RESUMEN
A 54-year-old female farmer presented with a pea-sized red nodule on the left upper limb near the wrist for 15 days,which occurred after trauma,gradually became swollen and ruptured,and developed into multiple nodules arranged in a chain in 30 days.Skin examination revealed multiple hard purple-red nodules arranged in a line on her left upper limb,some of which were ruptured with a small amount of purulent exndate.Histopathological examination further revealed that the focus of infection manifested as pyogenic granuloma-like inflammation mainly infiltrated with mixed inflammatory cells.Periodic acid Schiff (PAS) staining showed no fungal structures,including fungal spores,hyphae and asteroid body.The biopsy tissue culture yielded the fungus.According to the morphological analysis of the cultures and results of molecular identification based on internal transcribed spacer (ITS) and calmodulin (CAL) coding regions,this case was finally diagnosed as lymphocutaneous sporotrichosis caused by Sporothrix schenckii sensu stricto.The patient was treated with oral potassium iodide 10％ solution in a dose of 10 ml thrice a day.After 2-month treatment,the patient felt that the lesions were obviously improved,but afterwards she was lost to follow-up.This research report suggests that phenotypic analysis combined with ITS/CAL-based molecular identification can accurately identify Sporothrix schenckii complex at the species level.
RESUMEN
En este estudio se desarrolló y se evaluó el ensayo por inmunoabsorción ligado a enzimas (ELISA), para la detección de anticuerpos en sueros de pacientes con esporotricosis, para lo cual se empleó un antígeno crudo de Sporothrix schenckii sensu stricto obtenido a partir de la forma micelial. Los sueros positivos para esporotricosis fueron ensayados por otras técnicas serológicas: inmunodifusión doble (IDD) y contrainmunoelectroforesis (CIE). El ensayo fue validado utilizando sueros de otras patologías como histoplasmosis, paracoccidioidomicosis, tuberculosis, leishmaniasis, lupus y sueros de individuos sanos como controles negativos. Se encontró una especificidad de 100 % con las técnicas utilizadas y una sensibilidad del antígeno de S.schenckii sensu stricto, por encima del 98% para IDD, CIE y ELISA. Estos resultados demuestran la alta sensibilidad y especificidad del antígeno de S. schenckii sensu stricto, para el diagnóstico de la esporotricosis, empleando las técnicas de IDD, CIE y ELISA. Los resultados sugieren, que este antígeno podría ser usado en conjunto con otras pruebas convencionales para el diagnóstico diferencial y puede ser útil para monitorizar la evolución de la enfermedad y respuesta al tratamiento.
We developed and analyzed an Enzyme-Linked Immunosorbent Assay (ELISA) in order to detect antibodies in sera from sporotrichosis patients. We used a crude antigen of Sporothrix schenckii sensu stricto, obtained from the mycelial phase of the fungi. Positive sera were analyzed by other serological techniques such as double immunodiffusion (IGG) and counterimmunoelectrophoresis (CIE). The assay was validated by using sera from patients with other pathologies such as: histoplasmosis, paracoccidioidomycosis, tuberculosis, leishmaniasis, lupus and healthy individuals as negative controls. For the Sporothrix schenckii sensu stricto antigen, we found a 100% of specificity by every technique and sensitivity higher than 98% with IDD, CIE and ELISA. Our results show a high sensitivity and specificity for the Sporothrix schenckii sensu stricto antigen, so it can be used for IDD, CIE and ELISA. The results suggest that this antigen could be used in conjunction with other conventional tests for differential diagnosis and may be useful for monitoring the disease progression and response to treatment.