RESUMO
La pythiosis es una enfermedad que se presenta en humanos y en otros mamíferos, tales como equinos, caninos y bovinos. El agente etiológico de esta patología es Pythium insidiosum, un oomycete acuático presente en diversas regiones geográficas del mundo. Las manifestaciones clínicas cutáneas de tipo granulomatoso y gastrointestinales son las presentaciones que predominan en animales infectados. La infección puede diseminarse hacia otros tejidos (ej., óseo y pulmonar). La pythiosis humana tiene cuatro formas clínicas de presentación: cutánea o subcutánea, vascular, ocular y ocasionalmente se presenta en localizaciones anatómica inusuales (ej., cerebro). En Venezuela se han reportado casos en caninos, bovinos y equinos. En este artículo se presenta una revisión actualizada de la literatura en relación a la epidemiología, ciclo de vida del agente etiológico, patogénesis, presentación clínica en animales y humanos, diagnóstico, tratamiento y los casos de pythiosis en Venezuela.
Pythiosis is a disease that occurs in humans and other mammals, such as horses, canines and cattle. The etiologic agent is Pythium insidiosum, an aquatic oomycete present in various geographic regions of the world. The cutaneous granulomatous form and gastrointestinal are common clinical presentations which predominate in infected animals. The infection can spread to other tissues (e.g. osseous and pulmonary). Human pythiosis has four clinical forms: cutaneous or subcutaneous, vascular, ocular and occasional anatomical sites may occur (e.g. brain). Cases in canines, bovines and equines have been reported in Venezuela. This article updated a review of the literature on the epidemiology, lifecycle of the etiological agent, pathogenesis, clinical presentation in animals and humans, diagnosis, treatment, and cases of pythiosis in Venezuela.
RESUMO
Enzootic bovine granulomatosis (EBG) is a disease that affects beef calves in the flooded Savanna regions of Venezuela. Although Pythium insidiosum was originally the suspected etiologic agent, nothing was done to demonstrate its presence in the infected animals. The objective of this study was to investigate the etiologic agent causing cutaneous lesions in a group of 63 calves diagnosed with EBG. The collected samples were analyzed by histopathology, immunohistochemistry, serology, and mycological techniques. The clinical manifestations of BEG included ulcerated and swollen granulomatous lesions on the limbs of young calves. Histopathological studies revealed an eosinophilic inflammatory reaction with neutrophils, giant cells and branching hyphae with the Splendore-Hoeppli phenomenon. Immunofluorescence analysis identified the branching hyphae as elements of the fungal-like organism P. insidiosum. Wet mounts in 10% KOH revealed hyaline slender branching hyaline coenocytic hyphae, but cultures from those samples were negative. Anti-P. insidiosum immunoglobulins were also demonstrated in the collected sera of the affected bovines using latex agglutination, immunodiffusion, ELISA, and Western Blot. The histopathological, immunohistochemical, and serological tests showed for the first time that P. insidiosum could be involved in epizootic bovine pythiosis.