Cryptococcus neoformans

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Cryptococcus neoformans

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Cryptococcus neoformans

  1. 1. CRYPTOCOCCUS NEOFORMANS Dr.T.V.Rao MDDR.T.V.RAO MD 1
  2. 2. CRYPTOCOCCOSISChronic, subacute to acute pulmonary, systemic ormeningitic disease, initiated by the inhalation of thefungus. Primary pulmonary infections have nodiagnostic symptoms and are usually subclinical. Ondissemination, the fungus usually shows apredilection for the central nervous system, howeverskin, bones and other visceral organs may alsobecome involved.Distribution: World-wide.Aetiological Agent: Cryptococcus neoformans.
  3. 3. CRYPTOCOCCUS NEOFORMANS• A Capsulated yeast– A true yeast..• A sporadic diseasein the past.• Most commoninfection in AIDSpatients.DR.T.V.RAO MD 3
  4. 4. MORPHOLOGY• A true yeast• Round 4 – 10 microns• Surrounded by Mucopolysaccharide capsule.• Thick in vivo• Negative staining with India Ink and Nigrosin• 60% of the infected prove positive by India Ink preparation on examination of CSF• KoH preparations in Sputum and other tissues,• PAS and Mucicaramine staining helps confirmation. 4 DR.T.V.RAO MD
  5. 5. AS SEEN IN INDIA INK PREPARATION 5DR.T.V.RAO MD
  6. 6. CULTURING•CSF -Culturing on Sabouraudsagar, and incubated at 37 0 c forup to 3 weeks•Cultures appear as Creamy,white, yellow Brown colored Simple urease test helps inconfirming the isolate. DR.T.V.RAO MD 6
  7. 7. CRYPTOCOCCUS NEOFORMANS SEROTYPES• A true yeast• 4 serotypes - A,B,C,D• A and D - C.neofromans var neoformans• B and C - C.neoformans var gatti.• Many infections are caused by C.neofromans var neoformans.Found in wild/Domesticated birds.Pigeons carry C.neofromans,Birds do not get infected. 7 DR.T.V.RAO MD
  8. 8. CRYPTOCOCCUS NEOFORMANS Cryptococus neoformans var grubii var gatti var enoformans (now C.gatti)
  9. 9. SEROTYPES - CRYPTOCOCCUS NEOFORMANSSerotypeA – 80% clinical casesB – tropical, subtropical – S. California, Hawaii, Brazil, Australia, SE AsiaC – rareD – Europe – Denmark, Germany, Italy, France, Switzerland
  10. 10. PIGEONS AND RED RIVER GUM TRESS HARBORS THE CRYPTOCOCCUS IN NATURE 10DR.T.V.RAO MD
  11. 11. LIFE CYCLE OF C.NEOFROMANS 11DR.T.V.RAO MD
  12. 12. PATHOGENESIS• Enters through lungs - inhalation of Basidiospores of C neoformans• Enters deep into lungs, Men acquires more infections, and women less infected.• Self limiting in most cases,• Pulmonary infections can occur.• Present as discrete nodules - Cryptococcoma. 12 DR.T.V.RAO MD
  13. 13. PATHOGENESIS• Can infect normal humans• Abnormalities of T lymphocyte function aggravates, the clinical manifestations.• In AIDS 3- 20% develop Cryptococcosis.• Present with Chronic meningitis , Meningo encephalitis• Manifest with – head ache low grade fever,• Visual abnormalities ,Coma – fatal• Treatment reduces the morbidity and cure in non immune suppressed expected. 13 DR.T.V.RAO MD
  14. 14. PATHOGENESIS• Can manifest with involvement of ,Skin, mucosa,organs,Bones,and as Disseminated form. Can mimic like Tuberculosis , 14DR.T.V.RAO MD
  15. 15. CLINICAL MANIFESTATIONSLung- Portal of entry- asymptomatic (1/3)  life threatening pneumonia (ARDS)- Endobronchial colonization  underlying chronic lung disease- Single pulmonary nodule- Symptomatic – acute, sub acute
  16. 16. CLINICAL MANIFESTATIONSCNS- Sub acute meningitis or meningo-encephalitis- Headache, fever, cranial nerve palsies, lethargy, coma- Subacute (days)  monthsHIV- Higher yeast burden-  incidence raised intracranial pressure- Often disseminated- Immune reconstitution disease
  17. 17. CLINICAL MANIFESTATIONSCNS- Subacute meningitis or meningo-encephalitis- Headache, fever, cranial nerve palsies, lethargy, coma- Subacute (days)  monthsHIV- Higher yeast burden-  incidence raised intracranial pressure- Often disseminated- Immune reconstitution disease
  18. 18. LABORATORY DIAGNOSIS.• CSF Microscopic observation under India Ink preparation• Direct microscopy - Gram staining• Cultures on Sabouraud dextrose agar,• Serological tests for detection of Capsular antigen• CSF findings mimic like Tuberculosis• IN CSF - latex test for detection of Antigen• Blood cultures,• ELISA 18 DR.T.V.RAO MD
  19. 19. IDENTIFICATION OF C.ALBICANS• Mixed culture of C. neoformans and C. albicans on bird seed agar (Guizotia seeds) showing the distinctive brown colonies of C. neoformans, due to the selective absorption of pigment from the media, compared to the white colonies of C. albicans.DR.T.V.RAO MD 19
  20. 20. 1MICROSCOPIC MORPHOLOGY OF C. NEOFORMANS SHOWING ENCAPSULATED BUDDING, YEAST CELLS. NO PSEUDO HYPHAE ARE PRODUCED . 0
  21. 21. C. NEOFORMANS ON SABOURAUDS DEXTROSE AGAR • C. neoformans on Sabourauds dextrose agar showing typical dark cream coloured, smooth, moist, shining and mucoid colonies.DR.T.V.RAO MD 21
  22. 22. TREATMENT• Immune competent - Fuconazole,Itraconazole• Immune Deficient – Amphotericin B Flu cytosine AIDS patients are not totally cured , Relapses are frequent with fatal outcome. Rapid resistance with Fluconazole. Avoid contact with Birds 22DR.T.V.RAO MD
  23. 23. PREVENTION• Fluconazole prophylaxis• Active immunization- cryptococcal GXM-tetanus toxoid conjugate vaccine- in animal models, no human trials• Monoclonal antibodies- would require repeated injections• Avoid high risk environments
  24. 24. EPIDEMIOLOGY• HIV• Lymphoproliferative disorders• Sarcoidosis• Corticosteroids• Hyper IgM or IgE syndrome• Monoclonal antibodies (infliximab)• SLE• CD4 T-cell lymphoma (idiopathic)• Diabetes• Organ transplant• Peritoneal dialysis• Cirrhosis• 20% without HIV have no underlying comorbidity
  25. 25. • Created by Dr.T.V.Rao MD for Medical and Paramedical students in Developing World • Email • doctortvrao@gmail.comDR.T.V.RAO MD 25

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