ISSN 2398-2942      

Cryptococcus neoformans

icanis
Contributor(s):

Rosanna Marsella

Synonym(s): C. neoformans


Introduction

Classification

Taxonomy

  • Genus: Cryptococcus - a genus of yeast-like fungi. (Strains have been experimentally converted to a mycelial, sexually reproducing phase and given the name Filobasidiella neoformans.)

Active Forms

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Clinical Effects

Epidemiology

Habitat

  • Lives in soil and dust.

Lifecycle

  • Can affect any mammal, but cats are at higher risk for it.
  • No immunosuppression is usually detected in cats with cryptococcosis, eg FeLV, FIV.
  • Pigeons often carry the agent but are rarely affected clinically - temperature too high for growth of agent.

Transmission

  • Respiratory, occasionally percutaneous by direct inoculation of the organism.
  • Non-contagious.

Pathological effects

  • Human infection often associated with pre-existing immunosuppression.
  • Virulence is largely associated with the antiphagocytic and immunosuppressive capsule.
  • Route of infection: usually respiratory, resulting in lesions in nasal cavity or sinuses with possible extension to the brain (involvement of the optic nerve causing blindness), and meninges.
  • Cattle: mastitis, with severe swelling and rarely may spread to lungs. Infection may be introduced during intramammary medication.
  • Horses: nasal passage granulomata.
  • Dogs: granulomata of subcutaneous tissue, with possible central nervous system (CNS) and ocular signs including.
  • Cats: granulomata of subcutaneous tissue, with respiratory signs.
  • Human beings: respiratory disease and meningitis.

Control

Control via chemotherapies

  • Amphotericin B Amphotericin B (used initially for rapid efficacy combined later on with aerodes, eg flucytosine (orally) Flucytosine ).
  • Fluconazole Fluconazole - drug of choice if neurological involvement is present due to excellent penetration in the brain. Used orally at 2.5-5 mg/kg once daily for several months. Dosage should be reduced in patients with compromised renal function.

Control via environment

  • Avoid areas contaminated with pigeon droppings.

Vaccination

  • Not available.

Diagnosis

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Malik R, Speed B R, Kaldor J et al (1999) Serum antibody response to Cryptococcus neoformans in cats, dogs and koalas with and without active infection. Med Mycol 37 (1), 43-51 PubMed.
  • Malik R, Hunt G B, Bellenger C R et al (1999) Intra-abdominal cryptococcosis in two dogs. JSAP 40 (8), 387-391 PubMed.
  • Tiches D, Vite C H, Dayrell-Hart B et al (1998) A case of canine central nervous system cryptococcosis - management with fluconazole. JAAHA 34 (2), 145-151 PubMed.
  • Malik R, McPetrie R, Wigney D I et al (1996) A latex cryptococcal antigen agglutination test for diagnosis and monitoring of therapy for cryptococcosis. Aust Vet J 74 (5), 358-364 PubMed.
  • Malik R, Craig A J, Wigney D I et al (1996) Combination chemotherapy of canine and feline cryptococcosis using subcutaneously administered amphotericin B. Aust Vet J 73 (4), 124-128 PubMed.
  • Malik R, Dill-Macky E, Martin P et al (1995) Cryptococcosis in dogs - a retrospective study of 20 consecutive cases. J Med Vet Mycol 33 (5), 291-297 PubMed.
  • Cook J R, Evinger J V, Wagner L A (1991) Successful combination chemotherapy for canine cryptococcal meningoencephalitis. JAAHA 27 (1), 61-64 VetMedResource.
  • Mason G D, Labato M A, Bachrach A Jr. (1989) Ketoconazole therapy in a dog with systemic cryptococcosis. JAVMA 195 (7), 954-956 PubMed.
  • Hodgin E C, Corstvet R E, Blakewood B W (1987) Cryptococcosis in a pup. JAVMA 191 (6), 697-698 PubMed.
  • Noxon J O, Monroe W E, Chinn D R et al (1986) Ketoconazole treatment in canine and feline cryptococcosis. JAAHA 22 (2), 179-183 VetMedResource.

Can’t find what you’re looking for?

We have an ever growing content library on Vetlexicon so if you ever find we haven't covered something that you need please fill in the form below and let us know!

 
 
 
 

To show you are not a Bot please can you enter the number showing adjacent to this field

 Security code