Systemic mycoses

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  • 1. SYSTEMICMYCOSESWednesday, January 11, 2012

2. SUMMARY OF DEEP MYCOSES DISEASES AND SAPROPHYTIC PHASE PARASITIC PHASEETIOLOGIC AGENTBlastomycosisbudding yeast with septate mycelium; conidia areBlastomyces dermatitidisbroad base budpyriform, globose or doublecolonies are white or beige,fluffly or glaborousHistoplasmosis septate mycelia microconidia; small single buddedHistoplasma capsulatumtuberculate macroconidia yeastcolonies are white and buffCoccidioidomycosis septate mycelium fragment tospherule (10-20 u) withCoccidiodes arthroconidia; colonies are endosporesimmitis buff or white and mothParacoccidiodomycosis similar to B. dermatitidis large multiple buddingParacoccidioides yeastWednesday, January 11, 2012 3. CHARACTERISTICS TO REMEMBERMonomorphicDimorphicNo change in form/state Change in form inin response to stimulus response to stimulus likelike temperature. temperature. ExampleExample, yeast at 25 C yeast at 37 C andand 37 C mycelium at 25 CExamples: Mycelium =Examples: Histoplasma capsulatum;Blastomyces dermatitidis;Aspergillus species; YeastParacoccidiodes brasiliensis;= Cryptococcus speciesCoccidiodes immitisWednesday, January 11, 2012 4. FACTORS AFFECTING DIMORPHISMTemperatureOxidation-reduction potentialAvailability of sulfhydril groupsCO2 tensionWednesday, January 11, 2012 5. Histoplasma capsulatumDimorphicMycelial phase: 25 CMacroconidia(8-14m)Microconidia(2-4m)Wednesday, January 11, 2012 6. Histoplasma capsulatumAt 37C or at bodytemperature =budding yeast 2-3 x3-4 mFound predominantlyin histiocytesWednesday, January 11, 2012 7. LIFE CYCLEsoil with high nitrogen content, associated with theguano of bats and starlingsrotting guano mixed with soil & feathers of the birdsopen environment, soil is nitrogen rich with a rainfallof 35-50 inches and 67-87% relative humiditycaves, the main habitat of bats, which are thereservoir of Histoplasma capsulatumWednesday, January 11, 2012 8. LIFE CYCLEWednesday, January 11, 2012 9. CLASSIFICATION OF HISTOPLASMOSIS TYPE OF SPECIFICCOMMENTS INFECTIONDISORDER Asymptomatic or Occurs with mild like u normal exposure illness Acute pulmonary Occurs withNormal Hosts histoplasmosisheavy exposure Pericarditis, Rare mediastinal complications brosisWednesday, January 11, 2012 10. CLASSIFICATION OF HISTOPLASMOSIS TYPE OF SPECIFICCOMMENTS INFECTIONDISORDER Occurs in Disseminated individuals who histoplasmosis have an immuneOpportunistic defectInfection Occurs in Chronic individuals who pulmonary have a structural histoplasmosis defectWednesday, January 11, 2012 11. CLASSIFICATION OF HISTOPLASMOSIS TYPE OF SPECIFICCOMMENTS INFECTIONDISORDER Occurs in Disseminated individuals who histoplasmosis have an immuneOpportunistic defectInfection Occurs in Chronic individuals who pulmonary have a structural histoplasmosis defectWednesday, January 11, 2012 12. CLINICAL FORMS & SYMPTOMS TYPE OF INFECTIONSPECIFIC DISORDER Asymptomatic or u-like syndrome Primary acute Chest pain, shortness of breath and hoarseness Radiologically, discrete lung lesion may or may not develop Large pulmonary lesions develop Chronic cavitary lesions may exist in a relative quiescent state Often mistaken for tuberculosis Only small percentage progress into this clinical forms Disease of reticuloendothelial system in which organs infection may Severe disseminateddevelop In massive dissemination, it could be fatalWednesday, January 11, 2012 13. HISTOPLASMOSISWednesday, January 11, 2012 14. LABORATORY DIAGNOSISDirect Examination:KOH; Wright/GiemsaCulture: SDA; Smith andGoodman (forcontaminated specimen);Yeast Extract = place theCM in a plastic bagWednesday, January 11, 2012 15. LABORATORY DIAGNOSISSkin test withhistoplasmin AgCF testImmunodiffusiontestWednesday, January 11, 2012 16. TREATMENT & PREVENTIONAmphotericin B fordisseminated infectionItraconazole forimmunocompromisedpatients Cleaning of bat droppingsWednesday, January 11, 2012 17. Blastomyces dermatitidis2 phases: asexual & sexualBlastomyces dermatitidis(asexual phase)Ajellomyces dermatitidis(sexual phase)Dimorphic fungusWednesday, January 11, 2012 18. Blastomyces dermatitidis MYCELIAL FORMThe mycelial phase at 25 C showed typicalpyriform microconidia , which are about 2-4microns in diameter.YEAST FORMAt 37 C and at body temperature, thisorganism is a yeast 8-15 microns in diameter.Buds are produced singly and are attached toparent cell by broad base.Wednesday, January 11, 2012 19. LIFE CYCLE The mode of transmission: inhalation of the spores or the microconidia Natural habitat: remains an enigma Favors environment with high nitrogen content, acid pH, abundant moisture, and perhaps enriched with animal excretaWednesday, January 11, 2012 20. LIFE CYCLEWednesday, January 11, 2012 21. BLASTOMYCOSIS Chicago Disease = Gilchrists disease = North American BlastomycosisWednesday, January 11, 2012 22. CLINICAL FORMSSYMPTOMSPulmonary Fever, cough and hoarseness Productive cough, fever and weight lossafter several months Radiographically resembles tuberculosisSystemic Extension of pulmonary form Common sites of involvement are liverand spleen Granulomatous lesions are presentCutaneous Indicates systemic disease May result from direct inoculation fromthe soilWednesday, January 11, 2012 23. TESTS IMPORTANT FEATURES1. Direct Microscopic 20% KOH specimen is sputum for pulmonary formand skin for cutaneous form Biopsy material can also be used Look for the presence of broad basedbuds2. CultureSaborauds, Mycosel or Mycobiotic Agar Fluffy, whitish brown fungus with pyriformspores Culture is not routinely done3. Skin TestBlastomycin Has a tendency of high cross reactivity Little diagnostic valueWednesday, January 11, 2012 24. Wednesday, January 11, 2012 25. TREATMENT & PREVENTIONAmphotericin B has been used but with erratic results 2-hydroxystilbamidine Ketoconazole, less nephrotoxicity Prevent fomite inhalation in endemic areaWednesday, January 11, 2012 26. Coccidioides immitisAmphotericin B has been used but with erratic results Asexual phase: Coccidiodes immitis Sexual phase: not known MYCELIAL STAGE (25C) septate hyphae mature in a manner such that alternate cells develop into arthroconidia being separated by vacuolized cellsarthroconidia separate readily and have a barrel shapeappearanceWednesday, January 11, 2012 27. Coccidioides immitisWednesday, January 11, 2012 28. Coccidioides immitisYEAST FORM In tissue and at body temperature:Develops into spherules (sporangia;10-60m) lled with endospores (2-5m)Wednesday, January 11, 2012 29. LIFE CYCLEWednesday, January 11, 2012 30. COCCIDIOMYCOSISPosadas Disease = San Joaquin Valley Fever = Desert RheumatismTREATMENT & PREVENTIONGenerally difcult to manageregardless of drug useAmphotericin B is the drug of choiceItraconazole and uconazole havebeen tried with little successPrevent spores inhalationWednesday, January 11, 2012 31. CLINICAL FORMSSYMPTOMSPrimary Pulmonary Occurs 7-28 days after inhalation ofsingle spore Positive skin test Flu-like fever, malaise and cough 10% develop erythrema nodosum orerythrema multiformeBenign Form Precipitin and complement fixation titersappear Development of well defined lungcavitation Exist for years and could be unnoticedDisseminated Form 1 in 500 patients progressed into thisstate Fungi spreads into various organs Prognosis is graveWednesday, January 11, 2012 32. TESTS IMPORTANT FEATURES1. Direct Microscopic 10-20% KOH sputum, tissue or skin are used as specimen look for the presence of spherules2. CultureSaborauds medium with or without antibiotics room temperature, white fluffy fungus arthrospores are dangerous to work with Never try the organism in the petri dish but alwayson the bottle or test tube Examine on the 3rd or 4th day, but must killorganisms with formalin before attempting tomake an LPCB mount Can prepare exoantigen3. Others Skin test conversion back to skin test positive (anergy) is anindication of grave prognosisWednesday, January 11, 2012 33. Wednesday, January 11, 2012 34. Paracoccidioimycosis brasiliensisDimorphicMycelial stage (25C): notypical sporulationYeast stage (37C): withseveral budding cellsattached to the parent cell,some in a marinerswheel arrangementabout 2-30mWednesday, January 11, 2012 35. LIFE CYCLETransmitted by inhalation of the spores Restricted to South and Central America Isolated in acidic soil and its growth requires increased humidity natural habitat remains to be elucidatedWednesday, January 11, 2012 36. Wednesday, January 11, 2012 37. PARACOCCIDIODOMYCOSISSouth American Blastomycosis = Lutz-Splendore-Almeidas DiseaseA chronic granulomatous disease of skin,mucous membranes, lymph nodes and internalorgansCentral and South America more specically inBrazilWednesday, January 11, 2012 38. PARACOCCIDIODOMYCOSISFemales are as susceptible to infections as males,but the incidence of clinical disease in males isnine times higherPrimary pulmonary disease is often inapparentDisseminated disease often causes ulcerativelesions of the buccal, nasal and occasionallygastrointestinal mucosa.Wednesday, January 11, 2012 39. TESTS IMPORTANT FEATURES1. Direct Microscopic 10-20% KOH 1-2 drops are used demonstration of multiple budding yeast2. CultureSaborauds At room temperature it grows a nonspore forming septate fungusBrain Heart Infusion at 35 C It produces yeast that is seen in tissue3. Others Paracoccidioidin skin test Complement fixation test Immunodiffusion test Dr. Supachai BasitWednesday, January 11, 2012 40. TREATMENT & PREVENTIONAmphotericin BItraconazoleLong term therapy is requiredPrevent inhalation of dust in endemicareaWednesday, January 11, 2012 41. Cryptococcus neoformansMonomorphic:always in yeast formwhether at 25 or at37 C.Unique feature: acidicmucopolysaccharidecapsuleWednesday, January 11, 2012 42. LIFE CYCLEThe etiologic agent of cryptococcosis has beenrecov