RESUMEN
INTRODUCTION: Identification of yeasts is based on morphological, biochemical and nutritional characteristics, and using molecular methods. Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry, a new method for the identification of microorganisms, has demonstrated to be very useful. The aim of this study is to evaluate this new method in the identification of yeasts. METHODS: A total of 600 strains of yeasts isolated from clinical specimens belonging to 9 genera and 43 species were tested. Identification was made by sequencing of the ITS regions of ribosomal DNA, assimilation of carbon compounds (ID 32C), and mass spectrometry on a Microflex spectrometer (Bruker Daltonics GmbH, Germany). RESULTS: A total of 569 strains (94.8%) were identified to species level by ID 32C, and 580 (96.7%) by MALDI-TOF. Concordance between both methods was observed for 553 strains (92.2%), with 100% in clinically relevant species: C. albicans, C. glabrata, C. parapsilosis, C. tropicalis, and almost 100% in C. krusei. MALDI-TOF identified species requiring molecular methods: Candida dubliniensis, C. nivariensis, C. metapsilosis and C. orthopsilosis. Some irregularities were observed in the identification of arthroconidia yeast and basidiomycetes. CONCLUSION: MALDI-TOF is a rapid, effective and economic method, which enables the identification of most clinically important yeasts and the differentiation of closely related species. It would be desirable to include more species in its database to expand its performance.
Asunto(s)
Técnicas de Tipificación Micológica/métodos , Micosis/microbiología , Levaduras/aislamiento & purificación , Candida/clasificación , Candida/aislamiento & purificación , Isótopos de Carbono/metabolismo , ADN de Hongos/análisis , ADN Espaciador Ribosómico , Humanos , Reproducibilidad de los Resultados , Especificidad de la Especie , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Levaduras/clasificación , Levaduras/metabolismoRESUMEN
In the absence of clinical breakpoints (CBP), epidemiological cutoff values (ECVs) are useful to separate wild-type (WT) isolates (without mechanisms of resistance) from non-WT isolates (those that can harbor some resistance mechanisms), which is the goal of susceptibility tests. Sensititre YeastOne (SYO) is a widely used method to determine susceptibility of Candida spp. to antifungal agents. The CLSI CBP have been established, but not for the SYO method. The ECVs for four azoles, obtained using MIC distributions determined by the SYO method, were calculated via five methods (three statistical methods and based on the MIC50 and modal MIC). Respectively, the median ECVs (in mg/liter) of the five methods for fluconazole, itraconazole, posaconazole, and voriconazole (in parentheses: the percentage of isolates inhibited by MICs equal to or less than the ECVs; the number of isolates tested) were as follows: 2 (94.4%; 944), 0.5 (96.7%; 942), 0.25 (97.6%; 673), and 0.06 (96.7%; 849) for Candida albicans; 4 (86.1%; 642), 0.5 (99.4%; 642), 0.12 (93.9%; 392), and 0.06 (86.9%; 559) for C. parapsilosis; 8 (94.9%; 175), 1 (93.7%; 175), 2 (93.6%; 125), and 0.25 (90.4%; 167) for C. tropicalis; 128 (98.6%; 212), 4 (95.8%; 212), 4 (96.0%; 173), and 2 (98.5; 205) for C. glabrata; 256 (100%; 53), 1 (98.1%; 53), 1 (100%; 33), and 1 (97.9%; 48) for C. krusei; 4 (89.2%; 93), 0.5 (100%; 93), 0.25 (100%; 33), and 0.06 (87.7%; 73) for C. orthopsilosis. All methods included ≥94% of isolates and yielded similar ECVs (within 1 dilution). These ECVs would be suitable for monitoring emergence of isolates with reduced susceptibility by using the SYO method.
Asunto(s)
Antifúngicos/farmacología , Azoles/farmacología , Candida/efectos de los fármacos , Candidiasis/microbiología , Candida/aislamiento & purificación , Humanos , Pruebas de Sensibilidad MicrobianaRESUMEN
BACKGROUND: Healthcare-associated (HCA) bloodstream infections (BSI) have been associated with worse outcomes, in terms of higher frequencies of antibiotic-resistant microorganisms and inappropriate therapy than strict community-acquired (CA) BSI. Recent changes in the epidemiology of community (CO)-BSI and treatment protocols may have modified this association. The objective of this study was to analyse the etiology, therapy and outcomes for CA and HCA BSI in our area. METHODS: A prospective multicentre cohort including all CO-BSI episodes in adult patients was performed over a 3-month period in 2006-2007. Outcome variables were mortality and inappropriate empirical therapy. Adjusted analyses were performed by logistic regression. RESULTS: 341 episodes of CO-BSI were included in the study. Acquisition was HCA in 56% (192 episodes) of them. Inappropriate empirical therapy was administered in 16.7% (57 episodes). All-cause mortality was 16.4% (56 patients) at day 14 and 20% (71 patients) at day 30. After controlling for age, Charlson index, source, etiology, presentation with severe sepsis or shock and inappropriate empirical treatment, acquisition type was not associated with an increase in 14-day or 30-day mortality. Only an stratified analysis of 14th-day mortality for Gram negatives BSI showed a statically significant difference (7% in CA vs 17% in HCA, p = 0,05). Factors independently related to inadequate empirical treatment in the community were: catheter source, cancer, and previous antimicrobial use; no association with HCA acquisition was found. CONCLUSION: HCA acquisition in our cohort was not a predictor for either inappropriate empirical treatment or increased mortality. These results might reflect recent changes in therapeutic protocols and epidemiological changes in community pathogens. Further studies should focus on recognising CA BSI due to resistant organisms facilitating an early and adequate treatment in patients with CA resistant BSI.
Asunto(s)
Antibacterianos/uso terapéutico , Bacteriemia/tratamiento farmacológico , Infecciones Comunitarias Adquiridas/tratamiento farmacológico , Infección Hospitalaria/tratamiento farmacológico , Adulto , Análisis de Varianza , Farmacorresistencia Bacteriana , Femenino , Humanos , Modelos Logísticos , Masculino , Estudios Prospectivos , Curva ROC , Factores de Riesgo , Resultado del TratamientoRESUMEN
Data on fungemia epidemiology and antifungal susceptibility of isolates from children are scarce, leading frequently to pediatric empirical treatment based on available adult data. The present study was designed to update the epidemiological, mycological, and in vitro susceptibility data on fungal isolates from children with fungemia in Spain. All fungemia episodes were identified prospectively by blood culture over 13 months at 30 hospitals. Tests of susceptibility to amphotericin B, flucytosine, fluconazole, itraconazole, posaconazole, voriconazole, anidulafungin, caspofungin, and micafungin were performed at participant institutions by a microdilution colorimetric method. New species-specific clinical breakpoints for fluconazole, voriconazole, and echinocandins were also applied. A total of 203 episodes of fungemia in 200 children were identified. A higher proportion of fungal isolates was from general wards than intensive care units (ICU). Candida parapsilosis (46.8%), Candida albicans (36.5%), Candida tropicalis (5.9%), Candida glabrata (3.9%), and Candida guilliermondii (2.5%) were the leading species. C. parapsilosis was the predominant species except in neonates. C. albicans was the most frequent in neonatal ICU settings (51.9%). Intravascular catheter (79.3%), surgery (35%), prematurity (30%), and neutropenia (11%) were the most frequent predisposing factors. Most Candida isolates (95.1%) were susceptible to all antifungals. When the new species-specific clinical breakpoints were applied, all C. parapsilosis isolates were susceptible to echinocandins except one, which was micafungin resistant. This is the largest published series of fungemia episodes in the pediatric setting. C. parapsilosis is the most prevalent species in Spain, followed by C. albicans and C. tropicalis. Resistance to azole and echinocandin agents is extremely rare among Candida species. The fluconazole resistance rate in Spain has decreased in the last 10 years.
Asunto(s)
Antifúngicos/farmacología , Farmacorresistencia Fúngica , Fungemia/epidemiología , Fungemia/microbiología , Hongos/efectos de los fármacos , Adolescente , Niño , Preescolar , Femenino , Hongos/aislamiento & purificación , Humanos , Lactante , Recién Nacido , Masculino , Pruebas de Sensibilidad Microbiana , Prevalencia , Estudios Prospectivos , España/epidemiologíaRESUMEN
Candida lipolytica has rarely been reported as a human pathogen. We observed two cases of fungemia caused by C. lipolytica, one of them in a 12-year-old child with cystic pancreatic fibrosis in advanced phase and another in a 86-year-old woman who presented vesical neoformation with peritoneal fibrosis, bilateral hydronephrosis and recurrent urinary tract infections. After antifungal treatment and catheter removal, the fungemia appeared to be finished and blood cultures were negative.
Asunto(s)
Candidiasis , Fungemia/microbiología , Anciano de 80 o más Años , Niño , Femenino , Humanos , MasculinoRESUMEN
We report a case of fungemia caused by Kodamaea (Pichia) ohmeri associated with surgery in a patient with a history of diabetes and chronic renal failure. Kodamaea ohmeri is a yeast rarely involved in human infections. Since the first report of a case of fungemia in 1998, only thirteen cases of K. ohmeri infection have been so far described in the medical literature.
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Adrenalectomía , Carcinoma de Células Renales/cirugía , Fungemia/etiología , Neoplasias Renales/cirugía , Nefrectomía , Peritonitis/etiología , Complicaciones Posoperatorias/microbiología , Saccharomycetales/aislamiento & purificación , Anciano de 80 o más Años , Carcinoma de Células Renales/complicaciones , Diabetes Mellitus Tipo 2/complicaciones , Resultado Fatal , Femenino , Fungemia/microbiología , Humanos , Huésped Inmunocomprometido , Fallo Renal Crónico/complicaciones , Neoplasias Renales/complicaciones , Peritonitis/microbiologíaRESUMEN
Erythrovirus B19 has been associated with an expanding range of clinical disorders since its identification as the etiological agent of erythema infectiosum, or fifth disease of childhood: acute arthropathy, dermatologic manifestations, chronic anemia in immunocompromised patients, and transient aplastic crisis in individuals with underlying chronic hemolytic disorders. Furthermore, exposure to and infection by B19 virus can lead to serious complications during pregnancy, which may result in fetal anemia, spontaneous abortion, and hydrops fetalis. Consequently, the B19 immune status of pregnant women should be routinely determined. Because many immunocompromised patients with chronic anemia will respond positively to intravenous immunoglobulin therapy, laboratory confirmation of B19 infection is required. Since Erythrovirus B19 cannot be routinely grown in vitro, diagnostic methods for detecting the presence of B19 by molecular techniques or by investigating the specific immune response should be considered in clinical microbiology laboratories.
Asunto(s)
Parvovirus B19 Humano , Humanos , Infecciones por Parvoviridae/complicaciones , Infecciones por Parvoviridae/diagnóstico , Infecciones por Parvoviridae/terapiaRESUMEN
BACKGROUND: Trichosporonosis is an opportunistic infection caused by the genus Trichosporon. The majority of cases of invasive trichosporonosis occurs in immunocompromised individuals. CASE REPORT: We describe a case of disseminated infection by Trichosporon asahii in a hematology patient. A 52-year-old man diagnosed with acute lymphoblastic leukemia developed a febrile episode during the third cycle of the induction chemotherapy. The blood cultures were positive after 24h incubation, showing elongated structures compatible with fungal elements in the Gram stain. The identification of the fungus as Trichosporon asahii was carried out by the assimilation of compounds of carbon and the amplification and sequencing of the D1/D2 domain and the internal transcribed spacer of the ribosomal DNA. The fungus was also isolated from the pustular lesions that the patient had in the chest. After treatment with amphotericin B, the patient progressed satisfactorily. CONCLUSIONS: Trichosporon asahii is an emergent pathogen in immunosupressed patients and its presence should not be considered as colonization, as there is risk of invasive infection.
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Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Fungemia/microbiología , Infecciones Oportunistas/microbiología , Leucemia-Linfoma Linfoblástico de Células Precursoras/complicaciones , Trichosporon/aislamiento & purificación , Tricosporonosis/etiología , Anfotericina B/uso terapéutico , Antifúngicos/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , ADN de Hongos/análisis , ADN de Hongos/genética , ADN Espaciador Ribosómico/análisis , ADN Espaciador Ribosómico/genética , Dermatomicosis/tratamiento farmacológico , Dermatomicosis/etiología , Dermatomicosis/microbiología , Fungemia/tratamiento farmacológico , Fungemia/etiología , Humanos , Huésped Inmunocomprometido , Masculino , Persona de Mediana Edad , Técnicas de Tipificación Micológica , Infecciones Oportunistas/tratamiento farmacológico , Infecciones Oportunistas/etiología , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , ARN de Hongos/análisis , ARN de Hongos/genética , ARN Ribosómico/análisis , ARN Ribosómico/genética , Tricosporonosis/tratamiento farmacológicoRESUMEN
BACKGROUND: Studies on the susceptability of Cryptococcus species to antifungal agents are scarce. METHOD: We investigate the susceptibility of 54 clinical and environmental strains from six different species using the Sensititre and the NCCLS methods. RESULTS: Environmental strains were less susceptible than clinical strains. We found MICs >= 64 mg/l for fluconazole, MICs >= 1 mg/l for itraconazole and MICs >= 32 mg/l for 5-fluorocytosine in C. albidus, C. neoformans and C. uniguttulatus. CONCLUSIONS: These findings point at the importance of determining the antifungal susceptibility of Cryptococcus species.
Asunto(s)
Antifúngicos/uso terapéutico , Criptococosis/tratamiento farmacológico , Criptococosis/genética , Fluconazol/uso terapéutico , Colorimetría , Criptococosis/microbiología , Predisposición Genética a la Enfermedad , HumanosRESUMEN
Late-onset sepsis is very frequent among preterm infants and cases due to Gram negative pathogens have elevated morbidity and mortality. Pantoea agglomerans is a Gram negative organism which has been rarely reported causing disease in humans. We present a case of P. agglomerans late-onset fulminant sepsis in a preterm newborn at a neonatal intensive care unit. Up to date none P. agglomerans sepsis has been reported among this population in our country.
Asunto(s)
Enfermedades en Gemelos/microbiología , Infecciones por Enterobacteriaceae/microbiología , Pantoea/patogenicidad , Sepsis/microbiología , Resultado Fatal , Femenino , Humanos , Recién Nacido , Unidades de Cuidado Intensivo NeonatalAsunto(s)
Infección Hospitalaria/microbiología , Control de Infecciones/normas , Indicadores de Calidad de la Atención de Salud/estadística & datos numéricos , Infecciones por Acinetobacter/microbiología , Acinetobacter baumannii/aislamiento & purificación , Antibacterianos/uso terapéutico , Infección Hospitalaria/prevención & control , Farmacorresistencia Bacteriana Múltiple , Enterobacteriaceae/enzimología , Enterobacteriaceae/aislamiento & purificación , Infecciones por Enterobacteriaceae/microbiología , Humanos , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Infecciones Estafilocócicas/microbiología , Resistencia betalactámica , beta-Lactamasas/biosíntesisRESUMEN
La sepsis tardía es especialmente frecuente en los recién nacidos pretérmino, y los bacilos gramnegativos son responsables de los casos más graves con una elevada mortalidad asociada. Pantoea agglomerans es un bacilo gramnegativo que pocas veces se ha descrito como patógeno en el ser humano, menos aún en el recién nacido. Se presenta el caso clínico de un recién nacido pretérmino que sufrió una sepsis fulminante por Pantoea agglomerans en una unidad de cuidados intensivos neonatales. Hasta la fecha no se ha descrito ningún caso de sepsis por P. agglomerans en esta población en España.
Late-onset sepsis is very frequent among preterm infants and cases due to Gram negative pathogens have elevated morbidity and mortality. Pantoea agglomerans is a Gram negative organism which has been rarely reported causing disease in humans. We present a case of P. agglomerans late-onset fulminant sepsis in a preterm newborn at a neonatal intensive care unit. Up to date none P. agglomerans sepsis has been reported among this population in our country.