Medical Microbiology

morphologicallysimilartooralsoorisvulvovaginitis.Diabetes,pregnancy,

progesteronetherapy,andintensiveantibiotictreatmentthateliminate

thenormalbacterialfloraareamongthepredisposingfactors.Skinismainly

infectedonthemoist,warmpartsofthebody.Candidacanspreadtocause

secondaryinfectionsofthelungs,kidneys,andotherorgans.Candidialen-

docarditisandendophthalmitisareobservedindrugaddicts.Chronicmuco-

cutaneouscandidiasisisobservedasasequeltodamageofthecellularim-

munesystem(Fig.6. 3 ).

Diagnosis.Thisinvolvesmicroscopicexaminationofpreparationsofdifferent

materials,bothnativeandGram-stained.Candidagrowsonmanystandard

nutrientmediums,particularlywellonSabouraudagar.Typicalyeastcolonies

areidentifiedunderthemicroscopeandbasedonspecificmetabolicevidence.

DetectionofCandida-specificantigensinserum(e.g.,freemannan)ispos-

sibleusinganagglutinationreactionwithlatexparticlestowhichmonoclonal

antibodiesarebound.Variousmethodsareusedtoidentifyantibodiesin

deepcandidiasis(agglutination,gelprecipitation,enzymaticimmunoassays,

immunoelectrophoresis).

Therapy.Nystatinandazolescanbeusedintopicaltherapy.Incasesofdeep

candidiasis,amphotericinBisstilltheagentofchoice,oftenadministered

togetherwith5-fluorocytosine.Echinocandins(e.g.,caspofungin)canbe

usedinsevereoropharyngealandesophagealcandidiasis.

Epidemiologyandprevention.Candidainfectionsare,withtheexceptionof

candidiasisinnewbornchildren,endogenousinfections.

Aspergillus(Aspergillosis)

AspergillosesaremostfrequentlycausedbyAspergillusfumigatusandA.fla-

vus.A.niger,A.nidulans,andA.terreusarefoundlessoften.Aspergilliare

ubiquitousinnature.Theyarefoundinlargenumbersonrottingplants.

Morphologyandculture.Aspergillusisrecognizedintissuepreparations,

exudatesandsputumbythefilamentous,septatehyphae,whichareapproxi-

mately 3 – 4 lmwidewithY-shapedbranchings(Fig.6. 4 ).

Aspergillusgrowsrapidly,inmycelialform,onmanyofthemediumscom-

monlyusedinclinicalmicrobiology.Sabouraudagarissuitableforselective

culturing.

Pathogenesisandclinicalpictures.Themainportalofentryforthispatho-

genisthebronchialsystem,buttheorganismcanalsoinvadethebody

throughinjuriesintheskinormucosa.Thefollowinglocalizationsareknown

foraspergilloses:

364 6 FungiasHumanPathogens

6

Kayser, Medical Microbiology © 2005 Thieme