| Congresso Brasileiro de Microbiologia 2023 | Resumo: 1263-1 | ||||
Resumo:Paracoccidioidomycosis (PCM) is a neglected systemic mycosis, that may affect individuals with certain risk factors around Latin America, especially Brazil. The etiologic agents are members of the Paracoccidioides brasiliensis complex and P. lutzii. Patient, J.X.O, male, 78-years-old, farmer, born and raised in Ibipitanga (BA), with remote origins in Bahia, Paraná, Mato Grosso and Rondônia states. Starting October 2022, reported an injury near the temporomandibular joint (TMJ) and chin region, reaching the left cervical region. The lesion measured 15cm, with an erythematous, edematous, pruritic and secretive aspect, with a local burning sensation. Systemic treatment was prescribed at another service in the resident municipality (BA), without improvement (Benzetacil). In an evaluation by the medical team of the dermatology department of Hospital São Paulo (HSP), he reported being a former smoker and social drinker with a weight loss of 20 kg in the last 4 years. The initial clinical suspicion was PLECT (Paracoccidioidomycosis - PCM, Leishmaniasis, Chromoblastomycosis and Cutaneous Tuberculosis), but with lack of pulmonary involvement characteristic of PCM on chest X-ray. In order to elucidate the case, laboratory tests were requested from the Emerging Fungal Pathogens Laboratory (LAPEM) (double radial immunodiffusion serology “DID” for PCM, PCR in biopsy fragment, direct mycological examination and tissue culture). The result obtained in DID using cell free antigen (CFA) from P. lutzii (Pb01) was positive with a 1:32 titre. DNA extraction and purification were performed using the Fast DNA kit procedure and the CLS-TS component (MP Biomedicals, Vista, CA, USA), and used in a species-specific duplex PCR assay targeting the GP43 gene, revealing a 143bp fragment compatible with P. lutzii, according to Pinheiro et al. (2021). Direct mycological examination revealed pathognomonic birefringent and multi-budding yeasts of Paracoccidioides spp. and there was no fungal isolation to date. Laboratory diagnosis becomes essential to elucidate an indolent infectious process. Among the tests requested, the phenotypic methods are laborious and time-consuming, not to mention their inability to unambiguously identify P. brasiliensis and P. lutzii down to species level. Serological tests represent good screening tests but rely heavily on the strain choice and quality control for the antigenic preparation. We emphasize PCR as a tool of great relevance, with high sensitivity and specificity compared to conventional tests, that can be used in different types of samples such as sputum, biological fluids and tissue. It represents a fast, effective, and safe diagnostic tool that reduces patient waiting time for proper treatment. This case report makes a great case for the relevance of combinatory diagnostics tests in the laboratory practice, attributing a significant change in the scenario of neglected tropical diseases, contributing to an advance in the effective diagnosis and effective treatment of emerging fungal diseases.
Keywords: Paracoccidioides lutzii; endemic mycosis; systemic mycosis; PCR; diagnostic, · Double immunodifusion assay
Development Agency: CAPES (88887.159096/2017-00), CNPq (433276/2018-5), CNPq (142310/2020-4), FAPESP (2017/27265-5)
Palavras-chave: Paracoccidioides lutzii, Paracoccidioides brasiliensis , Reação em cadeia da polimerase -PCR:, Imunodifusão dupla radial , Micoses SIstemica Agência de fomento:CAPES | |||||