Evaluación del Aspergillus lateral flow device para el diagnóstico de aspergilosis invasora, experiencia en un hospital universitario / Evaluation of the lateral flow Aspergillus assay for the diagnosis of invasive aspergillosis, experience in a university hospital

Resumen Introducción: El diagnóstico de aspergilosis invasora (AI) se realiza mediante criterios clínicos y microbiológicos los que incluyen marcadores séricos. Recientemente, el test inmunocromatográfico Aspergillus lateral flow device (LFD), ha sido evaluado como método para diagnóstico de AI. Objetivo: Evaluar el desempeño de este test para el diagnóstico de AI. Material y Método: Estudio transversal en que se evaluaron muestras de suero y lavado bronco-alveolar (LBA) procesadas para galactomanano provenientes de pacientes adultos con sospecha de AI, atendidos en el Hospital Clínico de Red de Salud UCCHRISTUS. Resultados: Se procesó un total de 142 muestras de 98 pacientes, correspondientes a AI probada 5,6%, AI probable 41,5%, AI posible 12,7% y ausencia de AI 40,1%. Al confrontar los resultados con las categorías diagnósticas según criterios EORTC/MSG se obtuvo una sensibilidad y especificidad de LFD para diagnóstico de AI de 70,9 y 53,5% para muestras de suero y 83,3 y 38,5% para muestras de LBA. La concordancia entre galactomanano y LFD fue de 62,4% (54,1-69,9) con un índice Kappa de 0,202 (0,03682-0,3669). Conclusiones: Aspergillus LFD presentó una adecuada sensibilidad; sin embargo, la especificidad fue baja por lo que un resultado positivo requiere ser confirmado.

Background: The incidence of invasive aspergillosis is increasing. Its diagnosis is based on clinical and microbiological criteria which include the determination of serological markers such as galactomannan. Recently, the Aspergillus lateral flow device, an inmunocromatograph assay has been described for its diagnosis. Aim: To evaluate the performance of the lateral flow device for the diagnosis of invasive aspergillosis (IA) in adult patients. Material and Method: In this cross-sectional study, frozen samples that had been previously evaluated for galactomannan from patients classified with proven/probable/possible or no AI according to the EORTC/MSG criteria were selected. Results: A total of 142 samples from 98 patients were processed, corresponding to proven AI 5.6%, probable IA 41.5%, possible IA 12.7% and no-IA 40.1%. The sensitivity and specificity of the Aspergillus lateral flow was 70.9% and 53.5% for serum samples and 83.3% and 38.5% for BAL samples. The concordance between the galactomannan and Aspergillus lateral flow was 62.4% (54.1 - 69.9) with a Kappa index of 0.202 (0.03682 - 0.3669). Conclusions: We observed a good sensitivity but low specificity, a positive result need a confirmatory test.

Letalidad de citocalasina B y otros compuestos aislados del hongo Aspergillus spp. (Trichocomaceae) endófito de Bauhinia guianensis (Fabaceae) / Lethality of cytochalasin B and other compounds isolated from fungus Aspergillus sp. (Trichocomaceae) endophyte of Bauhinia guianensis (Fabaceae)

Los hongos endofíticos son hongos que colonizan los tejidos internos de las plantas; varios compuestos biológicamente activos se han aislado a partir de estos hongos. Existen pocos estudios de compuestos aislados de hongos endófitos de plantas amazónicas. Por lo tanto, este estudio tuvo como objetivo el aislamiento y la identificación estructural de ergosterol (1), peróxido de ergosterol (2), mevalonolactona (3), citocalasina B (4) y citocalasina H (5) a partir de Aspergillus spp. EJC 04, un hongo endofítico de Bauhinia guianensis. La citocalasina B (4) y el derivado diacetato de citocalasina B (4a) mostraron una alta letalidad en el ensayo de Artemia salina. Esta es la primera aparición de citocalasinas en hongos endófitos amazónica de B. guianensis

Endophytic fungi are fungi that colonize internal tissues of plants; several biologically active compounds have been isolated from these fungi. There are few studies of compounds isolated from endophytic fungi of Amazon plants. Thus, this study aimed the isolation and structural identification of ergosterol (1), ergosterol peroxide (2), mevalonolactone (3), cytochalasin B (4) and cytochalasin H (5) from Aspergillus sp. EJC 04, an endophytic fungus from Bauhinia guianensis. The cytochalasin B (4) and the diacetate derivative of cytochalasin B (4a) showed high lethality in the brine shrimp assay. This is the first occurrence of cytochalasins in Amazonian endophytic fungi from B. guianensis

Galactomannan detection from piperacillin-tazobactam brands available in the Brazilian market

Piperacillin-tazobactam is a broad spectrum antimicrobial agent that can cause false-positive results in the commercial Platelia Aspergillus EIA test. So far, no study has been performed in Latin America to evaluate the clinical implication of this finding. Here we studied the potential for galactomannan detection in piperacillin-tazobactam batches commercialized in the Brazilian market. Five batches from distinct laboratories were tested in duplicate in the Platelia Aspergillus EIA according to the manufacturer's instructions. Only one drug showed crossreaction at a cut-off of 0.5. Human serum was spiked with this particular drug aiming to mimic achievable piperacillin-tazobactam concentrations in the serum. Results were all negative for galactomannan detection, even at high drug concentrations. Results from this pilot study suggest that piperacillin-tazobactam might not be a clinically significant cause of false-positive results in the Platelia Aspergillus EIA test in Brazil.

Sclerosing mediastinitis caused by Aspergillus terreus.

A case of Aspergillus terreus causing sclerosing mediastinitis which presented with symptoms of cardiorespiratory compromise and compressive myelopathy is described. The diagnosis was established by culturing and isolating the fungus in pure culture from the tissue and was also confirmed by demonstration of sepcific precipitating antibodies against Aspergillus terreus in patient's serum.

Heterogeneity of immune responses to various Aspergillus species in patients with allergic respiratory diseases.

In the present study, allergenic significance of thirteen species of Aspergillus and their allergenic and antigenic relationship was studied. Of the 3025 ID tests performed with the 13 species of Aspergillus on 289 patients suffering with allergic respiratory diseases, 627 (20.7%) were positive (1+ to 4+), 386 (12.8%) being significantly positive (2+ to 4+) . Of the 64 patients eliciting a positive cutaneous response to at least one species, 42(65.6%) were positive to 5 or less number of species while others showed a broad spectrum of positive skin reactivity to different Aspergillus extracts. In RAST inhibition assays using pooled sera ofpatients sensitive to A. tamarii dose related inhibition was produced by homologous as well as 5 of the 12 heterologous species. Similarly, in A. terreus RAST inhibition was observed with homologous and A. tamarii extracts only. Our results suggested the presence of both species specific as well as shared allergenic components among different Aspergillus species. In TDIEP experiments using rabbit antisera to A. tamarii and A. terreus extracts multiple precipitin bands were observed with the homologous extracts. However, only 1-2 bands were produced by 6 heterologous Aspergillus species in each system. Collectively, these results gave evidence that there is heterogeneity of immune response in the patients with allergic respiratory diseases to different species of Aspergillus and also in rabbits immunized with Aspergillus extracts.

Sensitization to different species of Aspergillus in bakery workers and general atopic population.

Six species of Aspergillus predominant in the bakery environment--Aspergillus flavus, A. fumigatus, A. nidulans, A. ochraceous, A. sydowi and A. versicolor--were studied for their role in causing Type 1 hypersensitivity among bakery workers and atopic patients from the general population (PGP). Antigenic extracts from the above species were prepared for in vivo and in vitro studies. The IEF, SDS-PAGE, skin test, ELISA and immunoblot techniques were performed to detect the biochemical- and clinico-immunological characteristics of these species. Among those tested, the important fungal sensitizers among the bakery workers and patients from the general population were A. sydowi, A. fumigatus, A. nidulans and A. ochraceous. The protein fractions of different species were in the acidic region (pI 3.0-6.5) and in the molecular weight range of 13.0-91.0 kDa. The protein fraction of 44.0 kDA of A. flavus and 20.0 and 70.0 kDa for A. fumigatus showed IgE binding in the sera of bakery workers only. Significantly, raised IgG antibodies to different species were recorded among the bakery workers as compared to the PGP group. The study showed that different species of Aspergillus are of potential allergenic significance in bakery workers and the general atopic population.

Variación anual de la microflora en la ciudad de San Juan y en hogares de pacientes con patología respiratoria IgE dependiente / Annual mycoareological variation in San Juan city, Argentine Republic, and in houses of IgE dependent respiratory pathology patients

El objetivo del estudio fue establecer la variación anual de la microflora en la ciudad de San Juan y en hogares de pacientes con patología respiratoria IgE dependiente. San Juan es una provincia del oeste de la República Argentina, con escasísimas precipitaciones pluviales anuales (menos de 10 mm), con un promedio de humedad relativa ambiente de 46 por ciento (min.: 36 por ciento y máx.: 55 por ciento) y una temperatura promedio de 17,6ºC (min.: 7,8ºC y máx.: 26,5ºC). Para poder conocer el desarrollo de hongos y definir mejor la correlación existente entre ellos y las enfermedades alérgicas respiratorias, estudiamos durante un período anual (julio 1994-junio 1995) la presencia de seis géneros de hongos: Alternaria, Cladosporium, Penicillium, Aspergillus, Mucor y Rhizopus, en el ambiente exterior de la ciudad de San Juan, y en el domicilio de nueve (9) niños con enfermedad respiratoria (rinitis y/o asma), con Prick Test positivo para todos los hongos en estudio. Se controló la reactividad sanguínea de estos pacientes a los mismos géneros de hongos por IgE RAST. La flora micológica fue estudiada por el método gravimétrico, exponiendo mensualmente cápsulas de Petri (diámetro: 10 cm) en medio ambiente externo y en los domicilios (4 cápsulas por domicilio), con medios de cultivo de Sabouraud y Czapek-Dox (Lab. Merck). Los Prick Test se realizaron con antígenos Allergon AB (Lab. Welt), y las IgE RAST (Allerex Labs. Inc - USA). El hongo que se desarrolló con más frecuencia en los domicilios estudiados fue el Penicillium (40,63 por ciento), seguido por Rhizopus (17,24 por ciento), Aspergillus (14,09 por ciento), Mucor (11,28 por ciento), Cladosporium (4,81 por ciento), Alternaria (4,75 por ciento), y otros (7,0 por ciento). Aunque en distinto porcentaje, la distribución de hongos en ambientes externos sigue una curva muy similar a las halladas en los domicilios: Penicillium (17,86 por ciento), Rhizopus (12,76 por ciento), Aspergillus (11,13 por ciento), Mucor (9,97 por ciento), Alternaria (8,12 por ciento), Cladosporium (6,03 por ciento) y otros (1,39 por ciento). La mayor concentración de hongos se alcanzó en octubre para domicilios y en noviembre-diciembre para ambiente exterior. La mejor correlación entre el Prick Test y el RAST se obtuvo para Alternaria y Aspergillus (87 por ciento), seguidos por Cladosporium (75 por ciento), Penicillium (62 por ciento), Rhizopus (50 por ciento), y Mucor (37 por ciento). No encontramos correlación directa entre la respuestas de los pacientes y la concentración de hongos en el período de estudio, confirmando lo esperado de acuerdo con las diferentes potencias alergénicas de cada género

Variación anual de la micoflora en hogares de pacientes asmáticos en la ciudad de Santa fe / Annual variation of the mycoflora in home of asthmatic patients in the Santa Fe city

Mold allergy in frequently involved in the etiopathogenesis of allergy respiratory diseases and it is important for us to determine the fungal classes that most frequently cohabit with men in our region, and under which condition of temperature and humidity they mostly develop. Mycological flora was studied bimonthly in 1989, in 8 homes from Santa Fe City, by exposing three dishes (90 mm) for 20 min. in bathrooms, kitchens and bedrooms. Afterwards, the dishes were incubated for 10 days at 28ºC. Taxonomic identification was made by microscopy of the mature sporulating colonies. Alternaria was the fungal class most frequently found (64 por ciento), followed by Cladospotium (11,4 por ciento), Aspergillus (9,2 por ciento), Curvularia (7 por ciento), Penicillium (4 por ciento), Fusarium (1,2 por ciento) and others (3,2 por ciento). Concerning the rooms, altemaria and Cladosporium were mostly found in kitchens, un like the classes Aspergillus, penicillium and Curvularia that were mostly found in bedrooms. Considering all the colonies as a whole, the totals of each room were: for kitchens 50 por ciento: for bedrooms 28,5 por ciento: and for bathrooms, 21,5 por ciento. The greatest concentration of total colonies was found to those month varied from 70 to 75 por ciento, and the average temperature was stated between 16 and 22ºC. According to the medium values for temperature and humidity in Santa Fe City, spring in the most suitable season for in home molds to develop, being the kitchen the room where a greater number of colonies was found

Sensitization to Aspergillus antigens in perennial rhinitis.

This study was conducted to determine the frequency of sensitization to Aspergillus antigens in 27 patients with perennial rhinitis. Immediate cutaneous reactivity was observed in 7 (26%) patients. In 3 of these 7 patients, hypersensitivity was restricted to Aspergillus antigens alone. One patient had an isolated late cutaneous reaction. Hypersensitivity was observed most commonly with A. flavus. Serum precipitins to A. flavus were detected in one patient. It is possible that sensitization to Aspergillus antigens may play an important role in the causation of perennial rhinitis and could also increase the risk of developing other Aspergillus associated hypersensitivity respiratory disorders subsequently.

Prevalence of antibodies to aspergilli in bronchial asthmatics.

Sputum and bleed samples were analysed from 330 cases of bronchial asthmatics and 50 normal persons without features of bronchial asthma. The prevalence of aspergilli and antibodies to different Aspergillus species were detected using cultural methods and serological technique like agar gel double diffusion (DD), counter-immuno-electrophoresis (CIEP) and enzyme-linked immunosorbent assay (ELISA). Out of total 6.06% yielded Aspergillus species in sputum specimens repeatedly. Precipitins against Aspergillus species were detected in 7.88% of cases by DD and CIEP. ELISA test showed 20% of cases to be having antibodies to A. fumigatus. Allergic broncho-pulmonary aspergillosis can be detected in the early course of the disease in bronchial asthmatics using highly sensitive technique like ELISA.