Diagnóstico micológico por técnicas no convencionales en el siglo XXI / Mycological diagnosis by non-conventional techniques in the 21st century

Introducción: En la actualidad las infecciones fúngicas representan un problema para la salud humana. Las infecciones causadas por especies patógenas de hongos registran un incremento constante y se ubican entre el cuarto y décimo lugar como causa de muerte, particularmente en las unidades de cuidado intensivo. Un diagnóstico adecuado y precoz impacta directamente en la morbilidad y mortalidad asociadas a estas. Objetivo: Describir las principales técnicas de diagnóstico no convencional de las enfermedades fúngicas más frecuentes, en especial las relacionadas con el diagnóstico serológico y molecular. Métodos: Se realizó una revisión de la literatura científica sobre el tema, publicada entre 2000 y 2019. Se revisaron un total de 63 trabajos. Como motores de búsqueda se emplearon Google y Google Scholar. Se revisaron las bases de datos Medline, PubMed, Science Direct, BUCea y SciELO. Análisis y síntesis de la información: Las técnicas serológicas se emplean en el diagnóstico de las micosis invasivas o sistémicas por ser fáciles, rápidas y confiables. La detección de anticuerpos tiene utilidad limitada en el diagnóstico de las micosis invasivas debido a que la respuesta puede estar retrasada, reducida o no existir en pacientes inmunocomprometidos. La detección de componentes no antigénicos liberados por los hongos durante la infección y la secuenciación de ácidos nucleicos fúngicos son otras opciones para el diagnóstico de las micosis. Conclusiones: El desarrollo biotecnológico aporta nuevas herramientas que incrementan las oportunidades de identificación de las micosis. En la actualidad se disponen de métodos basados tanto en la detección de marcadores inmunológicos como de elementos moleculares específicos. La eficacia de las herramientas no convencionales para el diagnóstico depende de la correcta combinación de estas(AU)

Introduction: Fungal infections are a current human health problem. Infections caused by pathogenic fungal species constantly increase in number, and are ranked between the fourth and tenth leading causes of death, particularly in intensive care units. Early accurate diagnosis has a direct impact on the morbidity and mortality of fungal infections. Objective: Describe the main non-conventional diagnostic techniques for the most common fungal diseases, especially those related to serological and molecular diagnosis. Methods: A review was conducted of the scientific literature about the topic published between the years 2000 and 2019. A total 63 publications were reviewed. The search engines used were Google and Google Scholar. The databases Medline, PubMed, Science Direct, BUCea and SciELO were reviewed. Data analysis and synthesis: Serological techniques are used for the diagnosis of invasive or systemic mycoses because they are easy, fast and reliable. The detection of antibodies has a limited usefulness in invasive mycosis diagnosis, for the response may be delayed, reduced or inexistent in immunocompromised patients. Detection of non-antigenic components released by fungi during infection and sequencing of fungal nucleic acids are other mycosis diagnosis options. Conclusions: Biotechnological development contributes new tools increasing mycosis identification opportunities. Methods are currently available which are based on detection of immunological markers and specific molecular elements. The efficacy of non-conventional diagnostic tools depends on their appropriate combination(AU)

Antimicrobial Resistance in Bacteria Isolated from Foods in Cuba.

INTRODUCTION Antimicrobial drug resistance constitutes a health risk of increasing concern worldwide. One of the most common av-enues for the acquisition of clinically-relevant antimicrobial resistance can be traced back to the food supply, where resistance is acquired through the ingestion of antimicrobial resistant microorganisms pres-ent in food. Antimicrobial resistance constitutes a health risk, leading to production losses and negative consequences for livelihood and food safety. OBJECTIVE Determine whether resistant bacteria are present in foods in Cuba. METHODS A descriptive observational study was conducted in theMicrobiology Laboratory of Cuba's National Institute of Hygiene, Epi-demiology and Microbiology from September 2004 through Decem-ber 2018. Researchers analyzed 1178 bacterial isolates from food samples. The isolates were identifi ed as Escherichia coli, Salmonella, Vibrio cholerae and coagulase-positive Staphylococcus. The antimi-crobial susceptibility study was performed using the Bauer-Kirby disk diffusion method, following procedures outlined by the Clinical and Laboratory Standards Institute. The data were analyzed using WHO-NET version 5.6. RESULTS Of the total isolates, 62.1% were resistant to at least one antibiotic. Within each group, >50% of isolates showed some type of resistance. E. coli and V. cholerae exceeded 50% resistance to tetracycline and ampicillin, respectively. Staphylococcus showed the highest resistance to penicillin, and Salmonella to tetracycline, nali-dixic acid and ampicillin. The highest percentages of non-susceptible microorganisms were identifi ed in meats and meat products. CONCLUSIONS These results serve as an alert to the dangers of acquiring antibiotic-resistant bacteria from food and demonstrate the need to establish a surveillance system and institute measures bacte-rial control in food products.KEYWORDS Microbial drug resistance, bacteria, food, foodborne disease, Cuba.

Chronic Pulmonary Aspergillosis in Patients with Underlying Respiratory Disorders in Cuba-A Pilot Study.

Chronic pulmonary aspergillosis (CPA) is a fungal infection with high mortality and morbidity rates. This disease is caused by several Aspergillus species and affects patients with an underlying respiratory condition. This pilot study aims to recognize CPA among patients with different respiratory diseases. Twenty-one out of 47 patients were classified as CPA based on the examination of clinical signs and symptoms, radiological findings, mycological culture of respiratory samples and analysis of Aspergillus IgG antibodies. There was a close association between high levels of Aspergillus IgG antibodies and the presence of cavities. Although Aspergillus flavus was the predominant species among clinical isolates, the number of isolates was small to reach conclusions on the prevalence of this species as main cause of CPA in Cuba. From the eleven evaluable patients for the treatment with itraconazole (Lozartil®), nine improved their health status while two did not show any recovery. This drug is included in the therapy schemes for aspergillosis in Cuba.

The status of cryptococcosis in Latin America.

Cryptococcosis is a life-threatening fungal infection caused by the encapsulated yeasts Cryptococcus neoformans and C. gattii, acquired from the environment. In Latin America, as occurring worldwide, C. neoformans causes more than 90% of the cases of cryptococcosis, affecting predominantly patients with HIV, while C. gattii generally affects otherwise healthy individuals. In this region, cryptococcal meningitis is the most common presentation, with amphotericin B and fluconazole being the antifungal drugs of choice. Avian droppings are the predominant environmental reservoir of C. neoformans, while C. gattii is associated with several arboreal species. Importantly, C. gattii has a high prevalence in Latin America and has been proposed to be the likely origin of some C. gattii populations in North America. Thus, in the recent years, significant progress has been made with the study of the basic biology and laboratory identification of cryptococcal strains, in understanding their ecology, population genetics, host-pathogen interactions, and the clinical epidemiology of this important mycosis in Latin America.

Aportes del Laboratorio de Micología del Instituto de Medicina Tropical Pedro Kourí al desarrollo de la especialidad en Cuba / Contributions of the Mycology Laboratory at Pedro Kouri Tropical Medicine Institute to the development of the specialty in Cuba

En el marco del 80 aniversario del Instituto de Medicina Tropical Pedro Kourí, se exponen en apretada síntesis, las actividades más relevantes en el campo del diagnóstico, la investigación y la docencia desarrolladas hasta el momento por el Laboratorio de Micología de la referida institución. A 38 años de su creación, este sigue siendo uno de los pocos lugares en Cuba que se desempeña en este campo y que se reconoce por los logros científico-técnicos alcanzados. Sin lugar a duda, estos responden básicamente al cuadro de salud nacional, sin descuidar el entorno regional y mundial. Todos los resultados que se exponen, se encuentran sustentados por más de 100 publicaciones y otras obras científicas, lo que avala la calidad y rigor del trabajo desplegado. Sirva este artículo para homenajear al fundador del Instituto de Medicina Tropical Pedro Kourí y a todos los científicos que en el transcurso de estos años contribuyeron a engrandecer su nombre(AU)

In the framework of the 80th anniversary of Pedro Kouri Tropical Medicine Institute, a succinct presentation is provided of the most relevant activities in the fields of diagnosis, research and teaching so far performed by the Mycology Laboratory at the Institute. Thirty-eight years after its founding, the Laboratory continues to be one of the few places in Cuba devoted to this field and recognized for its scientific and technical achievements, which no doubt essentially respond to the national health status, without neglecting the regional and global environment. All the results presented are endorsed by over 100 publications and scientific works, which is evidence of the quality and rigor of the work done. May this paper be a tribute to the founder of Pedro Kouri Tropical Medicine Institute and all the scientists who have brought prestige to its name throughout these years(AU)

[Molecular characterization of Cryptococcus neoformans isolates from HIV patients, Guayaquil, Ecuador].

INTRODUCTION: Neurocryptococcosis is an opportunistic fungal infection that represents a high cost in human lives and for the economy of countries. Its causative agent, the Cryptococcus neoformans/Cryptococcus gattii species complex, has a sexual and an asexual phase, four major serotypes and seven molecular varieties with phenotypic, clinical-epidemiological and antifungal susceptibility differences. OBJECTIVE: To characterize by molecular methods clinical isolates of C. neoformans from Guayaquil, Ecuador. MATERIALS AND METHODS: We determined mating types, serotypes and molecular varieties by PCR and RFLP in 27 yeast isolates previously identified as C. neoformans by conventional methods. The isolates were recovered from cerebrospinal fluid of HIV seropositive patients with neurological syndrome admitted at "Dr. José Daniel Rodríguez Maridueña" Hospital from December, 2013, to January, 2015. RESULTS: We established a wide prevalence of C. neoformans serotype A, MATα and genotype VNI among the studied isolates. CONCLUSIONS: These data are similar to those obtained in other countries and the first identified by molecular characterization in Guayaquil, Ecuador. Therefore, they constitute an important contribution to the knowledge on cryptococcosis in this country.

Importance of Resolving Fungal Nomenclature: the Case of Multiple Pathogenic Species in the Cryptococcus Genus.

Cryptococcosis is a major fungal disease caused by members of the Cryptococcus gattii and Cryptococcus neoformans species complexes. After more than 15 years of molecular genetic and phenotypic studies and much debate, a proposal for a taxonomic revision was made. The two varieties within C. neoformans were raised to species level, and the same was done for five genotypes within C. gattii. In a recent perspective (K. J. Kwon-Chung et al., mSphere 2:e00357-16, 2017, https://doi.org/10.1128/mSphere.00357-16), it was argued that this taxonomic proposal was premature and without consensus in the community. Although the authors of the perspective recognized the existence of genetic diversity, they preferred the use of the informal nomenclature "C. neoformans species complex" and "C. gattii species complex." Here we highlight the advantage of recognizing these seven species, as ignoring these species will impede deciphering further biologically and clinically relevant differences between them, which may in turn delay future clinical advances.

Caracterización molecular de los aislamientos de Cryptococcus neoformans de pacientes con HIV, Guayaquil, Ecuador / Molecular characterization of Cryptococcus neoformans isolates from HIV patients, Guayaquil, Ecuador

Resumen Introducción. La neurocriptococosis es una infección fúngica oportunista que representa un alto costo en vidas humanas y para la economía de los países. Sus agentes causales, las especies del complejo Cryptococcus neoformans/Cryptococcus gattii, tienen una fase sexuada y otra asexuada, cuatro serotipos principales y siete variedades moleculares con diferencias clínico-epidemiológicas, fenotípicas y de sensibilidad a los antifúngicos. Objetivo. Caracterizar molecularmente los aislamientos clínicos de C. neoformans de Guayaquil, Ecuador. Materiales y métodos. Se determinó el tipo de apareamiento, el serotipo y la variedad molecular mediante reacción en cadena de la polimerasa y análisis del polimorfismo de los fragmentos de restricción de 27 aislamientos levaduriformes previamente identificados como C. neoformans mediante métodos convencionales. Los aislamientos fueron recuperados del líquido cefalorraquídeo de pacientes con síndrome neurológico seropositivos para HIV, internados en el Hospital de Infectología "Dr. José Daniel Rodríguez Maridueña", entre diciembre de 2013 y enero de 2015. Resultados. Se demostró el amplio predominio de C. neoformans del serotipo A, MATα y el genotipo VNI entre los aislamientos estudiados. Conclusiones. Estos datos son similares a los obtenidos en otros países y son los primeros de su tipo en Guayaquil, Ecuador, por lo cual constituyen un aporte importante al conocimiento de la criptococosisen esta ciudad.

Abstract Introduction: Neurocryptococcosis is an opportunistic fungal infection that represents a high cost in human lives and for the economy of countries. Its causative agent, the Cryptococcus neoformans/Cryptococcus gattiispecies complex, has a sexual and an asexual phase, four major serotypes and seven molecular varieties with phenotypic, clinical-epidemiological and antifungal susceptibility differences. Objective: To characterize by molecular methods clinicalisolates of C. neoformans from Guayaquil, Ecuador. Materials and methods: We determined mating types, serotypes and molecular varieties by PCR and RFLP in 27 yeast isolates previously identified as C. neoformans by conventional methods. The isolates were recovered from cerebrospinal fluid of HIV seropositive patients with neurological syndrome admitted at "Dr. José Daniel Rodríguez Maridueña" Hospital from December, 2013, to January, 2015. Results: We established a wide prevalence of C. neoformans serotype A, MATαand genotype VNI among the studied isolates. Conclusions: These data are similar to those obtained in other countries and the first identified by molecular characterization in Guayaquil, Ecuador. Therefore, they constitute an important contribution to the knowledge on cryptococcosis in this country.

Tracing Genetic Exchange and Biogeography of Cryptococcus neoformans var. grubii at the Global Population Level.

Cryptococcus neoformans var. grubii is the causative agent of cryptococcal meningitis, a significant source of mortality in immunocompromised individuals, typically human immunodeficiency virus/AIDS patients from developing countries. Despite the worldwide emergence of this ubiquitous infection, little is known about the global molecular epidemiology of this fungal pathogen. Here we sequence the genomes of 188 diverse isolates and characterize the major subdivisions, their relative diversity, and the level of genetic exchange between them. While most isolates of C. neoformans var. grubii belong to one of three major lineages (VNI, VNII, and VNB), some haploid isolates show hybrid ancestry including some that appear to have recently interbred, based on the detection of large blocks of each ancestry across each chromosome. Many isolates display evidence of aneuploidy, which was detected for all chromosomes. In diploid isolates of C. neoformans var. grubii (serotype AA) and of hybrids with C. neoformans var. neoformans (serotype AD) such aneuploidies have resulted in loss of heterozygosity, where a chromosomal region is represented by the genotype of only one parental isolate. Phylogenetic and population genomic analyses of isolates from Brazil reveal that the previously "African" VNB lineage occurs naturally in the South American environment. This suggests migration of the VNB lineage between Africa and South America prior to its diversification, supported by finding ancestral recombination events between isolates from different lineages and regions. The results provide evidence of substantial population structure, with all lineages showing multi-continental distributions; demonstrating the highly dispersive nature of this pathogen.

Susceptibilidad antifúngica de aislados vaginales de Candida spp / Antifungal susceptibility of Candida spp. vaginal isolates

Introducción: la vulvovaginitis constituye una de las principales afecciones ginecológicas, y su causa más frecuente es la candidiasis. Candida albicans se considera el agente etiológico más importante de esta entidad; sin embargo, estudios recientes revelan un incremento en la incidencia de otras especies del género. Algunas de estas tienen la particularidad de presentar resistencia a los tratamientos usuales con antimicóticos. Objetivo: evaluar la susceptibilidad antifúngica de aislados vaginales de pacientes cubanas con sospecha de candidiasis vulvovaginal que se obtuvieron en el 2015. Métodos: a 28 aislados pertenecientes al género Candida, se les realizó las pruebas de susceptibilidad in vitro con la galería ATBTM Fungus 3 frente a diferentes antifúngicos (5-fluorocitosina, anfotericina B, fluconazol, itraconazol y voriconazol). Resultados: todos los aislados fueron sensibles a la anfotericina B y uno de C. albicans se informó resistente a los azoles estudiados. Todas las especies diferentes de C. albicans fueron susceptibles al voriconazol (CMI≤ 1 mg/L). Conclusiones: el estudio de patrones de susceptibilidad en aislados de Candida provenientes de mujeres con vulvovaginitis permite profundizar en cómo abordar la terapéutica de esta afección; el fluconazol resultó el tratamiento de elección. Los resultados alertan sobre la emergencia de C. glabrata, C. krusei, C. parapsilosis, C. tropicalis, C. inconspicua y C. lusitaniae como agentes causales de la candidiasis vulvovaginal(AU)

Introduction: vulvovaginitis is one of the main gynecological diseases frequently caused by candidiasis. Candida albicans is considered as the most important etiological agent for the disease; however, recent students have revealed an increased incidence of other species of the genus. Some of them may show particular resistence to usual antimycotic treatments. Objective: to evaluate the antifungal susceptibility of vaginal isolates from Cuban female patients suspected of vulvovaginal candidiasis in 2015. Methods: twenty eight Candida genus isolates underwent in vitro susceptibility tests with ATBTM Fungus 3 using several antifungal agents (5 fluorocytosine, anphotericin B, fluconazole, itraconazole and vorixonazole). Results: all isolates were susceptible to B anphotericin and one C. albicans isolate was reported as resistant to the studied azoles. All the species other thanC. albicans were susceptible to voriconazole (CMI≤ 1mg/L). Conclusions: the study of susceptibility patterns in Candida isolates from women with vulvovaginitis allow delving into the different ways of approaching the therapeutics of this disease; fluconazole was the treatment of choice. The results show emergence of C. glabrata,C. krusei, C. parapsilosis, C. tropicalis, C. inconspicua and C. lusitaniae as causative agents of vulvovaginal candidiasis(AU)

Presentación de siete casos de tiña negra en niños / Reports of seven cases of tinea nigra in children

Introducción: la tiña negra es una micosis superficial causada por el hongo Hortaea werneckii. Se considera una micosis benigna que por lo general es observada en países tropicales. Objetivo: reportar siete casos de tiña negra en niños de dos hospitales de La Habana, Cuba. Métodos: se realizó estudio micológico (examen directo y cultivo) a partir de escamas tomadas mediante raspado de las lesiones a siete niños con diagnóstico clínico presuntivo de tiña negra palmar. Se registraron las características de las lesiones, edad, sexo y factores predisponentes de los pacientes, así como la evolución del cuadro con el tratamiento antifúngico. Resultados: se confirmó la sospecha clínica de tiña negra a través del aislamiento e identificación de Hortae werneckii. Las edades de los pacientes oscilaron entre 3 y 6 años y el 57 por ciento era del sexo femenino. La hiperhidrosis se encontró en el 43 por ciento de los casos. El tratamiento específico con antifúngicos azólicos y terbinafina tópicos fue satisfactorio en 21 días como promedio. Conclusiones: todos los casos con sospecha de tiña negra fueron confirmados de manera oportuna en el laboratorio, lo que permitió descartar enfermedades malignas y aplicar tratamiento específico(AU)

Introduction: tinea nigra is a superficial mycosis caused by the fungus Hortaea werneckii. It is considered a benign fungal infection and usually observed in tropical countries. Objective: to report seven cases of tinea nigra in children in two hospitals of Havana, Cuba. Methods: a mycological study (direct examination and culture) was made from skin scales from scraping injuries to seven children with presumptive clinical diagnosis of tinea nigra palmaris. The characteristics of the injury, age, sex and predisposing factors of patients were recorded, as well as the conditions natural history under antifungal treatment. Results: clinical suspicion of tinea nigra was confirmed through the isolation and identification of Hortae werneckii. The ages of the patients ranged from 3 to 6 years and 57 percent were female. Hyperhidrosis was found in 43 percent of the cases. Specific treatment with topical azole antifungal drugs and terbinafine was satisfactory in 21 days averagely. Conclusions: all cases suspected of tinea nigra were timely confirmed in the laboratory, a fact that permitted ruling out malignant diseases and applying specific treatment(AU)

Presentación de siete casos de tiña negra en niños / Reports of seven cases of tinea nigra in children

Introducción: la tiña negra es una micosis superficial causada por el hongo Hortaea werneckii. Se considera una micosis benigna que por lo general es observada en países tropicales. Objetivo: reportar siete casos de tiña negra en niños de dos hospitales de La Habana, Cuba. Métodos: se realizó estudio micológico (examen directo y cultivo) a partir de escamas tomadas mediante raspado de las lesiones a siete niños con diagnóstico clínico presuntivo de tiña negra palmar. Se registraron las características de las lesiones, edad, sexo y factores predisponentes de los pacientes, así como la evolución del cuadro con el tratamiento antifúngico. Resultados: se confirmó la sospecha clínica de tiña negra a través del aislamiento e identificación de Hortae werneckii. Las edades de los pacientes oscilaron entre 3 y 6 años y el 57 por ciento era del sexo femenino. La hiperhidrosis se encontró en el 43 por ciento de los casos. El tratamiento específico con antifúngicos azólicos y terbinafina tópicos fue satisfactorio en 21 días como promedio. Conclusiones: todos los casos con sospecha de tiña negra fueron confirmados de manera oportuna en el laboratorio, lo que permitió descartar enfermedades malignas y aplicar tratamiento específico(AU)

Evaluación de cuatro métodos de extracción del ADN de Histoplasma capsulatum y su uso en reacciones de PCR / Evaluation of four Histoplasma capsulatum DNA extraction methods and their use in PCR reactions

Histoplasma capsulatum es un hongo endémico de Cuba y el agente causal de la histoplasmosis. Estamicosis se presenta en forma de brotes epidémicos, afecta a las personas, independiente de su estadoinmunológico. Su diagnóstico se realiza mediante técnicas microbiológicas, serológicas e histológicas quetienen una sensibilidad moderada y son demoradas. Por lo que se hace necesario la estandarización demétodos moleculares rápidos y eficientes para el diagnóstico de esta micosis. Se evaluaron cuatro métodosde extracción del ADN (enzimático, mecánico y dos químicos: tiocianato de guanidinio y Tritón X-100) a partirde una cepa de H. capsulatum en fase filamentosa. Se determinó la concentración, la pureza, el rendimientoy la integridad del ADN mediante espectrofotometría y electroforesis en gel de agarosa. Se evaluaron dostécnicas de PCR con el ADN obtenido, con cebadores específicos de especie y otro con un cebador arbitrario. Los mejores resultados de concentración, pureza, rendimiento e integridad se obtuvieron con el método de extracción enzimático. Se logró la estandarización de las PCR con cebadores específicos,confirmándose así las 16 cepas estudiadas como H capsulatum. Con el cebador arbitrario se amplificaronsecuencias diferentes en las cepas ensayadas. Se demostró que el método de extracción enzimática brindóun ADN de buena calidad para su utilización en PCR. Este trabajo facilita el diagnóstico rápido y confiablede H. capsulatum en Cuba y brinda la posibilidad de identificar cepas con estructuras relacionadas genéticamente con los marcadores de patogenicidad y la virulencia, útiles para conformar un inmunógenovacunal(AU)

Histoplasma capsulatum is a fungus endemic from Cuba and it is the etiologic agent of histoplasmosis.This mycosis appears as epidemic outbreaks and affects people regardless their immunological status.Diagnosis of histoplasmosis is based on microbiological, histopathological and serological methods, which show moderated sensitivity or are time-consuming. Rapid and efficient molecular tools are highly demanding. Four DNA extraction methods (enzymatic, mechanic, and two chemistry: guanidine tiocianateand TX-100) were evaluated from a H. capsulatum strain in the mold phase. DNA concentration, purity,integrity and yield were estimated by spectrophotometry and agarose gel electrophoresis. Two PCRtechniques were tested using specific and arbitrary primers. The best DNA extraction method results wereobtained with the enzymatic procedure. Sixteen different Cuban H. capsulatum strains were confirmed by the PCR standardized with specific primers. Different sequences were amplified using the arbitrary primer. The enzymatic protocol is the best option for obtaining a good quality DNA for molecular analysis. This work has created a platform a faster and reliable diagnosis of H capsulatum in Cuba, and provides the ability to identify strains with genetically related structure of pathogenicity and virulence markers useful as vaccine immunogen(AU)

Diagnóstico molecular de histoplasmosis diseminada en pacientes cubanos con sida / Molecular diagnosis of disseminated histoplasmosis in Cuban AIDS patients

Introducción: Histoplasma capsulatum es el agente causal de la histoplasmosis. La forma diseminada de esta micosis de no ser tratada suele ser fatal. Objetivo: evaluar el empleo de sangre periférica para el diagnóstico molecular de histoplasmosis diseminada y comparar sus resultados con el cultivo y la detección de anticuerpos específicos. Métodos: se determinó la presencia de ADN de Histoplasma capsulatum a partir de 12 muestras de sangre de pacientes con sida y sospecha clínica de histoplasmosis diseminada, mediante dos sistemas de reacción en cadena de la polimerasa (una simple y otra anidada, que amplifican un fragmento de la región ITS y del gen Hcp100, respectivamente). Se compararon los resultados con el cultivo y la serología. Resultados: mediante la reacción en cadena de la polimerasa simple y anidada se diagnosticó con histoplasmosis diseminada a los 12 pacientes. Por cultivo resultaron positivos 6 casos (50 por ciento). Mientras que la presencia de anticuerpos anti-Histoplasma capsulatum se determinó en 3 casos (25 por ciento). Los sistemas de reacción en cadena de la polimerasa empleados mostraron elevada sensibilidad, especificidad analítica y diagnóstica en la detección de Histoplasma capsulatum en esta forma clínica. Conclusiones: los resultados del estudio sugieren que las técnicas de reacción en cadena de la polimerasa aumentan la fiabilidad del diagnóstico de la histoplasmosis cuando se utiliza en combinación con los métodos establecidos. Los sistemas de reacción en cadena de la polimerasa aplicados al diagnóstico de histoplasmosis diseminada en pacientes con sida probaron ser sistemas rápidos, específicos y sensibles(AU)

Introduction: Histoplasma capsulatum is the causal agent of histoplasmosis. If not treated, the disseminated form of this mycosis is often fatal. Objective: evaluate the use of peripheral blood for the molecular diagnosis of disseminated histoplasmosis and compare the results with those obtained by culture and detection of specific antibodies. Methods: the presence of Histoplasma capsulatum DNA was determined from 12 blood samples from patients with AIDS and clinical suspicion of disseminated histoplasmosis, using two polymerase chain reaction systems (one simple and one nested, amplifying a fragment of the ITS region and the Hcp100 gene, respectively). The results were compared with those obtained by culture and serology. Results: all 12 patients were diagnosed with disseminated histoplasmosis by simple and nested polymerase chain reaction. Culture results were positive in 6 cases (50 percent), whereas the presence of anti-Histoplasma capsulatum antibodies was determined in 3 cases (25 percent). The polymerase chain reaction systems used showed high sensitivity, and analytical and diagnostic specificity for detection of this clinical form of Histoplasma capsulatum. Conclusions: results suggest that polymerase chain reaction techniques increase the reliability of histoplasmosis diagnosis when used in combination with established methods. When used for the diagnosis of disseminated histoplasmosis in AIDS patients, polymerase chain reaction systems proved to be fast, specific and sensitive(AU)

Diagnóstico molecular de histoplasmosis diseminada en pacientes cubanos con sida / Molecular diagnosis of disseminated histoplasmosis in Cuban aids patients

Introducción: Histoplasma capsulatum es el agente causal de la histoplasmosis. La forma diseminada de esta micosis de no ser tratada suele ser fatal. Objetivo: evaluar el empleo de sangre periférica para el diagnóstico molecular de histoplasmosis diseminada y comparar sus resultados con el cultivo y la detección de anticuerpos específicos. Métodos: se determinó la presencia de ADN de Histoplasma capsulatum a partir de 12 muestras de sangre de pacientes con sida y sospecha clínica de histoplasmosis diseminada, mediante dos sistemas de reacción en cadena de la polimerasa (una simple y otra anidada, que amplifican un fragmento de la región ITS y del gen Hcp100, respectivamente). Se compararon los resultados con el cultivo y la serología. Resultados: mediante la reacción en cadena de la polimerasa simple y anidada se diagnosticó con histoplasmosis diseminada a los 12 pacientes. Por cultivo resultaron positivos 6 casos (50 por ciento). Mientras que la presencia de anticuerpos anti-Histoplasma capsulatum se determinó en 3 casos (25 por ciento). Los sistemas de reacción en cadena de la polimerasa empleados mostraron elevada sensibilidad, especificidad analítica y diagnóstica en la detección de Histoplasma capsulatum en esta forma clínica. Conclusiones: los resultados del estudio sugieren que las técnicas de reacción en cadena de la polimerasa aumentan la fiabilidad del diagnóstico de la histoplasmosis cuando se utiliza en combinación con los métodos establecidos. Los sistemas de reacción en cadena de la polimerasa aplicados al diagnóstico de histoplasmosis diseminada en pacientes con sida probaron ser sistemas rápidos, específicos y sensibles(AU)

Introduction: Histoplasma capsulatum is the causal agent of histoplasmosis. If not treated, the disseminated form of this mycosis is often fatal. Objective: evaluate the use of peripheral blood for the molecular diagnosis of disseminated histoplasmosis and compare the results with those obtained by culture and detection of specific antibodies. Methods: the presence of Histoplasma capsulatum DNA was determined from 12 blood samples from patients with AIDS and clinical suspicion of disseminated histoplasmosis, using two polymerase chain reaction systems (one simple and one nested, amplifying a fragment of the ITS region and the Hcp100 gene, respectively). The results were compared with those obtained by culture and serology. Results: all 12 patients were diagnosed with disseminated histoplasmosis by simple and nested polymerase chain reaction. Culture results were positive in 6 cases (50 percent), whereas the presence of anti-Histoplasma capsulatum antibodies was determined in 3 cases (25 percent). The polymerase chain reaction systems used showed high sensitivity, and analytical and diagnostic specificity for detection of this clinical form of Histoplasma capsulatum. Conclusions: results suggest that polymerase chain reaction techniques increase the reliability of histoplasmosis diagnosis when used in combination with established methods. When used for the diagnosis of disseminated histoplasmosis in AIDS patients, polymerase chain reaction systems proved to be fast, specific and sensitive(AU)

Conservación de cultivos de hongos de importancia médica en agua destilada / Preservation of fungal cultures of medical importance in distilled water

Introducción: en la colección de cultivos de hongos patógenos del Instituto de Medicina Tropical Pedro Kourí, como centro de referencia nacional, se conservan los agentes causales de las principales micosis humanas, con fines de diagnóstico, investigaciones y enseñanza de la microbiología médica. La conservación de cultivos fúngicos en agua destilada estéril o método de Castellani ha sido avalada como un método que garantiza porcentajes elevados de viabilidad, pureza y estabilidad de las cepas; esto unido a su bajo costo y sencillez, la convierte en una alternativa ventajosa para el mantenimiento de los microorganismos en muchos laboratorios. Objetivo: mostrar los resultados en la preservación en agua destilada estéril de las principales especies fúngicas que integran esta colección. Métodos: se evaluó la viabilidad, pureza y estabilidad de las principales características morfológicas y fisiológicas de 240 cepas de diferentes especies fúngicas pertenecientes a la colección, conservadas en agua destilada estéril. Resultados: de los cultivos, 80 port ciento se conservó en estado viable y sin contaminaciones. Los mejores resultados se obtuvieron en la preservación de los hongos productores de abundantes conidios (97 por ciento de recuperación) y las levaduras (83 por ciento), mientras que con los dermatofitos y hongos dimórficos fue de 69 y 68 por ciento, respectivamente. En 17 géneros, la recuperación de cepas viables fue superior a 60 por ciento, mientras que en 8 resultó de 100 por ciento. El tiempo de conservación fue de 15 a 20 años. Se implementó una base de datos en formato digital de la colección sobre plataforma web. Conclusiones: el método de Castellani es un método de elección para la conservación de cultivos fúngicos en laboratorios de recursos limitados(AU)

Introduction: causal agents of the main human myicoses have been preserved in the culture collection of pathogenic fungi at Pedro KourÍ Tropical Medicine Institute, a national reference center, with the purpose of using them for medical microbiology diagnoses, research and teaching. Preservation of fungal cultures in sterile distilled water, or Castellani's method, has been endorsed as a method ensuring high rates of strain viability, purity and stability, low costs and great simplicity. It is therefore an advantageous alternative for the maintenance of microorganisms in many laboratories. Objective: present the results obtained from the preservation in sterile distilled water of the main fungal species included in the collection. Methods: an evaluation was conducted of the viability, purity and stability of the main morphological and physiological characteristics of 240 strains of different fungal species from the collection, which had been preserved in sterile distilled water. Results: 80 percent of the cultures had retained their viable status without any contamination. The best results corresponded to the preservation of fungi producing abundant conidia (97 percent recovery) and yeasts (83 percent), followed by dermatophytes (69 percent) and dimorphic fungi (68 percent). In 8 genera, recovery of viable strains was 100 percent, and in 17 it was above 60 percent. Preservation time was 15-20 years. A web-based digital database was created for the collection. Conclusions: Castellani's is the method of choice for the preservation of fungal cultures in resource-limited laboratories(AU)