Mycology IntroductionStudent LabDivision of Medical TechnologyCarol Larson MSEd, MT(ASCP)

MycosesSuperficialSubcutaneousSystemicOpportunistic

Characteristics of fungiEukaryoticGrowth requirementsFormsMoldYeast

AseptateHyphaeSeptate

HyphaeHyalineDematiaceous

MyceliumMass of branching intertwined hyphaeVegetativeAerialFertile

Vegetative typesFavic chandeliersNodular organsRacquet hyphaeSpiral hyphae

ReproductionIdentify fungi by:Morphology of reproductive structures

Spores from vegetative mycelium or aerial fruiting bodies

Asexual ReproductionConidiaConidiophoreArthroconidia

Asexual ReproductionBlastoconidia

PseudohyphaeChlamydoconidiaChlamydospores

Asexual ReproductionMacroconidiaMicroconidiaPhialoconidiaPhialide

Asexual ReproductionAnnelloconidiaAnnellideSporangiosporesSporangiumSporangiophore

Sexual ReproductionPerfect Fungi has a sexual stageFungi Imperfecti no know sexual stage

Spores

Sexual ReproductionAscosporesAscusAscocarpBasidiosporesZygospores

In review Mycoses fungal diseasesCharacteristics of fungiGrowth requirementsForms (mold, yeast)StructuresReproductionAsexualSexual

Fungal Culture ProcessSpecimen collection and transportationDirect examination of specimenSelection and inoculation of mediaEvaluation of fungal growthSerological testingAntifungal susceptibility testing

Specimen CollectionSpecimen typesCollect from area most likely infectedUse sterile techniqueKeep specimen moistLabel container properlyTransport right awayProcess right away

Direct ExaminationProvides preliminary reportGuides MD in treatment of patientObserve yeast phase of dimorphicGives clues to id causative agentInoculate special mediaMay require more than one direct examination method

Direct ExaminationSaline wet mountLactophenol cotton blue wet mount10% KOH preparationGram stainAcid fast stainIndia ink stain

Direct ExaminationCalcofluor white stainWrights stainGomori Methenamine Silver stainPeriodic Acid Schiff stain

Specimen ProcessingSafetyTube media preferred over plate mediaWork in safety hoodWear gloves and lab coatAutoclave specimens and mediaDisinfect work area daily

Specimen ProcessingPrimary isolation mediaGoal: isolate potential pathogensUse non-selective and selective mediaProper ingredientsIncubation temperatureIncubation timeIncubation atmosphere

Non-selective MediaSabouraud dextrose agarBrain heart infusion (BHI) with/without 5% blood and 1% glucose

Selective MediaMycosel agarInhibitory mold agarDermatophyte test medium

Subculture / Identification MediaNeutral Sabouraud dextrose agar (Emmons)Cornmeal-Tween 80 agarNiger seed agar (Birdseed agar)Tween 80 / Oxgall / caffeic acid agarPotato dextrose agar

Examination of Culture GrowthPotential pathogensSlow growersGrowth on MycoselColor: dull buff, brown, mousy grayDimorphic

Examination of Culture GrowthGrowth rateRapid growers: 1-5 daysIntermediate growers: 6-10 daysSlow growers: >10 days

Colony Morphology AppearanceRugoseUmbonateVerrucoseFlat

Colony Morphology TextureCottonyGlabrousGranularVelvety

Colony Morphology PigmentationSurfaceReverse

Microscopic MorphologyDefinitive means of identificationEvaluate:ShapeMethod of productionArrangement of conidia/sporesSize and color of hyphae

Microscopic TechniquesTease mountScotch tape preparationSlide culture

Serological DiagnosisImmunodiffusionComplement fixationEIALatex agglutination

Antifungal SusceptibilityDetermine appropriatenessStandardization of testingMethodsPredictability in vivoAntifungal agents

In Summary Specimen collection and transportSpecimen processing and cultureDirect examination of specimenExamination of cultureSerological testingAntifungal susceptibility