Correlation Between Amyloid PET Imaging and Discordant Cerebrospinal Fluid Biomarkers Results in Patients with Suspected Alzheimer's Disease.

BACKGROUND: Although the concordance between cerebrospinal fluid (CSF) Alzheimer's disease (AD) biomarkers and amyloid-PET findings is well known, there are no data regarding the concordance of amyloid-PET with inconclusive CSF values of amyloid-ß (Aß)1 - 42 and p-tau for the diagnosis of AD. OBJECTIVE: To investigate the relationship between the amyloid-PET results with discordant AD biomarkers values in CSF (Aß1 - 42+/p-tau-or Aß1 - 42-/p-tau+). METHODS: An observational retrospective study, including 62 patients with mild cognitive impairment (32/62) or dementia (30/62), suspicious of AD who had undergone a lumbar puncture to determine CSF AD biomarkers, and presented discordant values in CSF between Aß1 - 42 and p-tau (Aß1 - 42+/p-tau-or Aß1 - 42-/p-tau+). All of them, underwent an amyloid-PET with 18F-Florbetaben. An extensive neuropsychological testing as part of their diagnostic process (MMSE and TMA-93), was performed, and it was also obtained the Global Deterioration Scale. RESULTS: Comparing the discordant CSF results of each patient with the cerebral amyloid-PET results, we found that in the group with Aß1 - 42+ and p-tau-CSF values, the amyloid-PET was positive in 51.2% and negative in 48.8% of patients, while in the group with Aß1 - 42-and p-Tau+ CSF values, the amyloid-PET was positive in 52.6% of patients and negative in 47.4% of them. No significant association was found (p = 0.951) between the results of amyloid-PET and the two divergent groups in CSF. CONCLUSIONS: No significant relationship was observed between the results of discordant AD biomarkers in CSF and the result of amyloid-PET. No trend in amyloid-PET results was observed in relation to CSF biomarker values.

Central Nervous System Histoplasmosis: An Updated Insight.

Histoplasmosis is one of the systemic mycoses that can involve the Central Nervous System (CNS), and it is caused by the dimorphic ascomycete species of the Histoplasma capsulatum complex. Once in the CNS, this pathogen causes life-threatening injuries that are associated with clinical manifestations of meningitis, focal lesions (abscesses, histoplasmomas), and spinal cord injuries. The present review provides updated data and highlights a particular vision regarding this mycosis and its causative agent, as well as its epidemiology, clinical forms, pathogenesis, diagnosis, and therapy, focusing on the CNS.

Causas de muerte de los fallecidos en hemodiálisis iterada

Introducción: La hemodiálisis es la terapia de remplazo renal más utilizada en Latinoamérica y en Cuba. Se calcula que para el año 2030 la cantidad de pacientes que inician el tratamiento de reemplazo renal a nivel mundial aumentará a más del 50 % con respecto al año 2010. Objetivo: Caracterizar los pacientes en tratamiento de hemodiálisis iterada. Métodos: Se realizó un estudio descriptivo, transversal, de todos los pacientes en tratamiento de HDI del Instituto de Nefrología "Dr. Abelardo Buch López" (INEF), fallecidos en el período 2013-2018. Los datos se obtuvieron del registro de fallecidos, del registro de pacientes en hemodiálisis y de la historia clínica. El procesamiento fue realizado de forma automatizada (IBM Spss 22.0). Se calcularon tasas brutas de mortalidad y fue utilizada la técnica de análisis de distribución de frecuencias. Resultados: La tasa de mortalidad del período resultó ser 20,3 por cada 100 pacientes. El 60,9 % de los pacientes fallecidos tenían entre 60 y 79 años de edad. La hipertensión arterial (HTA) fue la enfermedad de base más frecuente (55,5 %), y la comorbilidad predominante (87,3 %). El 53,6 % de los pacientes fallecidos empleaba catéter venoso central, y el 70 % tenía menos de 5 años en HD. La principal causa de muerte fue la enfermedad cardiovascular (46,4 %). Conclusiones: En el INEF la mortalidad en hemodiálisis se comportó de manera estable. Similar a otros reportes de servicios de hemodiálisis, los fallecidos se caracterizaron en su mayoría por tener catéter venoso central para hemodiálisis y menos de cinco años en el tratamiento. Las causas de muerte presentaron el mismo patrón que las reportadas en análisis nacionales e internacionales.

Introduction: Hemodialysis is the most used renal replacement therapy in Latin America and in Cuba. It is estimated that by the year 2030 the number of patients starting therapy worldwide will increase to more than 50% compared to 2010. Objectives: To characterize the patients undergoing iterated hemodialysis treatment. Methods: A descriptive, cross-sectional study of all patients undergoing repeated hemodialysis treatment, who deceased in the period 2013-2018 was carried out at Dr. Abelardo Buch López Institute of Nephrology. The processing was done in an automatically (IBM Spss 22.0). Gross mortality rates were calculated and the frequency distribution analysis technique was used. Results: The mortality rate for the period was 20.3 per 100 patients. 60.9% of the deceased patients were between 60 and 79 years of age. Arterial hypertension was the most frequent underlying disease (55.5%), and the predominant comorbidity (87.3%). 53.6% of the deceased patients used a central venous catheter, and 70% had been on hemodialysis for less than 5 years. The main cause of death was cardiovascular disease (46.4%). Conclusions: At Dr. Abelardo Buch López Institute of Nephrology mortality in hemodialysis behaved in a stable manner. Similar to other reports of hemodialysis services, the deceased were mostly characterized by having a central venous catheter for hemodialysis and less than five years in treatment. The causes of death showed the same pattern as those reported in national and international analyses.

Considerations about the Geographic Distribution of Histoplasma Species.

Histoplasmosis is a mycotic infection principally affecting pulmonary tissue; sometimes, histoplasmosis can progress into a systemic disease. This infection involves immunocompetent and immunosuppressed human and other mammalian hosts, depending on particular circumstances. Histoplasmosis infection has been documented worldwide. The infection is acquired by inhaling infective mycelial propagules of the dimorphic fungus Histoplasma capsulatum. New reports of clinical cases of histoplasmosis in extreme latitudes could be related to human social adaptations and climate changes in the world, which are creating new favorable environments for this fungus and for bats, its major natural reservoirs and dispersers. Histoplasma has been isolated from most continents, and it is considered a complex of cryptic species, consisting of various groups of isolates that differ genetically and correlate with a particular geographic distribution. Based on updated studies, Histoplasma taxonomy is adjusting to new genetic data. Here, we have suggested that Histoplasma has at least 14 phylogenetic species distributed worldwide and new genotypes that could be under deliberation. Histoplasma's geographic radiation began in South America millions of years ago when the continents were joined and the climate was favorable. For fungal spreading, the role of bats and some birds is crucial, although other natural factors could also participate.

Susceptibilidad antimicrobiana de bacterias aisladas en sepsis del acceso vascular. Instituto de Nefrología, 2019 / Antimicrobial susceptibility of bacteria isolated from vascular access sepsis. Institute of Nephrology, 2019

Introducción: El acceso vascular en hemodiálisis es esencial para el enfermo renal por su repercusión en la calidad de vida. La fístula arteriovenosa, los catéteres para hemodiálisis o las prótesis vasculares, aunque han evolucionado gradualmente hacia el perfeccionamiento, son proclives a las infecciones debidas fundamentalmente a bacterias de la microbiota de la piel y mucosas. Objetivo: Caracterizar la susceptibilidad antimicrobiana de las bacterias aisladas de pacientes con sepsis del acceso vascular en el servicio de hemodiálisis del Instituto de Nefrología. Material y Métodos: Estudio de corte transversal, en el período comprendido entre enero a diciembre de 2019. El universo estuvo constituido por 112 aislamientos obtenidos a partir de muestras de hemocultivos, secreciones y puntas de catéter de los pacientes con bacteriemias, sepsis o secreción en el sitio de inserción del catéter o acceso vascular. Resultados: El 72,3 por ciento de las muestras estudiadas fueron hemocultivos. Se obtuvo 38,3 % de aislamientos de Staphylococcus aureus, sensibles en su totalidad a la vancomicina. El 68,1 % de las cepas de Escherichia coli fueron productoras de betalactamasas de espectro extendido (BLEE) con sensibilidad superior a 60 % a aminoglucósidos y carbapenémicos; similar patrón de sensibilidad mostraron las cepas de Pseudomonas, no obstante, el 100% fue resistente a las cefalosporinas. Conclusiones: No se reportó resistencia a la vancomicina en el estudio. Los aislamientos de los gérmenes gramnegativos mostraron elevada resistencia a las cefalosporinas y una buena sensibilidad a aminoglucósidos y carbapenémicos(AU)

Introduction: The vascular access in hemodialysis is essential for the renal patient both for its associated morbidity and mortality as well as for its impact on quality of life. Although arteriovenous fistula, hemodialysis catheters or vascular prostheses have gradually evolved toward improvement, they are prone to infections primarily due to bacteria on the skin and mucosal microbiota. Objective: To characterize the antimicrobial susceptibility of bacteria isolated from patients with vascular access sepsis in the hemodialysis service of the Institute of Nephrology. Material and Methods: A cross-sectional study was conducted in the period January-December 2019. The universe consisted of all 112 isolates obtained from blood culture samples, secretions and catheter tips from patients with bacteremia, sepsis or discharge at the site of catheter insertion or vascular access. Results: The results show that 72.3% of the samples studied were blood cultures. Also, 38.3 percent of Staphylococcus aureus isolates, which were totally sensitive to vancomycin, were obtained. On the other hand, 68.1% of Escherichia coli strains were extended spectrum beta-lactamases (ESBL) producers with sensitivity to aminoglycosides and carbapenems greater than 60%. Pseudomonas strains exhibited a similar pattern of sensitivity, however, 100% were resistant to cephalosporins. Conclusions: No resistance to vancomycin was reported in this study. Gram-negative isolates showed high resistance to cephalosporins and good sensitivity to aminoglycosides and carbapenems(AU)

Diagnostic accuracy of antigen detection in urine and molecular assays testing in different clinical samples for the diagnosis of progressive disseminated histoplasmosis in patients living with HIV/AIDS: A prospective multicenter study in Mexico.

BACKGROUND: The progressive disseminated histoplasmosis (PDH) has been associated with severe disease and high risk of death among people living with HIV (PLWHIV). Therefore, the purpose of this multicenter, prospective, double-blinded study done in ten Mexican hospitals was to determine the diagnostic accuracy of detecting Histoplasma capsulatum antigen in urine using the IMMY ALPHA Histoplasma EIA kit (IAHE), clarus Histoplasma GM Enzyme Immunoassay (cHGEI IMMY) and MiraVista Histoplasma Urine Antigen LFA (MVHUALFA); as well as the Hcp100 and 1281-1283220SCAR nested PCRs in blood, bone-marrow, tissue biopsies and urine. METHODOLOGY/PRINCIPAL FINDINGS: We included 415 PLWHIV older than 18 years of age with suspicion of PDH. Using as diagnostic standard recovery of H. capsulatum in blood, bone marrow or tissue cultures, or histopathological exam compatible, detected 108 patients (26%, [95%CI, 21.78-30.22]) with proven-PDH. We analyzed 391 urine samples by the IAHE, cHGEI IMMY and MVHUALFA; the sensitivity/specificity values obtained were 67.3% (95% CI, 57.4-76.2) / 96.2% (95% CI, 93.2-98.0) for IAHE, 91.3% (95% CI, 84.2-96.0) / 90.9% (95% CI, 87.0-94.0) for cHGEI IMMY and 90.4% (95% CI, 83.0-95.3) / 92.3% (95% CI, 88.6-95.1) for MVHUALFA. The Hcp100 nested PCR was performed on 393, 343, 75 and 297, blood, bone marrow, tissue and urine samples respectively; the sensitivity/specificity values obtained were 62.9% (95%CI, 53.3-72.5)/ 89.5% (95%CI, 86.0-93.0), 65.9% (95%CI, 56.0-75.8)/ 89.0% (95%CI, 85.2-92.9), 62.1% (95%CI, 44.4-79.7)/ 82.6% (95%CI, 71.7-93.6) and 34.9% (95%CI, 24.8-46.2)/ 67.3% (95%CI, 60.6-73.5) respectively; and 1281-1283220SCAR nested PCR was performed on 392, 344, 75 and 291, respectively; the sensitivity/specificity values obtained were 65.3% (95% CI, 55.9-74.7)/ 58.8% (95%CI, 53.2-64.5), 70.8% (95%CI, 61.3-80.2)/ 52.9% (95%CI, 46.8-59.1), 71.4% (95%CI, 54.7-88.2)/ 40.4% (95%CI, 26.4-54.5) and 18.1% (95%CI, 10.5-28.1)/ 90.4% (95%CI, 85.5-94.0), respectively. CONCLUSIONS/SIGNIFICANCE: The cHGEI IMMY and MVHUALFA tests showed excellent performance for the diagnosis of PDH in PLWHIV. The integration of these tests in clinical laboratories will certainly impact on early diagnosis and treatment.

Factores relacionados con la supervivencia de pacientes que inician tratamiento de hemodiálisis. Instituto de Nefrología / Factors related to the survival of patients who start receiving hemodialysis. Institute of Nephrology

Introducción: La enfermedad renal crónica constituye un problema de salud por su impacto sobre los individuos, la sociedad y la economía. Existe un insuficiente conocimiento de los factores relacionados con la supervivencia en los pacientes que inician hemodiálisis en nuestro medio. Objetivo: Identificar los factores relacionados con la supervivencia de los pacientes que iniciaron hemodiálisis. Material y Métodos: Se realizó un estudio descriptivo de corte retrospectivo, de pacientes que iniciaron hemodiálisis en el Instituto de Nefrología Dr. Abelardo Buch en el período del 1 de enero de 2011 al 31 de diciembre de 2016. Se analizaron variables sociodemográficas y clínicas, y se realizó una correlación de estas con la supervivencia en hemodiálisis. Para todas las pruebas realizadas se fijó un nivel de significación ɑ= 0.05. Resultados: Se estudiaron 81 pacientes, con edad media de 55 años y predominio del sexo masculino (61,7 por ciento) y la raza blanca (59,3 por ciento). Los resultados estadísticamente significativos fueron la desnutrición (Índice de Masa Corporal < 18.5 kg/m2), con una mediana de supervivencia de (7,6+-4,9; log Rank: 0,015), las cifras de albúmina sérica menores a 35 g/L, con (33.1 +-5.4; log Rank: 0.050) la falta de seguimiento nefrológico previo, con (21,5 +-2,6; log Rank: 0,041), y el empleo de catéter venoso central como acceso vascular, con (32,4+-3,5; log Rank: 0,038). Conclusiones: La desnutrición, la hipoalbuminemia, el empleo de catéter venoso central como acceso vascular y la falta de seguimiento nefrológico previo afectaron negativamente la supervivencia de los pacientes en hemodiálisis(AU)

Introduction: Chronic kidney disease is a health problem because of its impact on individuals, society and the economy. There is not enough knowledge of the factors related to survival in patients who start hemodialysis in our environment. Objective: To identify the factors related to the survival of patients who started receiving hemodialysis. Material and Methods: A descriptive retrospective study was conducted in 81 patients who started receiving hemodialysis in the Dr. Abelardo Buch Institute of Nephrology in the period between January 1, 2011 and December 31, 2016. Sociodemographic and clinical variables were analyzed. A correlation between these variables and survival was made. The level of significance in all the tests performed was determined to be ɑ= 0.05. Results: A total of 81 patients were studied. The mean age was 55 years. The male sex (61,7 percent) and the white race (59,3 percent) predominated in the study. The statistically significant variables were malnutrition (body mass index < 18.5 kg/m2) with a median survival of (7,6+-4,9; log rank: 0,015), serum albumin levels lower than 35 g/L, with (33.1 +-5.4; log rank: 0.050), lack of previous nephrological follow-up, with (21,5 +-2,6; log rank: 0,041) and the use of central venous catheter as vascular access with (32,4+-3,5; log rank: 0,038). Conclusions: Malnutrition, hypoalbuminemia, the use of central venous catheter as vascular access and previous nephrological follow-up negatively affected the survival of patients on hemodialysis (AU)

Differential diagnosis of HaNDL syndrome in a case report of a pediatric patient: The role of SPECT with 99mTc-HMPAO.

•HaNDL syndrome may be a condition probably underdiagnosed in pediatric age.•A differential diagnosis with viral, vascular or autoimmune etiology is necessary.•Epileptiform alterations in EEG could be possible in this infrequent syndrome.•99mTc-HMPAO SPECT provides a potential role in the differential diagnostic and management.

Novel clinical and dual infection by Histoplasma capsulatum genotypes in HIV patients from Northeastern, Brazil.

Histoplasmosis is a worldwide-distributed deep mycosis that affects healthy and immunocompromised hosts. Severe and disseminated disease is especially common in HIV-infected patients. At least 11 phylogenetic species are recognized and the majority of diversity is found in Latin America. The northeastern region of Brazil has one of the highest HIV/AIDS prevalence in Latin America and Ceará State has one of the highest death rates due to histoplasmosis in the world, where the mortality rate varies between 33-42%. The phylogenetic distribution and population genetic structure of 51 clinical isolates from Northeast Brazil was studied. For that morphological characteristics, exoantigens profile, and fungal mating types were evaluated. The genotypes were deduced by a MSLT in order to define local population structure of this fungal pathogen. In addition, the relationships of H. capsulatum genotypes with clinically relevant phenotypes and clinical aspects were investigated. The results suggest two cryptic species, herein named population Northeast BR1 and population Northeast BR2. These populations are recombining, exhibit a high level of haplotype diversity, and contain different ratios of mating types MAT1-1 and MAT1-2. However, differences in phenotypes or clinical aspects were not observed within these new cryptic species. A HIV patient can be co-infected by two or more genotypes from Northeast BR1 and/or Northeast BR2, which may have significant impact on disease progression due to the impaired immune response. We hypothesize that co-infections could be the result of multiple exposure events and may indicate higher risk of disseminated histoplasmosis, especially in HIV infected patients.

Histoplasma capsulatum and Pneumocystis jirovecii coinfection in hospitalized HIV and non-HIV patients from a tertiary care hospital in Mexico.

BACKGROUND: Histoplasma capsulatum and Pneumocystis jirovecii are respiratory fungal pathogens that principally cause pulmonary disease. Coinfection with both pathogens is scarcely reported. This study detected this coinfection using specific molecular methods for each fungus in the bronchoalveolar lavage (BAL) of patients from a tertiary care hospital. MATERIALS AND METHODS: BAL samples from 289 hospitalized patients were screened by PCR with specific markers for H. capsulatum (Hcp100) and P. jirovecii (mtLSUrRNA and mtSSUrRNA). The presence of these pathogens was confirmed by the generated sequences for each marker. The clinical and laboratory data for the patients were analyzed using statistical software. RESULTS: The PCR findings separated three groups of patients, where the first was represented by 60 (20.8%) histoplasmosis patients, the second by 45 (15.6%) patients with pneumocystosis, and the last group by 12 (4.2%) patients with coinfection. High similarity among the generated sequences of each species was demonstrated by BLASTn and neighbor-joining algorithms. The estimated prevalence of H. capsulatum and P. jirovecii coinfection was higher in HIV patients.

Mixed infection by Histoplasma capsulatum isolates with different mating types in Brazilian AIDS-patients.

Mixed infection by Histoplasma capsulatum isolates with different mating types, in AIDS-patients are described in this study. Morphological, mating type-specific PCR assay and multilocus sequencing type analysis of H. capsulatum isolates recovered from two Brazilian AIDS-patients were performed. Five H. capsulatum isolates were recovered at different times from the two patients. Three isolates were obtained from bone marrow (day 1 - CE0411) and buffy coat cultures (day 1 - CE0311; day 2 - CE0511) of patient 1, and two isolates were isolated from buffy coat cultures (day 3 - CE2813; day 12 - CE2513) of patient 2. The mycelial colonies depicted different textures and pigmentation features. Dimorphic conversion to the yeast-phase in ML-Gema medium was achieved in all isolates. MAT1-1 idiomorph was identified in CE0311, CE0411 and CE2813 isolates; MAT1-2 idiomorph was found in CE0511 and CE2513 isolates. These H. capsulatum isolates were grouped within LAm A clade, highlighting that CE0311 and CE0411 isolates formed a subgroup supported by a high bootstrap value. The CE0511, CE2513, and CE2813 isolates clustered together with a Brazilian H151 isolate. This research reports mixed infections caused by H. capsulatum isolates with different mating types in Brazilian AIDS-patients for the first time in the literature.

Diagnóstico de vasculitis en estudio 18F-FDG PET/TC en paciente con fiebre de origen desconocido / Diagnosis of vasculitis with 18F-FDG PET/CT study in patient with fever of unknown origin

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Trabajo colaborativo en el aula, bullying y cyberbullying: Estudio con adolescentes / Collaborative work in the classroom, bullying and cyberbullying: Study with adolescents

El acoso escolar se ha convertido en una práctica común entre adolescentes y especialmente a través del cyberbullying. Estas prácticas generan graves problemas en un colectivo en desarrollo cognitivo, social y emocional, siendo esencial actuar preventivamente. Se realizó un estudio de tipo descriptivo y corte transversal en una muestra de 227 adolescentes de Melilla (España), el cual perseguía analizar las relaciones existentes entre bullying, cyberbullying y prácticas de trabajo cooperativo. Se emplean como principales instrumentos el test de cyberbullying (Garaigordobil, 2013)y un cuestionario de trabajo en equipo mediante validación de expertos. Los resultados revelan que el trabajo cooperativo es más elevado en las chicas, disminuyendo el mismo con la edad. El trabajo grupal se relacionó inversamente con las situaciones de acoso. También se observó que a mayor edad se sufre más victimización ligada a cyberbullying e incrementan las situaciones en las que se es agresor. Se concluye cómo el trabajo cooperativo en las aulas puede actuar preventivamente ante situaciones de acoso al ayudar a construir mejores relaciones entre pares e identidad de grupo

Bullying has become a common practice in the adolescent population, and especially through cyberbullying. These practices generate serious problems in this collective, especially in cognitive, social and emotional dimensions, being essential to act preventively. A descriptive and cross-sectional study was conducted in a sample of 227 adolescents from the city of Melilla (Spain), which sought to analyze the existing relationships between bullying, cyberbullying and cooperative work practices. The cyberbullying test (Garaigordobil, 2013) and a teamwork questionnaire using validation of experts are used as main instruments. The results reveal that cooperative work is higher in girls, decreasing it as age increases. Likewise, group work was inversely related to situations of harassment. It was also observed that the older age suffered more victimization linked to cyberbullying and increased the situations in which one is an aggressor. It concludes how cooperative work in the classroom can act preventively in situations of bullying by helping to build better relationships between peers and group identity

SPECT/TC con leucocitos autólogos marcados con 99mTc-HMPAO y reconstrucción 3D híbrida en el diagnóstico de proceso infeccioso no filiado en pie / Hybrid SPECT/CT using 3D reconstruction with 99mTc-HMPAO-labeled leukocytes in the diagnosis of an infectious process of unknown origin in foot

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Genetic diversity of Histoplasma and Sporothrix complexes based on sequences of their ITS1-5.8S-ITS2 regions from the BOLD System / Diversidad genética de los complejos Histoplasma y Sporothrix en función de las secuencias de sus regiones ITS1-5.8S-ITS2 del BOLD System

High sensitivity and specificity of molecular biology techniques have proven usefulness for the detection, identification and typing of different pathogens. The ITS (Internal Transcribed Spacer) regions of the ribosomal DNA are highly conserved non-coding regions, and have been widely used in different studies including the determination of the genetic diversity of human fungal pathogens. This article wants to contribute to the understanding of the intra- and interspecific genetic diversity of isolates of the Histoplasma capsulatum and Sporothrix schenckii species complexes by an analysis of the available sequences of the ITS regions from different sequence databases. ITS1-5.8S-ITS2 sequences of each fungus, either deposited in GenBank, or from our research groups (registered in the Fungi Barcode of Life Database), were analyzed using the maximum likelihood (ML) method. ML analysis of the ITS sequences discriminated isolates from distant geographic origins and particular wild hosts, depending on the fungal species analyzed. This manuscript is part of the series of works presented at the "V International Workshop: Molecular genetic approaches to the study of human pathogenic fungi" (Oaxaca, Mexico, 2012 (AU)

Las técnicas de biología molecular han proporcionado instrumentos de alta sensibilidad y especificidad, útiles para la detección, identificación y tipificación de diferentes patógenos. Las regiones ITS (Internal Transcribed Spacer) del ADN ribosómico están altamente conservadas y no son codificantes. Estas regiones se han utilizado ampliamente en diferentes tipos de estudios, incluida la determinación de la diversidad genética de hongos patógenos del ser humano. La finalidad de este artículo es contribuir al conocimiento de la diversidad genética intra- e interespecífica de aislamientos de los complejos de Histoplasma capsulatum y Sporothrix schenckii a través del análisis de las secuencias disponibles de las regiones ITS en distintos bancos de secuencias. Las secuencias de las regiones ITS1-5.8S-ITS2, de cada hongo, depositadas en el GenBank, junto con las obtenidas por nuestros grupos de investigación (depositadas en la Fungal Barcoding of Life Database), se analizaron con el método de máxima probabilidad (ML, por sus siglas en inglés). El análisis ML de las secuencias de las regiones ITS discriminó aislamientos de orígenes geográficos distantes y de huéspedes salvajes particulares, de acuerdo con la especie fúngica analizada.Este artículo forma parte de una serie de estudios presentados en el «V International Workshop: Molecular genetic approaches to the study of human pathogenic fungi» (Oaxaca, México, 2012) (AU)

Genetic diversity of Histoplasma and Sporothrix complexes based on sequences of their ITS1-5.8S-ITS2 regions from the BOLD System.

High sensitivity and specificity of molecular biology techniques have proven usefulness for the detection, identification and typing of different pathogens. The ITS (Internal Transcribed Spacer) regions of the ribosomal DNA are highly conserved non-coding regions, and have been widely used in different studies including the determination of the genetic diversity of human fungal pathogens. This article wants to contribute to the understanding of the intra- and interspecific genetic diversity of isolates of the Histoplasma capsulatum and Sporothrix schenckii species complexes by an analysis of the available sequences of the ITS regions from different sequence databases. ITS1-5.8S-ITS2 sequences of each fungus, either deposited in GenBank, or from our research groups (registered in the Fungi Barcode of Life Database), were analyzed using the maximum likelihood (ML) method. ML analysis of the ITS sequences discriminated isolates from distant geographic origins and particular wild hosts, depending on the fungal species analyzed. This manuscript is part of the series of works presented at the "V International Workshop: Molecular genetic approaches to the study of human pathogenic fungi" (Oaxaca, Mexico, 2012).

Comparison of PCR protocols for detecting Histoplasma capsulatum DNA through a multicenter study

Background. A multicenter study was conducted. A panel containing DNA from Histoplasma capsulatum, as well as negative and cross-reaction controls, was sent to five different laboratories, members of the MICOMOL network from CYTED Program. Aims. The objective was to assess the accuracy of different PCR protocols to detect H. capsulatum DNA. Methods. Seven different PCR protocols were tested. They were based on PCR techniques and used unicopy and multicopy targets. Results. Most of these protocols (4/7) were able to detect the smallest amounts of fungal DNA (102 fg/ml). Overall sensitivity was 86% and specificity was 100%. The protocol based on a unicopy target (SCAR220) presented lower sensitivity (43%) but 100% specificity. The real-time protocols tested were highly reproducible, sensitive, and specific. Neither false positives nor cross-reactions were detected in any protocol. Conclusions. All laboratories were able to amplify H. capsulatum DNA, and real-time PCR seems to be a promising tool to efficiently detect this pathogen in clinical samples (AU)