Systemic Conidiobolus incongruus infection and hypertrophic osteopathy in a white-tailed deer (Odocoileus virginianus)

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

An adult castrated male Vietnamese pot-bellied pig had a 1-week history of acute dyspnea and lethargy. Minimal diagnostic testing was authorized by the owner, resulting in treatment with a third-generation cephalosporin and a non-steroidal anti-inflammatory drug. Partial improvement was observed after a week; however, the pig died 2 weeks after the initial onset of clinical signs. Macroscopically, ~90% of the left lung was effaced by large masses with a caseonecrotic center. Histologic examination revealed eosinophilic granulomas with myriad, intralesional, negatively staining hyphae highlighted by "sleeves" of hypereosinophilic material (Splendore-Hoeppli material). Infection with an oomycete or "zygomycete" (i.e., organisms of the order Entomophthorales or Mucorales) was initially considered. Pan-fungal PCR and sequencing performed on formalin-fixed, paraffin-embedded lung tissue identified Conidiobolus spp., consistent with a diagnosis of primary pulmonary conidiobolomycosis. There are only a few reports of infections with Conidiobolus spp. (and other members of the order Entomophthorales) in swine. Unlike humans and other animal species, conidiobolomycosis in pigs presents more commonly as a primary pulmonary disease rather than rhinofacial or nasopharyngeal disease.

Disseminated Mycobacterium kansasii infection in a white-tailed deer and implications for public and livestock health

We document a case of Mycobacterium kansasii, a rare, zoonotic bacterium, in a white-tailed deer (WTD; Odocoileus virginianus) in East Baton Rouge Parish, Louisiana. Grossly, the deer had fibrinous pleuropneumonia with yellow, mineralized nodules scattered throughout the lungs and extending to the pleura. The kidneys were enlarged and had numerous pale foci in the cortex. Microscopically, the pulmonary architecture was replaced by variably sized, multifocal-to-coalescing granulomas with peripheral histiocytes and fewer multinucleate giant cells, and necrotic centers with mineralization and hemorrhage. The latter rarely contained one to a few acid-fast, slender, 7-µm long bacteria, for which beaded morphology was sometimes evident. Similar acid-fast bacteria were also within histiocytes in the kidney. PCR assay of fresh lung sample and subsequent sequencing revealed a non-tuberculosis mycobacterium, M. kansasii. These lesions were similar to those that result from infection with M. bovis in WTD. Both M. bovis and M. kansasii are zoonotic. WTD are a reservoir of M. bovis, which is a major concern in regions in which WTD and cattle can come into close contact.

Human Pathogenic Entomophthorales

The pathogenic entomophthoralean fungi cause infection in insects and mammalian hosts. Basidiobolus and Conidiobolus species can be found in soil and insect, reptile, and amphibian droppings in tropical and subtropical areas. The life cycles of these fungi occur in these environments where infecting sticky conidia are developed. The infection is acquired by insect bite or contact with contaminated environments through open skin. Conidiobolus coronatus typically causes chronic rhinofacial disease in immunocompetent hosts, whereas some Conidiobolus species can be found in immunocompromised patients. Basidiobolus ranarum infection is restricted to subcutaneous tissues but may be involved in intestinal and disseminated infections. Its early diagnosis remains challenging due to clinical similarities to other intestinal diseases. Infected tissues characteristically display eosinophilic granulomas with the Splendore-Höeppli phenomenon. However, in immunocompromised patients, the above-mentioned inflammatory reaction is absent. Laboratory diagnosis includes wet mount, culture serological assays, and molecular methodologies. The management of entomophthoralean fungi relies on traditional antifungal therapies, such as potassium iodide (KI), amphotericin B, itraconazole, and ketoconazole, and surgery. These species are intrinsically resistant to some antifungals, prompting physicians to experiment with combinations of therapies. Research is needed to investigate the immunology of entomophthoralean fungi in infected hosts. The absence of an animal model and lack of funding severely limit research on these fungi.

Hypertrophic Osteopathy Associated with Mycotic Pneumonia in a Roe Deer ( Capreolus capreolus)

Aspergillus fumigatus is one of the most common Aspergillus species causing disease in individual animals but it rarely affects deer species. We report a case of A. fumigatus infection causing mycotic pneumonia and hypertrophic osteopathy in a roe deer ( Capreolus capreolus).

Disseminated Conidiobolus incongruus in a dog: A case report and literature review

Conidiobolomycosis is a rare fungal disease of both humans and animals, occurring mainly in tropical and subtropical climates. We describe a disseminated fungal infection in a young, apparently immunocompetent dog who initially presented for antibiotic resistant pneumonia. Histopathology and mycology identified a Conidiobolus sp., further confirmed as Conidiobolus incongruus through DNA sequencing of D1/D2 regions. This is the first report of this species causing disease in dogs and the fifth reported infection in animals.

Human Fungal Pathogens of Mucorales and Entomophthorales

In recent years, we have seen an increase in the number of immunocompromised cohorts as a result of infections and/or medical conditions, which has resulted in an increased incidence of fungal infections. Although rare, the incidence of infections caused by fungi belonging to basal fungal lineages is also continuously increasing. Basal fungal lineages diverged at an early point during the evolution of the fungal lineage, in which, in a simplified four-phylum fungal kingdom, Zygomycota and Chytridiomycota belong to the basal fungi, distinguishing them from Ascomycota and Basidiomycota. Currently there are no known human infections caused by fungi in Chytridiomycota; only Zygomycotan fungi are known to infect humans. Hence, infections caused by zygomycetes have been called zygomycosis, and the term "zygomycosis" is often used as a synonym for "mucormycosis." In the four-phylum fungal kingdom system, Zygomycota is classified mainly based on morphology, including the ability to form coenocytic (aseptated) hyphae and zygospores (sexual spores). In the Zygomycota, there are 10 known orders, two of which, the Mucorales and Entomophthorales, contain species that can infect humans, and the infection has historically been known as zygomycosis. However, recent multilocus sequence typing analyses (the fungal tree of life [AFTOL] project) revealed that the Zygomycota forms not a monophyletic clade but instead a polyphyletic clade, whereas Ascomycota and Basidiomycota are monophyletic. Thus, the term "zygomycosis" needed to be further specified, resulting in the terms "mucormycosis" and "entomophthoramycosis." This review covers these two different types of fungal infections.

Hypertrophic osteopathy associated with a renal adenoma in a cat

Hypertrophic osteopathy is a hyperostotic syndrome of the appendicular skeleton that is most commonly associated with intrathoracic neoplasia or inflammation. The condition is rarely associated with intra-abdominal lesions. The majority of cases have occurred in dogs and human beings, with fewer cases reported in cats, horses, and other species. A 15-year-old male neutered Domestic Shorthair cat presented for swollen limbs and difficulty in ambulation. Radiographs and gross postmortem revealed severe periosteal hyperostosis of the diaphysis and metaphysis of all 4 limbs, including the humerus, radius, ulna, carpi, metacarpi, femur, tibia, tarsi, metatarsi, and phalanges. The axial skeleton was spared. Hyperostotic lesions were characterized microscopically by lamellar bony trabeculae separated by adipocytes and scant hematopoietic tissue. In several areas, fibrovascular connective tissue, woven bone, and islands of cartilage were also present. A 2.5 cm × 2.5 cm perirenal neoplasm compressed the left kidney and adrenal gland. This mass consisted of well-differentiated tubules of cuboidal epithelial cells and was most consistent with a renal tubular adenoma, because mitotic figures were rare, and no distant metastases were found. Thoracic pathology was absent. Hyperostosis was consistent with hypertrophic osteopathy secondary to the renal adenoma. The pathogenesis of hypertrophic osteopathy is uncertain, but predominant theories point to increased peripheral circulation and angiogenesis as a key initiating event. Recent literature highlights the potential role of vascular endothelial growth factor and platelet-derived growth factor in the human condition. The mechanism by which this renal adenoma caused hypertrophic osteopathy is unknown.

Molecular Characterization of Ovine Zygomycosis in Central Western Brazil

Zygomycosis is an important granulomatous disease that affects humans and animals, particularly sheep in tropical regions. Rhinofacial and nasopharyngeal zygomycosis were described in sheep in association with Conidiobolus spp. The present study characterized 5 samples of Conidiobolus isolated from 3 herds with clinical disease in Mato Grosso State, Brazil. The clinical and pathological findings were similar to nasopharyngeal zygomycosis. Based on morphological features, isolates were classified as Conidiobolus spp., and molecular phylogenetic analyses based on 18S ribosomal DNA grouped all isolates in a Conidiobolus lamprauges cluster. The current report describes the molecular characterization of ovine nasopharyngeal zygomycosis associated with C. lamprauges.

Morphologic and phylogenetic characterization of Conidiobolus lamprauges recovered from infected sheep

Conidiobolus lamprauges, a soil and plant entomophthoralean fungus, has been reported only in a horse and, more recently, in sheep with rhinopharyngeal entomophthoramycosis. Thus, little information is available to enable proper identification of this pathogen and its differentiation from other saprotrophic and pathogenic Conidiobolus species. Using classical mycological tools and molecular methodologies, we report for the first time the taxonomic and phylogenetic description of three C. lamprauges isolates recovered from sheep with rhinopharyngeal entomophthoramycosis. The distinctive clinical and pathological features of C. lamprauges are compared with those of other Conidiobolus spp. affecting sheep, as well as with those of the stramenopilan ovine agent Pythium insidiosum. The comparative morphological attributes of Conidiobolus spp. are also diagramed; along with the sequence data generated, they should assist laboratories in the identification of these uncommon species.