Phenotypic and genotypic characterization of Colombian clinical isolates of Sporothrix spp / Caracterización fenotípica y genotípica de aislamientos clínicos colombianos de Sporothrix spp

Introduction. For over a century, Sporothrix schenckii was considered the sole species responsible for sporotrichosis. In 2007, scientific community confirmed the disease could be caused by various Sporothrix species. These species differed in their virulence factors and their antifungal sensitivity. Objective. This study aims to characterize 42 Colombian clinical isolates of Sporothrix spp. phenotypically and genotypically. Materials and methods. Forty-two clinical isolates were characterized using phenotypic methods. It involved various culture media to determine their growth range at different temperatures and to assess the type and distribution of pigment and colony texture. Microscopic morphology was evaluated through microcultures, as well as the conidia diameter, type of sporulation, and morphology. Additionally, the assimilation of carbohydrates was selected as a physiological trait for species identification. Genotyping of 40 isolates was performed through partial amplification of the calmodulin gene, followed by sequence analysis. Results. Molecular studies enabled the identification of 32 isolates of S. schenckii and 8 isolates of S. globosa. The combination of phenotypic and genotypic methods eased these species characterizations and the recognition keys development based on parameters such as growth diameter at 25 and 30 °C, colony texture (membranous or velvety) on potato dextrose agar, and microscopic morphology with predominance of pigmented triangular, elongated oval globose, or subglobose conidia. Conclusions. Confirmation of the phenotypic characteristics and molecular analysis is crucial for identifying Sporothrix species and determining adequate treatment. This study represents the first phenotypical and genotypical characterization of clinical isolates of Sporothrix spp. reported in Colombia.

Introducción. Por más de un siglo se creyó que Sporothrix schenckii era la única especie responsable de la esporotricosis. Sin embargo, en el 2007, se consideró que podría ser causada por diferentes especies de Sporothrix, que difieren en sus factores de virulencia y su sensibilidad a los antifúngicos. Objetivo. Caracterizar fenotípica y genotípicamente 42 aislamientos clínicos colombianos de Sporothrix spp. Materiales y métodos. Se caracterizaron 42 aislamientos clínicos mediante métodos fenotípicos. Se usaron varios medios de cultivo para determinar el rango de crecimiento a diferentes temperaturas, el tipo y la distribución del pigmento, y la textura de las colonias. Se evaluó la morfología microscópica por microcultivos mediante la determinación del diámetro, el tipo de esporulación y la morfología de las conidias. La asimilación de carbohidratos se usó como una característica fisiológica para identificar las especies. La genotipificación de los 40 aislamientos se llevó a cabo mediante la amplificación parcial del gen que codifica para la calmodulina y se confirmó por secuenciación. Resultados. Mediante estudios moleculares, se identificaron 32 aislamientos de S. schenckii y ocho de S. globosa. La combinación de métodos fenotípicos y genotípicos permitió caracterizar las especies y construir claves para su reconocimiento, con base en parámetros como el diámetro de crecimiento a 25 y 30 °C, la textura de las colonias (membranosa, aterciopelada) en agar papa dextrosa y la morfología microscópica con predominio de conidias (triangulares pigmentadas, ovales globosas elongadas, subglobosas). Conclusiones. La caracterización fenotípica y los análisis moleculares son necesarios para identificar las especies de Sporothrix y, de esta forma, elegir el tratamiento indicado. Esta es la primera caracterización fenotípica y genotípica reportada de aislamientos clínicos colombianos de Sporothrix spp.

The conventional diagnosis challenge: Real-time PCR and nested PCR correlation with the scoring system for individuals at high-risk of Pneumocystis jirovecii pneumonia / Desafío diagnóstico: PCR anidada y en tiempo real frente a un sistema de puntuación en individuos con gran riesgo de neumonía por Pneumocystis jirovecii

Introduction. Pneumocystis jirovecii is an opportunistic fungus that affects mainly people living with HIV (CD4 cell count lower than 200 cells/ml) and other immunosuppressed patients. Since P. jirovecii does not grow on routine mycological media, diagnosis of P. jirovecii pneumonia relies on indirect evidence of its presence in respiratory samples. Objectives. To associate the results of direct immunofluorescence and two molecular methods with a score to predict P. jirovecii pneumonia in patients with AIDS. Materials and methods. A prospective study was conducted with 40 patients. A respiratory sample collected before treatment was subjected to direct immunofluorescence using the Merifluor kit, to nested PCR targeting the mitochondrial large subunit ribosomal RNA, and to the VIASURE real-time PCR kit. Results. These three techniques revealed P. jirovecii in 6, 12, and 15 samples, respectively. All positive samples by direct immunofluorescence were positive by nested PCR, and all positive samples by nested PCR amplified by real-time PCR. There was a statistically significant association between the P. jirovecii pneumonia score and the molecular methods. Two patients were early diagnosed and responded well to treatment. Conclusion. Molecular methods, especially real-time PCR, are recommended for early diagnosis of P. jirovecii pneumonia in AIDS patients.

Introducción. Pneumocystis jirovecii es un hongo oportunista que afecta principalmente a personas con HIV (recuento de CD4 menor de 200 células/ml) y a otros pacientes inmunosuprimidos. Como P. jirovecii no crece en los medios micológicos de rutina, el diagnóstico de neumonía por P. jirovecii se basa en la evidencia presente en muestras respiratorias. Objetivos. Asociar los resultados de la inmunofluorescencia directa y los de dos métodos moleculares con un puntaje para predecir la neumonía causada por P. jirovecii en pacientes con sida. Materiales y métodos. Se realizó un estudio prospectivo de 40 pacientes. Se recolectó una muestra respiratoria antes del inicio de tratamiento y se sometió a una prueba de inmunofluorescencia directa con el kit Merifluor, una PCR anidada para la amplificación de la subunidad larga del ribosoma mitocondrial y una PCR en tiempo real usando el kit VIASURE. Resultados. Estas tres técnicas evidenciaron la presencia de P. jirovecii en 6, 12 y 15 muestras, respectivamente. Todas las muestras positivas por inmunofluorescencia directa fueron positivas en la PCR anidada y todas las muestras positivas en la PCR anidada amplificaron por PCR en tiempo real. Se encontró una asociación estadística entre los valores de la neumonía causada por P. jirovecii y los métodos moleculares. Dos pacientes con diagnóstico temprano respondieron satisfactoriamente al tratamiento. Conclusión. Se recomiendan los métodos moleculares, especialmente la PCR en tiempo real, para el diagnóstico temprano de neumonía causada por P. jirovecii en pacientes con sida.

GATA2 variants in patients with non-tuberculous mycobacterial or fungal infections without known immunodeficiencies.

INTRODUCTION: Haploinsufficiency of the hematopoietic transcription factor GATA2 is associated with a broad spectrum of diseases, including infection susceptibility and neoplasms. We aimed to investigate GATA2 variants in patients with non-tuberculous mycobacterial (NTM) and/or fungal infections (FI) without known immunodeficiencies. METHOD: We performed GATA2 genotyping in patients with NTM and/or FI. RESULTS: Twenty-two patients were enrolled (seventeen FI, four NTM and one with both infections). The pathogenic variant NG_029334.1:g.16287C>T was found in one patient (4.5%) and two asymptomatic offsprings. We also found the likely-benign variant NG_029334.1:g.12080G>A (rs2335052), the benign variant NG_029334.1:g.16225C>T (rs11708606) and the variant of uncertain significance NG_029334.1:g.16201G>A (rs369850507) in 18.2%, 27.3%, and 4.5% of the cases, respectively. Malignant diseases were additionally diagnosed in six patients. CONCLUSION: Although detected in 45.4% of the patients, most GATA2 variants were benign or likely benign. Identifying a pathogenic variant was essential for driving both the patient's treatment and familial counseling. Pathogenic variants carriers should receive genetic counseling, subsequent infection prevention measures and malignancies surveillance. Additionally, case-control genotyping should be carried out in Brazil to investigate whether the observed variants may be associated with susceptibility to opportunistic infections and/or concurrent neoplasms.

GATA2 variants in patients with non-tuberculous mycobacterial or fungal infections without known immunodeficiencies

ABSTRACT Introduction Haploinsufficiency of the hematopoietic transcription factor GATA2 is associated with a broad spectrum of diseases, including infection susceptibility and neoplasms. We aimed to investigate GATA2 variants in patients with non-tuberculous mycobacterial (NTM) and/or fungal infections (FI) without known immunodeficiencies. Method We performed GATA2 genotyping in patients with NTM and/or FI. Results Twenty-two patients were enrolled (seventeen FI, four NTM and one with both infections). The pathogenic variant NG_029334.1:g.16287C>T was found in one patient (4.5%) and two asymptomatic offsprings. We also found the likely-benign variant NG_029334.1:g.12080G>A (rs2335052), the benign variant NG_029334.1:g.16225C>T (rs11708606) and the variant of uncertain significance NG_029334.1:g.16201G>A (rs369850507) in 18.2%, 27.3%, and 4.5% of the cases, respectively. Malignant diseases were additionally diagnosed in six patients. Conclusion Although detected in 45.4% of the patients, most GATA2 variants were benign or likely benign. Identifying a pathogenic variant was essential for driving both the patient's treatment and familial counseling. Pathogenic variants carriers should receive genetic counseling, subsequent infection prevention measures and malignancies surveillance. Additionally, case-control genotyping should be carried out in Brazil to investigate whether the observed variants may be associated with susceptibility to opportunistic infections and/or concurrent neoplasms.

Candida glabrata produces a melanin-like pigment that protects against stress conditions encountered during parasitism.

Aim: Melanin has been linked to pathogenesis in several fungi. They often produce melanin-like pigments in the presence of L-dihydroxyphenylalanine (L-DOPA), but this is poorly studied in Candida glabrata. Methods & materials:C. glabrata was grown in minimal medium with or without L-DOPA supplementation and submitted to a chemical treatment with denaturant and hot acid. Results:C. glabrata turned black when grown in the presence of L-DOPA, whereas cells grown without L-DOPA supplementation remained white. Biophysical properties demonstrated that the pigment was melanin. Melanized C. glabrata cells were effectively protected from azoles and amphotericin B, incubation at 42°C and macrophage killing. Conclusion: In the presence of L-DOPA, C. glabrata produces melanin, increases antifungal resistance and enhances host survival.

Aim: Melanin is a pigment that can help fungi to cause disease. Fungi often produce melanin-like pigments in the presence of L-dihydroxyphenylalanine (L-DOPA), but this is poorly studied in Candida glabrata, a yeast species that can cause human disease. Methods & materials:C. glabrata was grown in minimal medium with or without L-DOPA supplementation and submitted to a chemical treatment to isolate melanin. Results:C. glabrata turned black when grown in the presence of L-DOPA, whereas cells grown without L-DOPA supplementation remained white. Several experiments demonstrated that the black pigment was melanin. Melanized C. glabrata cells were effectively protected from antifungal drugs, incubation at 42°C and killing by cells of the immune system. Conclusion: In the presence of L-DOPA, C. glabrata produces melanin, increases antifungal resistance and has enhanced survival in contact with immunologic defense cells.

GATA2 mutation in long stand Mycobacterium kansasii infection, myelodysplasia and MonoMAC syndrome: a case-report.

BACKGROUND: GATA2 is a transcription factor that is a critical regulator of gene expression in hematopoietic cells. GATA2 deficiency presents with multi-lineage cytopenia, mycobacterial, fungal and viral infections. Patients with GATA2 mutation have a high risk of developing myelodysplastic syndrome or acute myeloid leukemia. CASE PRESENTATION: We described a 43 years-old white male with 20-year follow-up of autoimmune and thrombotic phenomena, hypothyroidism, disseminated refractory Mycobacterium kansasii infection and MonoMAC syndrome. GATA2 c.1061 C > T; p.T354 M mutation was identified after he progressed from myelodysplastic pancytopenia to refractory anemia with excess blasts type II. His relatives were also investigated and he underwent unsuccessful haematopoietic stem cell transplantation. We discuss the clinical features, genetic diagnosis and treatment of this immunodeficiency disorder. CONCLUSIONS: This case illustrates the challenge how a multidisciplinary disease should be handle. Once usual causes of immunodeficiency were excluded, clinicians should considerGATA2 deficiency in patients with myelodysplasia and long-standing Mycobacterium kansasii infection.

Monoclonal antibodies to heat shock protein 60 alter the pathogenesis of Histoplasma capsulatum.

Heat shock proteins with molecular masses of approximately 60 kDa (Hsp60) are widely distributed in nature and are highly conserved immunogenic molecules that can function as molecular chaperones and enhance cellular survival under physiological stress conditions. The fungus Histoplasma capsulatum displays an Hsp60 on its cell surface that is a key target of the cellular immune response during histoplasmosis, and immunization with this protein is protective. However, the role of humoral responses to Hsp60 has not been fully elucidated. We generated immunoglobulin G (IgG) isotype monoclonal antibodies (MAbs) to H. capsulatum Hsp60. IgG1 and IgG2a MAbs significantly prolonged the survival of mice infected with H. capsulatum. An IgG2b MAb was not protective. The protective MAbs reduced intracellular fungal survival and increased phagolysosomal fusion of macrophages in vitro. Histological examination of infected mice showed that protective MAbs reduced the fungal burden and organ damage. Organs of infected animals treated with protective MAbs had significantly increased levels of interleukin-2 (IL-2), IL-12, and tumor necrosis factor alpha and decreased levels of IL-4 and IL-10. Hence, IgG1 and IgG2a MAbs to Hsp60 can modify H. capsulatum pathogenesis in part by altering the intracellular fate of the fungus and inducing the production of Th1-associated cytokines.

Chronic disseminated histoplasmosis with lesions restricted to the mouth: case report.

We report a rare case of chronic disseminated histoplasmosis with several ulcerated lesions in the oral cavity in an alcoholic patient without human immunodeficiency virus infection, with no detectable signs and symptoms of systemic disease or extraoral manifestations. Histopathological analysis revealed chronic inflammatory process with granulomas containing Histoplasma-like organisms. The isolation of Histoplasma capsulatum provided the definitive diagnosis. Treatment with itraconazole resulted in complete remission of oral lesions. As far we aware, this is the second case report of oral histoplasmosis in an HIV negative patient described in Brazil.

Chronic disseminated histoplasmosis with lesions restricted to the mouth: case report

Reportamos um caso raro de histoplasmose crônica disseminada com diversas lesões ulceradas na cavidade oral de um paciente alcoólatra, sem o vírus da imunodeficiência humana, com nenhum outro sinal detectável ou sintomas de doença sistêmica ou manifestações extra-orais. Análise histopatológica revelou processo inflamatório crônico com granulomas contendo organismos fúngicos. O isolamento do Histoplasma capsulatum forneceu o diagnóstico definitivo. Tratamento com itraconazol resultou numa remissão completa das lesões orais. De acordo com nosso conhecimento, este é o segundo caso reportado de histoplasmose oral em um paciente HIV negativo descrito no Brasil.

Proteomic identification, nucleotide sequence, heterologous expression and immunological reactivity of the triosephosphate isomerase of Paracoccidioides brasiliensis.

An antigen of Paracoccidioides brasiliensis (Pb) was gel isolated and characterized. Endoproteinase Lys-C-digested peptides of the purified protein, which presented a molecular mass of 29 kDa and pI of 5.8, were subjected to sequence analysis of their amino acids. Searches at databases comparing the sequence of amino acids from the three peptides of the native protein revealed strong homology to triosephosphate isomerase (TPI: E.C. 5.3.1.1) from several sources. The complete cDNA and gene encoding PbTPI were obtained and both contained an open reading frame predicted to encode a 249-amino acid protein that presented all the peptides characterized in the native PbTPI. The Pbtpi gene contained six exons interrupted by five introns. Analysis performed with the deduced PbTPI suggested its usefulness in providing phylogenetic relatedness, as well as evidencing the correlation between the phylogeny provided by the deduced protein and intron positions in the cognate genes. The immunological reactivity of PbTPI was examined. The complete coding cDNA of PbTPI was overexpressed in an Escherichia coli host to produce high levels of recombinant fusion protein with glutathione S-transferase (GST) that had been purified by affinity chromatography. The purified recombinant TPI was recognized by sera of patients with confirmed paracoccidioidomycosis and not by sera of healthy individuals. Thus, recombinant PbTPI can be a valuable addition to the still small arsenal of P. brasiliensis immunoreactive proteins, which could be tested for incorporation into assays for serodiagnosis of the disease.

Histoplasma capsulatum synthesizes melanin-like pigments in vitro and during mammalian infection.

Melanin is made by several important pathogenic fungi and has been implicated in the pathogenesis of a number of fungal infections. This study investigated whether the thermally dimorphic fungal pathogen Histoplasma capsulatum var. capsulatum produced melanin or melanin-like compounds in vitro and during infection. Growth of H. capsulatum mycelia in chemically defined minimal medium produced pigmented conidia. Growth of H. capsulatum yeast in chemically defined minimal medium with L-3,4-dihydroxyphenylalanine (DOPA) or (-)-epinephrine produced pigmented cells. Treatment of the pigmented cells with proteolytic enzymes, denaturant, and hot concentrated acid yielded dark particles that were similar in size and shape to their respective propagules. Melanin-binding monoclonal antibodies (MAb) labeled pigmented conidia, yeast, and the isolated particles as determined by immunofluorescence microscopy. Electron spin resonance spectroscopy revealed that pigmented yeast cells and particles derived from pigmented cells were stable free radicals consistent with their identification as melanins. Tissues from mice infected with H. capsulatum and from biopsy specimens from a patient with histoplasmosis contained fungal cells that were labeled by melanin-binding MAb. Digestion of infected mouse tissues yielded dark particles that reacted with the melanin-binding MAb and were similar in appearance to H. capsulatum yeast cells. Additionally, sera from infected mice contained antibodies that bound melanin particles. Phenoloxidase activity capable of synthesizing melanin from L-DOPA was detected in cytoplasmic yeast cell extracts. These findings indicate that H. capsulatum conidia and yeast can produce melanin or melanin-like compounds in vitro and that yeast cells can synthesize pigment in vivo. Since melanin is an important virulence factor in other pathogenic fungi, this pigment may have a similar role to play in the pathogenesis of histoplasmosis.