Search

Background and Objectives: During a community methicillin-resistant Staphylococcus aureus (MRSA) nasal colonization study, an MRSA strain with vancomycin hetero-resistance (h-VISA) was isolated from a five year-old girl with tetralogy of Fallot without previous exposure to vancomycin. An extended nasal colonization study was performed on all her close relatives., Results: Only the patient and her sister were colonized by an h-VISA MRSA strain (clone USA 700, ST72, t148, agr 1 and SCCmec IVa). Mupirocin decolonisation was effective in the elder sister. A new nasal decolonisation in the younger girl using fusidic acid was also successful. However, after decolonisation both sisters were colonized by a methicillin-susceptible S. aureus (ST30, t012 and agr 3) previously isolated from their mother's nostrils., Conclusion: As S. aureus have a great capacity to spread among people in close contact, knowledge of a patients' colonization status, tracing contacts, and a correct management are critical issues for the successful containment of multiresistant staphylococci., (Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.)

Diagnosis of invasive mycoses is a difficult challenge due to the limitations and low sensitivity of traditional microbiology methods which lead to diagnostic and therapeutic delays. The aim of this review is to summarise the state of the art of the molecular diagnosis of invasive fungal disease and to clarify its current role in the clinical practice. Conventional microbiological methods could be complemented with molecular methods in the rapid and definitive identification of fungal isolates. Biomarkers (β-glucan, galactomannan) are very useful in immunocompromised patients and have been included as probable invasive mycoses by the EORTC/MSG. Nucleic acid detection is currently used as a complementary tool for diagnosis. However, PCR can be very useful in mould invasive mycoses. Finally, the combined detection using biomarkers can improve the diagnosis. However, their applicability in the microbiology laboratory is not so easy and further studies are required for the appropriate evaluation of its clinical usefulness., (Copyright © 2011 Elsevier España, S.L. All rights reserved.)

Introduction: Biofilm production is considered a potential virulence factor of some Candida species. For this reason, an understanding of biofilm behavior of Candida albicans and its closely related species Candida dubliniensis is key to the development of effective preventive measures for invasive and oral candidiasis. The aim of this study was to compare the capacity of biofilm production by blood and oral isolates of C. albicans and C. dubliniensis using polystyrene, flat-bottomed 100-well microtiter plates., Methods: A total of 47 isolates, consisting of 28 C. albicans (16 oral and 12 blood isolates) and 19 C. dubliniensis (11 oral and 8 blood isolates) were compared for their biofilm forming ability under aerobic and static conditions. XTT reduction assay was used to quantify the sessile growth., Results: All tested isolates produced biofilm, measured as XTT metabolic activity. Biofilm formation by C. albicans isolates was statistically significantly higher than biofilm formation by C. dubliniensis isolates at 24h (P=0.03) and 48 h (P=0.0001). There was a higher percentage (41.7%) of high producers of biofilms among C. albicans blood isolates than among oral isolates (31.3%), without statistically significant differences., Conclusions: This capability may allow C. albicans and C. dubliniensis to maintain their oral ecological niches as commensal or pathogenic microorganisms and can be a major virulence factor during invasive candidiasis. However, the differences in biofilm production among isolates should be taken into account when the anti-biofilm activity of antifungal agents or other virulence factors are tested in vitro., (Copyright © 2011 Elsevier España, S.L. All rights reserved.)

Micafungin is a semisynthetic lipopeptide developed from Coleophoma empetri, which blocks the synthesis of β-1,3-D-glucan, an essential component of the fungal wall, though non-competitive inhibition of β-1,3-D-glucan synthetase. Micafungin is a dose-dependent candidacidal agent with excellent in vitro efficacy against most Candida spp. including species resistant to amphotericin B, such as Candida lusitaniae, several azoles, such as C. glabrata or C. krusei, and isolates not susceptible to other echinocandins. Moreover, this drug is active against Candida biofilms. Micafungin is a first-line drug for the treatment of candidemias and invasive candidiasis in adults and children (including neonates). This drug is approved for use in the treatment of invasive candidiasis and Candida esophagitis, as well as in the prophylaxis of Candida infections in hematopoietic stem cell transplant recipients or those at risk of prolonged neutropenia. Micafungin can be used both in the treatment and prevention of candidiasis in neonates, children, adolescents, adults, and the elderly, making it highly useful in patient groups in which the use of other antifungal drugs has not been authorized., (Copyright © 2011 Elsevier España S.L. All rights reserved.)

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., (Copyright © 2010 Elsevier España, S.L. All rights reserved.)

Objectives: Because of its considerable epidemiological relevance, accurate identification of Candida dubliniensis should be routinely performed in clinical microbiology laboratories. In an attempt to facilitate this task, the usefulness of the Bichro-Dubli test (Fumouze Diagnostics, Levallois-Perret, France) was assessed., Methods: Seventy-five collection strains (55 C. dubliniensis and 20 C. albicans) and 135 clinical yeast isolates that grew as green colonies in CHROMagar Candida were studied., Results: Bichro-Dubli was positive in 54 of 55 C. dubliniensis strains (sensitivity 98.2%) and negative in the 20 C. albicans strains (specificity 100%). The test identified 4 C. dubliniensis isolates among the 135 isolates cultured from clinical specimens., Conclusions: The Bichro-Dubli test is easy to perform and allows rapid identification of C. dubliniensis.

Introduction: Two tests for the detection of antibodies to Candida albicans germ tubes in patients with invasive candidiasis were compared: a new commercially available test (Candida albicans IFA IgG) and the indirect immunofluorescence test generally used for this purpose., Methods: With the use of two indirect immunofluorescence tests, retrospective study was done on 172 sera from 51 patients classified into two groups: Group I included 123 serum samples from 32 patients with invasive candidiasis, and Group II, the control, included 49 serum samples from 19 patients with no evidence of Candida infection., Results: In Group I, 84% of patients presented anti-germ tube antibody titers >or= 1:160 by the Candida albicans IFA IgG test and 78.1% of patients were positive by the generally used test. There was a high correlation between the two tests (R2 =0.9512 by patients; R2 = 0.8986 by sera). When a titer value of >or= 1:160 was used as cutoff, the Candida albicans IFA IgG test showed a sensitivity of 84.4% and a specificity of 94.7%, whereas the traditional test showed a sensitivity of 78.1% and a specificity of 100%., Conclusions: The commercially available Candida albicans IFA IgG test is similar to the test generally used for the detection of antibodies to C. albicans germ tubes and provides faster and easier diagnosis of invasive candidiasis in the clinical microbiology laboratory.

Background: Candida albicans infections are frequent in immunocompromised patients and a prompt diagnosis could favor an early and proper antifungal treatment. The rapid identification of clinical yeast isolates facilitate this diagnosis., Methods: The utility of Fluoroplate Candida ready-to-use plates for Candida albicans rapid identification was evaluated with 653 clinical isolates from 23 yeast species, including 307 C. albicans plated onto Fluoroplate Candida agar (Merck, Germany). Rapid identification of C. albicans was based on the hydrolysis of 4-methylumbelliferyl-N-acetyl-beta-D-galactosaminide by the galactosaminidase activity of C. albicans producing white fluorescent colonies under ultraviolet light. Identification on Fluoroplate Candida was confirmed by germ tube, chlamydoconidia formation and API-ATB ID 32C assays., Results: Three hundred and five of 306 isolates showing fluorescent colonies were C. albicans and one was Candida glabrata (false positive). The rest of the isolates showed colonies without fluorescence and with the exception of two false negatives, these isolates were identified as non-C. albicans by other methods., Conclusions: Fluoroplate Candida allows a rapid and excellent identification of C. albicans showing a sensitivity and specificity of 99.3 and 99.7%, respectively.

Background: Candida albicans is the most frequently species isolated in patients with candidiasis. This species may be antigenically divided in serotypes A and B, which have a different pathogenic behavior and antifungal susceptibility pattern., Methods: The antifungal susceptibility of 443 clinical isolates from both serotypes of C. albicans to 5-fluorocytosine (5FC), amphotericin B, nystatin, econazole, miconazole and ketoconazole has been tested by means of the ATB Fungus method., Results: Both serotypes showed a similar in vitro susceptibility to amphotericin B, nystatin, econazole, miconazole and ketoconazole. All the isolates were susceptible to amphotericin B and nystatin. A small number of in vitro resistant isolates were observed to azole compounds. However, serotype B was significantly more resistant than serotype A (p = 0.0001) to 5FC., Conclusions: C. albicans serotype B shows a lower susceptibility than serotype A to 5FC, an antifungal product not marketed in Spain. Serotyping of C. albicans does not offer additional information on antifungal susceptibility of clinical isolates from this species.

The usefulness of a commercial test for mannose detection in the diagnosis of invasive candidosis was evaluated. Serum mannose was observed in 20 of 22 patients with invasive candidal infection, in a concentration greater than or equal to 60 mumol/l. In 68.2% of them, serum mannose concentration was significant (greater than or equal to 60 mumol/l). The specificity of the test was 91.8%. Efficiency, predictive value positive and negative were 77.5, 58.8 and 94.6%, respectively.