Equine pythiosis in Egypt: clinicopathological findings, detection, identification and genotyping of Pythium insidiosum.

BACKGROUND: Equine pythiosis is an emerging, devastating disease that is hard to treat. The tumour-like nodular skin masses grow rapidly and the outcome is generally fatal, and thus early diagnosis and intervention are important. OBJECTIVES: (i) To highlight the clinical, histological and haematological findings in pythiosis, and (ii) to evaluate the efficacy of direct sample multiplex-PCR targeting the single nucleotide polymorphisms within the ribosomal DNA region for detection and genotyping of Pythium insidiosum. ANIMALS: Two hundred and twenty horses including 204 Arabian and 16 draft horses were surveyed. METHODS: Case series study diagnosis was based on clinical, pathological and haematological findings typical of P. insidiosum infection, culture identification, immunohistochemical investigation and direct sample PCR. RESULTS: The affected horses (24 of 220, 10.91%) presented with unifocal or multiple lesions on the abdomen, limbs, chest, face and mammary gland. Cases commonly had a history of access to stagnant water, ponds and intentionally flooded rice fields. Most were pregnant mares (58.33%). Histopathology revealed granulomatous reaction, blood vessel endotheliosis, heavy infiltration of eosinophils in the dermal layer, multifocal necrosis and Splendore-Hoeppli phenomenon. Unlike direct microscopy (50%) and culture (91.6%), multiplex-PCR assay identified P. insidiosum (Clade II) in all tested samples. To the best of the authors knowledge, this is the first study determining a clade of P. insidiosum causing equine pythiosis in Egypt. CONCLUSIONS AND CLINICAL IMPORTANCE: Direct sample multiplex-PCR assay is a potential tool for the early and rapid diagnosis of equine pythiosis. It overcomes limitations associated with morphological identification and provides a definitive diagnosis.

Utilização de imunoterápico no tratamento da pitiose equina / Use of immunotherapy in equine pythiosis treatment / El uso de la inmunoterapia en tratamiento de pitiosis equina

A pitiose equina é uma infecção micótica proliferativa, invasiva e ulcerativa, causada por um pseudofungo aquático denominado Pythium insidiosum pertencente ao reino Stramenopila, filo Oomycota, família Pythiaceae, gênero Pythium e espécie P. insidiosum, que atinge pele e subcutâneo, sendo responsável por formar feridas com massas granulomatosas ulcerativas acompanhada por secreções serossanguinolentas e massas necróticas denominadas kunkers. A pitiose pode atingir outras espécies além dos equinos como caninos, bovinos, ovinos, felinos e humanos, porém os equinos são os mamíferos mais atingidos. Vários protocolos para o tratamento têm sido utilizados, como métodos químicos, cirúrgico e mais recentemente imunoterápico. O presente artigo relata um caso de pitiose equina no norte do Paraná, submetido ao tratamento com imunoterapia (Pitium-vac)®, apresentando resultados positivos.

Equine Pythiosis is a fungal proliferative, invasive and ulcerative infection caused by a water pseudofungus known as Pythium insidiosum belonging to the Stramenopila kingdom, phylum Oomycota, Pythiaceae family, Pythium insidiosum genus and species, which affects the skin and subcutaneous layer, responsible for the formation of wounds with ulcerative granulomatous masses accompanied by serum-bloody secretions and necrotic masses referred to as kunkers. Pythiosis can affect species other than horses, such as dogs, cattle, sheep, cats and humans, but horses are the most widely affected mammals. Several treatment protocols have been used, such as chemical, surgical methods and more recently immunotherapy. This article reports a case of equine Pythiosis in northern Parana undergoing immunotherapy (Pitium-vac)®, with positive results.

La pitiosis equina es una infección proliferativa fúngica, invasiva y ulcerosa causada por un pseudofungo acuático llamado Pythium insidiosum perteneciente al reino Stramenopila, phylum Oomycota, familia Pythiaceae, género Pythium y especie P. insidiosum, que afecta la piel y subcutáneo, siendo responsable por formar heridas con masas granulomatosas ulcerosas acompañados de secreciones serosangrientas y masas necróticas llamadas kunkers. La pitiosis puede ocurrir en otras especies además de los equinos, como perros, ganados, ovejas, gatos y seres humanos, pero los equinos son los mamíferos más afectados. Varios protocolos para el tratamiento ya se han utilizado como métodos químicos, quirúrgicos y más recientemente la inmunoterapia. En este artículo se reporta un caso de pitiosis equina en el norte de Paraná, sometido al tratamiento con inmunoterapia (Pitium-vac) ®, con resultados positivos.