Guillermo Ezpeleta

Variación de la epidemiología de las fungemias y de la sensibilidad al fluconazol de los aislamientos de hemocultivos en los últimos 10 años en España: resultados del estudio FUNGEMYCA

BACKGROUND Recent epidemiological surveillance studies have reported an increase in fungaemia caused by non-Candida albicans species, as well as a decrease in fluconazole susceptibility. OBJECTIVES To evaluate changes in the epidemiology of fungaemia in Spain comparing data from a new surveillance epidemiological study conducted in 2009 with a previous study carried out from 1997 to 1999 (Pemán J, et al. Eur J Clin Microbiol Infect Dis. 2005). METHODS From January 2009 to February 2010, 44 Spanish hospitals participated in a prospective multicentre fungaemia surveillance study to ascertain whether there have been changes in the epidemiology and fluconazole susceptibility. Susceptibility was determined by the colorimetric method Sensititre Yeast One. Demographic and clinical data and the first isolate of each episode were gathered. RESULTS A total of 1,377 isolates from 1,357 fungaemia episodes were collected, 46.7% from patients older than 64years and 8.6% from children less than 1 year old. C. albicans (44.7%), Candida parapsilosis (29.1%), Candida glabrata (11.5%), Candida tropicalis (8.2%), and Candida krusei (1.9%) were the most frequent species isolated. Distribution varied with the geographical area. C. albicans incidence has increased significantly in the last 10years in Cataluña (39.1 vs. 54.7%, P=0.03) and decreased in the Valencian Community (49.1 vs. 34.6%, P=0.002) and Extremadura (58.3 vs. 20%, P=0.01). Susceptibility to fluconazole was similar for all geographical areas, although resistance in C. albicans was ten times greater for patients aged more than 64years. The overall rate of fluconazole resistance (MIC > 32 mg/L) has decreased with respect to that obtained 10years ago (3.7 vs. 2.5%) mainly in C. albicans (3 vs. 1.6%). CONCLUSIONS In the last ten years, species distribution and fluconazole susceptibility have not significantly changed, although a lower rate of fluconazole resistance has been observed. Species distribution varies with hospital, hospitalization Unit and geographical area.

OriginalVariación de la epidemiología de las fungemias y de la sensibilidad al fluconazol de los aislamientos de hemocultivos en los últimos 10 años en España: resultados del estudio FUNGEMYCAChanges in the epidemiology of fungaemia and fluconazole susceptibility of blood isolates during the last 10 years in Spain: results from the FUNGEMYCA study

BACKGROUND Recent epidemiological surveillance studies have reported an increase in fungaemia caused by non-Candida albicans species, as well as a decrease in fluconazole susceptibility. OBJECTIVES To evaluate changes in the epidemiology of fungaemia in Spain comparing data from a new surveillance epidemiological study conducted in 2009 with a previous study carried out from 1997 to 1999 (Pemán J, et al. Eur J Clin Microbiol Infect Dis. 2005). METHODS From January 2009 to February 2010, 44 Spanish hospitals participated in a prospective multicentre fungaemia surveillance study to ascertain whether there have been changes in the epidemiology and fluconazole susceptibility. Susceptibility was determined by the colorimetric method Sensititre Yeast One. Demographic and clinical data and the first isolate of each episode were gathered. RESULTS A total of 1,377 isolates from 1,357 fungaemia episodes were collected, 46.7% from patients older than 64years and 8.6% from children less than 1 year old. C. albicans (44.7%), Candida parapsilosis (29.1%), Candida glabrata (11.5%), Candida tropicalis (8.2%), and Candida krusei (1.9%) were the most frequent species isolated. Distribution varied with the geographical area. C. albicans incidence has increased significantly in the last 10years in Cataluña (39.1 vs. 54.7%, P=0.03) and decreased in the Valencian Community (49.1 vs. 34.6%, P=0.002) and Extremadura (58.3 vs. 20%, P=0.01). Susceptibility to fluconazole was similar for all geographical areas, although resistance in C. albicans was ten times greater for patients aged more than 64years. The overall rate of fluconazole resistance (MIC > 32 mg/L) has decreased with respect to that obtained 10years ago (3.7 vs. 2.5%) mainly in C. albicans (3 vs. 1.6%). CONCLUSIONS In the last ten years, species distribution and fluconazole susceptibility have not significantly changed, although a lower rate of fluconazole resistance has been observed. Species distribution varies with hospital, hospitalization Unit and geographical area.

Enfermedad fúngica invasora: ¿Diagnóstico micológico convencional o molecular?

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.

Incidencia etaria y geográfica y patrón de sensibilidad a los antifúngicos de las especies de Candida causantes de candidemia en la población pediátrica española

INTRODUCTION There are few epidemiological studies on candidaemia in the paediatric population in Spain. We sought to determine the epidemiology of candidaemia in these patients. METHODS Prospective, observational and multicentre study in 44 Spanish hospitals. All candidaemia episodes in paediatric patients from 0 to 15 years old between January 2009 and February 2010 were studied. RESULTS There were 197 episodes and 200 species were isolated. The most frequent species was Candida parapsilosis sensu stricto (43%), followed by C. albicans (36%), C. tropicalis (6%), C. orthopsilosis, and C. glabrata (4%) respectively. C. albicans was the most prevalent in newborns, and C. parapsilosis was most frequent in the other age groups. As regards the regions of Spain, C. albicans was most prevalent in patients from Catalonia, the Balearic Islands and Canary Islands, and C. parapsilosis in patients from Andalusia, Castilla-León, Galicia, Valencia, and Madrid. The rate of resistance to fluconazole was 1.5% (4.1% with the new species-specific Clinical and Laboratory Standards Institute [CLSI] criteria). Fluconazole resistance was lower in neonates than the other age groups. The Neonatal Wards were the areas with most episodes (31.5%). In the multivariate analysis, the variables associated independently with candidaemia due to C. albicans were: catheter (OR: 5.967; 95% CI: 1.614-22.057; P=.007) and prematurity (OR: 2.229; 95% CI: 1.141- 4.631; P=.020). CONCLUSIONS The epidemiology of paediatric candidaemia varies between Spanish regions, but, globally, C. parapsilosis and C. albicans, are respectively, the first and second most frequently isolated species, and they show resistance rates to fluconazole of less than 5%.

Validation of the PCR-dHPLC method for rapid identification of Candida glabrata phylogenetically related species in different biological matrices.

Since two new species phylogenetically related to Candida glabrata with slightly different phenotypes and antifungal susceptibility profiles have been described, it seems to be necessary from clinical point of view, to develop a rapid and accurate identification system in order to distinguish between these three fungal species. We studied the performance of denaturing high performance liquid chromatography (dHPLC) as a faster (less than 7 min) and alternative novel technique for simultaneous analysis of Candida species in different biological matrices. The analyses show the good low limit of detection (LLOD) in all biological matrices studied (5.16-9.56 ngμL(-1), 4.14-4.70 ng μL(-1) and 3.99-4.66 ng μL(-1) for Candida bracarensis, Candida nivariensis and C. glabrata, respectively). 180 Candida isolates were analyzed in order to demonstrate the method suitability for screening analysis to identify C. glabrata and its cryptic species (C. bracarensis and C. nivariensis) in clinical routine.

State of the Art in the Laboratory Methods for the Diagnosis of Invasive Fungal Diseases

Invasive fungal diseases (IFDs) are serious complications in oncohematological and surgical patients. Most IFDs are caused by Candida but other emergent fungi are changing the disease spectrum. The absence of specific symptoms complicates diagnosis. Recovery of fungi from blood and deep specimens remains an insensitive diagnosis, leading to delayed treatment and high mortality. Biomarkers, such as 1,3-β- d -glucan (BG), galactomannan (GM), glucuronoxylomannan (GXM) and mannan, anti-Candida antibodies, or fungal DNA can be useful diagnostic tools. BG is a panfungal marker that can be present early in the blood and other biological fluids of patients suffering from IFD. GM may be detected in the course of invasive aspergillosis and be positive prior to clinical and radiological suspicions of infection. GXM is essential in the diagnosis of cryptococcal meningitis. Mannan and anti-Candida antibody detection is helpful in the diagnosis of invasive candidiasis. DNA detection is a promising diagnostic tool under validation, not yet ready to be recommended for clinical use.

Detection and characterization of surface microbial contamination in emergency ambulances

A cross-sectional study was performed in 10 emergency basic life support ambulances operating in Bilbao, Spain, to assess surface bacterial contamination. Presence of clinically relevant bacterial contamination suggests that disinfection of the studied basic life support ambulances was not optimal and represents a potential risk of infection for the patients transferred in them. It is critical to implement existing infection control and prevention protocols to resolve this issue.

A possible role for fumagillin in cellular damage during host infection by Aspergillus fumigatus

ABSTRACT Virulence mechanisms of the pathogenic fungus Aspergillus fumigatus are multifactorial and depend on the immune state of the host, but little is known about the fungal mechanism that develops during the process of lung invasion. In this study, microarray technology was combined with a histopathology evaluation of infected lungs so that the invasion strategy followed by the fungus could be described. To achieve this, an intranasal mice infection was performed to extract daily fungal samples from the infected lungs over four days post-infection. The pathological study revealed a heavy fungal progression throughout the lung, reaching the blood vessels on the third day after exposure and causing tissue necrosis. One percent of the fungal genome followed a differential expression pattern during this process. Strikingly, most of the genes of the intertwined fumagillin/pseurotin biosynthetic gene cluster were upregulated as were genes encoding lytic enzymes such as lipases, proteases (DppIV, DppV, Asp f 1 or Asp f 5) and chitinase (chiB1) as well as three genes related with pyomelanin biosynthesis process. Furthermore, we demonstrate that fumagillin is produced in an in vitro pneumocyte cell line infection model and that loss of fumagillin synthesis reduces epithelial cell damage. These results suggest that fumagillin contributes to tissue damage during invasive aspergillosis. Therefore, it is probable that A. fumigatus progresses through the lungs via the production of the mycotoxin fumagillin combined with the secretion of lytic enzymes that allow fungal growth, angioinvasion and the disruption of the lung parenchymal structure.

Design and validation of a multiplex PCR protocol for microsatellite typing of Candida parapsilosis sensu stricto isolates

BackgroundAnalysis of polymorphic microsatellite markers (STR) is a helpful genotyping technique to differentiate Candida parapsilosis sensu stricto isolates. The aim of this study is to develop and perform an initial validation of an alternative protocol for the reliable and accurate microsatellite genotyping of C. parapsilosis sensu stricto isolates using high-throughput multiplex PCR. To achieve this, the results obtained using the new protocol were compared to the ones obtained using a previously described reference method. To that end, diagnostic accuracy, informativeness and discrimination parameters were estimated.ResultsOur results showed good concordance between both methods (Kappa index: 0.920), leading to a high sensitivity (1; CI(95%) (0.991–1)) and specificity (1; CI(95%) (0.772–1)) after the validation of the new protocol. Moreover, the electropherograms profiles obtained with the new PCR scheme showed a high signal to noise ratio (SNR).ConclusionsThe new multiplex protocol is valuable for the differentiation of C. parapsilosis sensu stricto, with direct clinical applications. Besides, the new protocol represents a shortening the hands-on time, reducing the sample manipulation (dismissing the possibility of cross-contamination), maintaining the quality of the results (when compared to the ones obtained with the reference method), and helping to the standardization and simplification of the genotyping scheme.