Lecythophora spp

From Dog
Lecythophora hoffmannii culture on agar[1]

Lecythophora spp are a filamentous fungus which is normally found as a commensal on rotting vegetation[2].

They form adelophialides, but these conidiogenous cells show conspicuous collarettes and colonies usually are pink-salmon to dark brown[3].

Lecythophora are commonly involved in human AIDS-associated infections, often with a fatal outcome, following peritonitis, endocarditis, endophthalmitis and keratitis[4]. As a species, they are poorly differentiated morphologically, are difficult to identify, and may be confused with poorly sporulating Fusarium spp.

Dogs are thought to become infected from ingesting or inhaling conidial spores while foraging, through skin wounds or when eating small amphibians and reptiles.

Lecythophora are an opportunistic pathogen that causes infections characterized by progressive granulomatous lesions in the subcutaneous tissues as well as disseminated visceral infections.

Species which are pathogenic to dogs include:

  • Lecythophora hoffmannii
  • Lecythophora mutabilis

In dogs, chronic diarrhea is usually reported as a symptom of infection, although lymphadenopathy and osteomyelitis have been reported[5].

Similar symptoms and histology are observed with Pythium insidiosum, Basidiobolus spp and Cokeromyces spp, making them difficult to distinguish from one another.

Diagnosis can be ascertained by microscopic identification of the fungus or by PCR assay speciation. Lymph nodes characteristically contain PAS positive fungal elements and portions of tissue culture produce mycelial fungal growth.

Treatment has been effective with long-term azole therapy, specifically ketoconazole or itraconazole.

References

  1. Medical Mycology
  2. Domsch, KH et al (1980) Compendium of soil fungi. Volume 1. Academic Press, London, UK
  3. De Hoog G et al (2000) Atlas of clinical fungi, 2nd ed. Centraalbureau voor Schimmelcultures, Utrecht, Netherlands
  4. Proia LA et al (2004) Phialemonium: an emerging mold pathogen that caused 4 cases of hemodialysis-associated endovascular infection. Clin Infect Dis 39:373–379
  5. Sakaeyama S et al (2007) Lecythophora hoffmannii isolated from a case of canine osteomyelitis in Japan. Med Mycol 45(3):267-272