Oscar Gomez

Prof. Oscar Gomez

Genoma CES, Universidad CES
+1

Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 January 2020 in Emerging Microbes & Infections
Verified
Journal Article
Open access
JFJoão Eudes Filho
João Eudes Filho
ISIsabele Barbieri dos Santos
Isabele Barbieri dos Santos
CRCarmélia Matos Santiago Reis
Carmélia Matos Santiago Reis
JPJosé Salvatore Leister Patané
José Salvatore Leister Patané
VPVerenice Paredes
Verenice Paredes
AAndré Moraes Nicola
André Moraes Nicola
Sporotrichosis is a subcutaneous infection caused by fungi from the genus Sporothrix. It is transmitted by inoculation of infective particles found in plant-contaminated material or diseased animals, characterizing the classic sapronotic and emerging zoonotic transmission, respectively. Since 1998, southeastern Brazil has experienced a zoonotic sporotrichosis epidemic caused by S. brasiliensis, centred in the state of Rio de Janeiro. Our observation of feline sporotrichosis cases in Brasília (Midwestern Brazil), around 900 km away from Rio de Janeiro, led us to question whether the epidemic caused by S. brasiliensis has spread from the epicentre in Rio de Janeiro, emerged independently in the two locations, or if the disease has been present and unrecognized in Midwestern Brazil. A retrospective analysis of 91 human and 4 animal cases from Brasília, ranging from 1993 to 2018, suggests the occurrence of both sapronotic and zoonotic transmission. Molecular typing of the calmodulin locus identified S. schenckii as the agent in two animals and all seven human patients from which we were able to recover clinical isolates. In two other animals, the disease was caused by S. brasiliensis. Whole-genome sequence typing of seven Sporothrix spp. strains from Brasília and Rio de Janeiro suggests that S. brasiliensis isolates from Brasília are genetically distinct from those obtained at the epicentre of the outbreak in Rio de Janeiro, both in phylogenomic and population genomic analyses. The two S. brasiliensis populations seem to have separated between 2.2 and 3.1 million years ago, indicating independent outbreaks or that the zoonotic S. brasiliensis outbreak might have started earlier and be more widespread in South America than previously recognized.

9 July 2021 in Journal of Fungi
Verified
Journal Article
Open access
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JGJuan E. Gallo
Juan E. Gallo
ITIsaura Torres
Isaura Torres
OGOscar Gomez
Oscar Gomez
LRLavanya Rishishwar
Lavanya Rishishwar
FVFredrik Vannberg
Fredrik Vannberg
OCOliver Keatinge Clay
Oliver Keatinge Clay
Histoplasmosis is a systemic fungal disease caused by the pathogen Histoplasma spp. that results in significant morbidity and mortality in persons with HIV/AIDS and can also affect immunocompetent individuals. Although some PCR and antigen-detection assays have been developed, conventional diagnosis has largely relied on culture, which can take weeks. Our aim was to provide a proof of principle for rationally designing and standardizing PCR assays based on Histoplasma-specific genomic sequences. Via automated comparisons of aligned genome contigs/scaffolds and gene (sub)sequences, we identified protein-coding genes that are present in existing sequences of Histoplasma strains but not in other genera. Two of the genes, PPK and CFP4, were used for designing primer sets for conventional and real-time PCR assays. Both resulted in a 100% analytical specificity in vitro and detected 62/62 H. capsulatum isolates using purified DNA. We also obtained positive detections of 2/2 confirmed H. capsulatum clinical FFPE (formalin-fixed paraffin-embedded) samples using both primer sets. Positive control plasmid 10-fold serial dilutions confirmed the analytical sensitivity of the assays. The findings suggest that these novel primer sets should allow for detection sensitivity and reduce false positive results/cross-reactions. New assays for detecting pathogenic fungi, constructed along these lines, could be simple and affordable to implement.

2 April 2020 in Microbiology Resource Announcements
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Journal Article
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OGOscar Gomez
Oscar Gomez
CFCarmen G. Freyle
Carmen G. Freyle
STSusana Torres
Susana Torres
ÁRÁlvaro L. Rúa
Álvaro L. Rúa
DTDiana P. Tamayo
Diana P. Tamayo
OHOrville Hernández
Orville Hernández
Aspergillus is a very diverse genus of fungi that are common in the environment and can affect human health. Here, we report the draft genome sequences of two Colombian isolates of Aspergillus tamarii , an emerging pathogenic species. One isolate was obtained from an infected patient and the other from the environment in a hospital.

31 August 2023 in Biomédica
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Journal Article
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LOLina M. Osorio-Cock
Lina M. Osorio-Cock
SJSandra Catalina Jaramillo-Pulgarín
Sandra Catalina Jaramillo-Pulgarín
AFAlba P. Ferrín-Bastidas
Alba P. Ferrín-Bastidas
DMDiana Y. Molina-Colorado
Diana Y. Molina-Colorado
OGOscar Gomez
Oscar Gomez
MJMaría del Pilar Jiménez-Alzate
María del Pilar Jiménez-Alzate
La paracoccidioidomicosis es una micosis sistémica endémica en Latinoamérica. La presentación más frecuente compromete crónicamente los pulmones, la piel y las mucosas. Al inicio, este paciente presentó, por varios años, una lesión única en la mucosa oral que, en ausencia de otros síntomas, se relacionó con una neoplasia maligna, específicamente con un carcinoma escamocelular.La diferenciación entre los dos diagnósticos se hace mediante un examen directo, un estudio histopatológico y cultivos iniciales y subsecuentes. Sin embargo, tales estudios no fueron concluyentes. Después de varias consultas y pruebas, con los resultados del examen directo, la inmunodifusión y la PCR en tiempo real se confirmó el diagnóstico de paracoccidioidomicosis crónica multifocal.Este caso alerta sobre la ausencia de sospecha clínica de micosis endémicas, dada la presencia de lesiones mucocutáneas que pueden ser producidas por hongos como Paracoccidioides spp, y la importancia de considerarlas entre los diagnósticos diferenciales.

31 August 2023 in Biomédica
Verified
Journal Article
Open access
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LÁLaura C. Álvarez-Acevedo
Laura C. Álvarez-Acevedo
MZMaría C. Zuleta-González
María C. Zuleta-González
OGOscar Gomez
Oscar Gomez
ARAlvaro Leon Rua
Alvaro Leon Rua
OHOrville Hernández-Ruiz
Orville Hernández-Ruiz
MJMaría del Pilar Jiménez-Alzate
María del Pilar Jiménez-Alzate
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.Material 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 ºC, 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.

27 January 2025 in Journal of Fungi
Verified
Journal Article
Open access
PDF file
MGMaria Camila Zuleta González
Maria Camila Zuleta González
OGOscar Gomez
Oscar Gomez
EMElizabeth Misas
Elizabeth Misas
STSusana Torres
Susana Torres
ARAlvaro Leon Rua
Alvaro Leon Rua
ALAngela Maria Lopez
Angela Maria Lopez
The genus Aspergillus comprises a diverse group of fungi that can cause a range of health issues, including systemic infections and allergic reactions. In this regard, A. fumigatus has been recognized as the most prevalent allergen-producing species. This genus taxonomic classification has been subject to frequent updates, which has generated considerable difficulties for its classification when traditional identification methodologies are employed. To demonstrate the feasibility of this approach, we sequenced the whole genomes of 81 Aspergillus isolates and evaluated a WGS-based pipeline for precise species identification. This pipeline employed two methodologies: (i) BLASTn web using four barcode genes and (ii) species tree inference by OrthoFinder. Furthermore, we conducted a prediction of allergenic capacity based on a homology analysis across all the isolated species and confirmed by RT-qPCR the expression of three orthologous allergens (Asp f 1, Asp f 3 and Asp f 22) in fifteen different Aspergillus species. The species-level identification rate with the barcoding and the species tree were calculated at 64.2% and 100%, respectively. The results demonstrated that A. fumigatus, A. flavus and A. niger were the most prevalent species. The species A. hortae, A. uvarum, A. spinulosporus, A. sydowii, A. westerdijkiae, A. amoenus and A. rhizopodus identified in this study represent the inaugural report of their presence in our region. The results of the homology analysis indicated the presence of orthologous allergens in a wide range of non-fumigatus species. This study presents a novel approach based on WGS that enables the classification of new species within the genus Aspergillus and reports the genomic sequences of a great diversity of species isolated in our geographic area that had never been reported before. Additionally, this approach enables the prediction of allergens in species other than A. fumigatus and demonstrates their genetic expression, thereby contributing to the understanding of the allergenic potential of different species within this fungal genus.