[Show abstract][Hide abstract] ABSTRACT: A total of 216 colonies of Malassezia pachydermatis from 28 cases of fungal otitis or dermatitis in pets were genotyped by M13 fingerprinting and tested for antifungal susceptibility. A huge genetic diversity was found (157 M13 types in total), with all animals having a polyclonal pattern of infection (5.4 ± 1.5 genotypes/sample). Furthermore, analysis of molecular variance (AMOVA) revealed that most genetic diversity (44%) was found at the within sample level. In contrast, variability in antifungal susceptibility among isolates from the same sample was less important, with different M13 types displaying in most cases identical or very similar MIC results. Most isolates displayed high in vitro susceptibility to amphotericin B, terbinafine and all azoles tested except fluconazole, for which MIC values were always ≥4 μg/ml and a 26.9% of isolates displayed values ≥32 μg/ml. We conclude that although characterization of multiple yeast isolates results in a considerable increase in laboratory workload and expenses, it may help to get a better understanding of the epidemiology of M. pachydermatis in a given patient population.
Medical mycology: official publication of the International Society for Human and Animal Mycology 09/2015; DOI:10.1093/mmy/myv070 · 2.34 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Most current guidelines do not recommend systematic screening with echocardiography in patients with candidemia, as Candida infective endocarditis (CIE) is considered an uncommon disease. During the study period, we recommended echocardiography systematically to all candidemic patients that did not have contraindications and accepted to participate in the study. We intended to assess the incidence of unrecognized CIE in adult patients with candidemia. Our institution is a tertiary teaching hospital in which we follow all patients with candidemia. From January 2007 to October 2012, echocardiography was systematically recommended to suitable candidates. We recorded 263 cases of candidemia in adult patients. Echocardiography was not performed in 76 of these patients for the following reasons: patients had died when blood cultures became positive (17), patients were critically or terminally ill (38), or the patient or physician refused the procedure (21). The remaining 187 patients constitute the basis of this report. CIE was diagnosed in 11 cases (4.2 % of the whole candidemic population and 5.9 % of the population with echocardiographic study). The results of transthoracic echocardiography (TTE) suggested infective endocarditis (IE) in 5/172 patients (2.9 %), and the result of transesophageal echocardiography (TEE) was positive in 10/87 (11.5 %). Among 11 confirmed cases of CIE, the disease was clinically unsuspected in three patients. At least 4.2 % of all candidemic patients have CIE. CIE is frequently clinically unsuspected and echocardiography is required to demonstrate a high proportion of cases.
European Journal of Clinical Microbiology 05/2015; 34(8). DOI:10.1007/s10096-015-2384-z · 2.67 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We report the first isolation of a voriconazole-resistant Aspergillus fumigatus strain harbouring the azole resistance mechanism TR46/Y121F/T289A, recovered from an azole-naive patient in Spain with chronic obstructive pulmonary disease. This new finding in Spain suggests the spread of this resistance mechanism and reinforces the need for antifungal susceptibility surveillance.
[Show abstract][Hide abstract] ABSTRACT: We assessed the in vitro activity of micafungin against preformed Candida biofilms by measuring the concentration of drug causing the most fungal damage and inhibition of regrowth. We studied 37
biofilm-producing Candida spp. strains from blood cultures. We showed that micafungin was active against planktonic and sessile forms of Candida albicans strains and moderately active against Candida parapsilosis sessile cells. Concentrations of micafungin above 2 μg/ml were sufficiently high to inactivate regrowth of Candida sessile cells.
[Show abstract][Hide abstract] ABSTRACT: Many bloodstream infections (BSI) in patients with central venous catheters (CVC) are not catheter-related (CR). Assessment
of catheter involvement without catheter withdrawal has not been studied in candidemia. We assessed the value of conservative
techniques to evaluate catheters as the origin of candidemia in patients with CVC in a prospective cohort study (superficial
Gram stain and culture, Kite technique (Gram stain and culture of the first 1 cm blood drawn from the CVC), proportion of
positive blood cultures (PPBCs), differential time to positivity (DTP), and minimal time to positivity (MTP)). All catheters
were cultured at withdrawal. From June 2008 to January 2012, 22 cases fulfilled the inclusion criteria. CR-candidemia (CRC)
was confirmed in 10. Validity values for predicting CRC were: superficial Gram stain (S, 30%; Sp, 81.83%; PPV, 60%; NPV, 56.3%;
Ac, 57.1%), superficial cultures (S, 40%; Sp, 75%; PPV, 57.1%; NPV, 60%; Ac, 59.1%), Kite Gram stain (S, 33.3%; Sp, 66.7%;
PPV, 50%; NPV, 50%; Ac, 50%), Kite culture (S, 80%; Sp, 66.7%; PPV, 66.7%; NPV, 80%; Ac, 72.7%), PPBC (S, 50%; Sp, 41.7%;
PPV, 41.7%; NPV, 50.0%; Ac, 45.5%), DTP (S, 100%; Sp, 33.3%; PPV, 55.6%; NPV, 100%; Ac, 63.6%), and MTTP (S, 70%; Sp, 58.3%;
PPV, 58.3%; NPV, 70%; Ac, 63.6%). While combinations of two tests improved sensitivity and NPV, more than two tests did not
improve validity values. Classic tests to assess CR-BSI caused by bacteria cannot be reliably used to diagnose CRC. Combinations
of tests could be useful, but more and larger studies are required.
Medical Mycology 06/2014; 52(5):491-497. DOI:10.1093/mmy/myu013 · 2.34 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Catheter-related candidemia (CRC) is typically a biofilm related disease, but it is mostly unknown if the production of biofilm
is a feature exclusively shown by Candida spp. isolates causing CRC. We performed an in vitro biofilm assay using Candida isolates obtained from the blood of patients with candidemia. We demonstrated that biofilm production was not a good predictor
of catheter-related candidemia. Also, we demonstrated that there was no difference in the mortality of candidemia patients
infected by biofilm-forming isolates and those in which the infection is caused by nonbiofilm-forming species.
Medical mycology: official publication of the International Society for Human and Animal Mycology 04/2014; 52(4). DOI:10.1093/mmy/myt031 · 2.34 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Although ECVs (epidemiologic cutoff values) have been established for Candida spp. and the triazoles, they are based on MIC data from a single laboratory. We have established ECVs for eight Candida species and fluconazole, posaconazole and voriconazole based on wild-type (WT) MIC distributions for isolates of C. albicans (11, 241), C. glabrata (7, 538), C. parapsilosis (6, 023), C. tropicalis (3, 748), C. krusei (1, 073), C. lusitaniae (574), C. guilliermondii (373), and C. dubliniensis (162). The 24-h CLSI broth microdilution MICs were collated from multiple laboratories (Canada, Brazil, Europe, Mexico, Peru, and the United States). ECVs for distributions originating from ≥6 laboratories, which included ≥95% of the modelled WT population (fluconazole, posaconazole, and voriconazole, respectively) were: 0.5, 0.06 and 0.03 μg/ml for C. albicans; 0.5, 0.25, and 0.03 μg/ml for C. dubliniensis; 8, 1 and 0.25 μg/ml for C. glabrata; 8, 0.5 and 0.12 μg/ml for C. guilliermondii; 32, 0.5 and 0.25 μg/ml for C. krusei; 1, 0.06 and 0.06 μg/ml for C. lusitaniae; 1, 0.25 and 0.03 μg/ml for C. parapsilosis; and 1, 0.12 and 0.06 μg/ml for C. tropicalis. The low number of MICs (<100) for other less prevalent species (C. famata, C. kefyr, C. orthopsilosis, C. rugosa) precluded ECV definition, but their MIC distributions are documented. Evaluation of our ECVs for some species/agent combinations using published individual MICs for 136 isolates (harbouring mutations in or up-regulation of ERG11, MDR1, CDR1 and CDR2) and 64 WT isolates indicated that our ECVs may be useful in distinguishing WT from non-WT isolates.