis grown on different media. The test was positive for 103 of 106 isolates of C. dubliniensis and negative for Candida albicans and other Candida species studied. The sensitivity and specificity of the test were 97.1% and 100%, respectively. The test is very rapid, simple, and reliable giving the same results independently of whether the colonies are grown previously on Sabouraud dextrose agar, CHROMagar Candida medium, Candida ID2 medium, or CHROMagar-Pal's medium.