Feline subcutaneous pythiosis

Abstract

Pythiosis in felines is a rare disease associated with the oomycete Pythium insidiosum. The aim of this report was to describe the macroscopic, histopathological, and molecular characteristics of P. insidiosum infection in a 2-year-old cat, with a localized invasive subcutaneous mass. The feline had an increase of volume near the anal region since it was younger. The cat died just after surgery. The necropsy was performed, and samples were collected for histopathological examination. Microscopically, the skin lesion was characterized by necro-eosinophilic dermatitis, panniculitis, and myositis surrounding negatively stained hyphal structures. In the sections stained with GMS, dark brown hyphae were clearly seen inside the affected tissue. They were rarely septate and their walls were almost parallel. Immunohistochemistry using a polyclonal anti-P. insidiosum antibody showed a strongly immunostained hyphae into the lesions. The analysis based on PCR had a positive result for P. insidiosum. Pythiosis should be considered in the differential diagnosis of subcutaneous tissue disorders in felines.

Invasive Fungal Infections and Oomycoses in Cats: 1. Diagnostic approach

“…✜ Geographic distribution Oomycetes causing feline IFLIs occur in tropical and subtropical regions, as well as some temperate regions such as California and Arizona. Feline pythiosis has been reported in the US Gulf States (in particular Louisi-ana), 149,150 Brazil 151-154 and Spain. 145 The authors have also diagnosed cases in Hong Kong.…”

“…Feline pythiosis has been reported in the US Gulf States (in particular Louisiana), 149,150 Brazil [151][152][153][154] and Spain. 145 The authors have also diagnosed cases in Hong Kong.…”

History and Perspective of Immunotherapy for Pythiosis

“…Direct exposure to the pathogen habitat (i.e., stagnant water, rice field, pond) could increase the risk of the infection [43][44][45][46][47]. Patients with pythiosis usually manifest with clinical features associated with an infection of the skin [11,23,48,49], artery [13,50,51], eye [47,[52][53][54], gastrointestinal tract [28,[55][56][57], or another internal organ [5,12,[58][59][60]. Diagnostic methods have been established for pythiosis [61], such as culture identification [62][63][64], histopathological examination [65][66][67][68], serological assays [69][70][71][72][73][74][75], molecular techniques [76][77][78][79][80][81][82], and proteomic analysis…”