Entomophthoromycosis and mucormycosis as causes of pneumonia in Vietnamese potbellied pigs

Abstract

Two Vietnamese potbellied pigs ( Sus scrofa) had respiratory disease and, on autopsy, both pigs had large masses in the lungs and thoracic cavity. Microscopically, pulmonary and pleural masses contained large areas with hyphae surrounded by hypereosinophilic cellular debris rimmed by abundant eosinophils, lymphocytes, plasma cells, and histiocytes with occasional multinucleate giant cells. The hypereosinophilic debris usually formed tight cuffs, or "sleeves" around the hyphae, compatible with Splendore-Hoeppli-like material. The fungal organisms were determined by PCR to be Conidiobolus incongruus in one pig and Mucor circinelloides in the other. Entomophthoromycosis and mucormycosis should be included in the differential diagnoses for swine pneumonia, particularly when there is evidence of granulomatous pulmonary masses and pleural effusion with eosinophilic inflammation.

Case Report: Pulmonary Conidiobolomycosis in a Vietnamese Pot-Bellied Pig

“…All of these pigs were presented with respiratory signs and pleural effusion and had one or more large pulmonary granulomas identified at necropsy. Microscopically, these granulomas contained fungal hyphae surrounded by brightly eosinophilic material (Splendore-Hoeppli material and/or degranulating eosinophils), similar to the case presented here ( 3 , 17 ). In addition to pneumonia, entomophthoromycosis or mucormycosis in swine has also been implicated in submandibular abscesses, mesenteric lymphadenopathy, hepatic granulomas, and gastritis ( 18 , 19 ).…”

“…Four cases of pulmonary entomophthoromycosis and mucormycosis in Vietnamese potbellied pigs have been described and attributed to C. incongruus, Mucor circinelloides , and Peniophora spp. ( 3 , 17 ). All of these pigs were presented with respiratory signs and pleural effusion and had one or more large pulmonary granulomas identified at necropsy.…”

“…In one of these reported cases of disseminated conidiobolomycosis from a North American white-tailed deer, there was a large intrathoracic mass associated with the accessory lung lobe consisting of eosinophilic granulomatous inflammation, potentially suggestive of a primary pulmonary lesion ( 6 ). Reports of primary pulmonary conidiobolomycosis are rare, including two dogs and the two aforementioned pigs ( 3 , 5 , 17 , 23 ). The case reported herein is thought to represent a primary pulmonary conidiobolomycosis since dissemination of conidiobolomycosis to other organs was not observed grossly or histologically.…”

“…They can also exist as facultative or obligate insect pathogens ( 2 ). Among the genus Conidiobolus, C. coronatus, C. incongruus , and C. lamprauges present as specific species of pathological importance in humans and animals, including dogs, horses, sheep, goats, deer, llamas, pigs, and non-human primates ( 3 – 7 ). Conidiobolus spp.…”

Advantageous Fungi against Parasites Transmitted through Soil

“…Among animals, infection by M. circinelloides has been diagnosed in one Vietnamese potbellied pig presenting clinical signs of pneumonia, but information regarding the habitat or the level of inbreeding has not been provided [52].…”