GASTRIC PYTHIOSIS IN A BACTRIAN CAMEL (BACTRIANUS CAMELUS)

Abstract

Pythium insidiosum, an aquatic oomycete, causes chronic lesions in the skin and digestive tract of multiple species. A captive-bred Bactrian camel ( Camelus bactrianus) showed clinical signs of lethargy and weight loss in a clinical course of 30 days, with no response to treatment. At necropsy, the abdominal cavity had approximately 32 L of a yellow, turbid fluid with fibrin. The third compartment of the stomach (C-3) showed a focal area of rupture covered with fibrin. Close to this area, the C-3 wall was thickened and firm, demonstrating irregular, yellow, and friable areas on cut surface (kunkers). Microscopically, these corresponded to necrosis, characterized by a central amorphous eosinophilic material, surrounded by a pyogranulomatous inflammatory infiltrate and fibrosis. Negatively stained hyphae were observed at the periphery of the necrotic areas, which showed marked immunostaining for P. insidiosum. Pythiosis in camelids may involve the stomach, resulting in peritonitis and death.

Global Distribution and Clinical Features of Pythiosis in Humans and Animals

“…To a much lesser extent, some affected animals (n = 350; 10.2%) came with clinical manifestations associated with gastrointestinal (n = 249; 7.3%), disseminated (n = 25; 0.7%), pulmonary (n = 4; 0.1%), or other organ (n = 5; 0.1%) infection (Table 3). Gastrointestinal pythiosis (n = 249) was mostly observed in dogs (n = 235; 94.4%), but rarely detected in other animal species, such as horses (n = 5; 2.0%) [150][151][152][153][154], cats (n = 4; 1.6%) [155][156][157], sheep (n = 2; 0.8%) [158], camels (n = 1; 0.4%) [159], ostrich (n = 1) [85], and tiger (n = 1) [87] (Table 3). Disseminated pythiosis in animals usually began with a cutaneous/subcutaneous infection and progressed to the bone, liver, lung, or other organs [126][127][128][129][130][131][132]160].…”

History and Perspective of Immunotherapy for Pythiosis

“…An elevated level of IL-4 is responsible for the differentiation and proliferation of Th2 cells, which, in turn, secretes IL-5 for activating eosinophils [131,142,245,246]. This process leads to the non-protective Th2-mediated immunity, where eosinophils are predominantly recruited, together with other cell types, such as mast cells, neutrophils, giant cells, and plasma cells, into the infection area [18,28,66,160,199,217,247]. The eosinophils surround the P. insidiosum hyphae inside necrotic tissues, producing the histological phenomenon called "Splendore-Hoeppli" [49,105,[248][249][250].…”

“…Pythiosis is a life-threatening infectious disease [1][2][3][4][5][6][7] that has been increasingly reported in humans [8][9][10][11][12][13], horses [14][15][16][17][18][19], dogs [20][21][22][23], cats [24][25][26][27], camels [28,29], and some other animals [30][31][32][33][34] living in tropical and subtropical areas worldwide. The causative agent is the oomycete microorganism Pythium insidiosum, which inhabits water and moist soil [35][36][37][38][39][40].…”

“…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…”