Medical Microbiology

356 5 GeneralMycology

cificimmunity,especiallythecellulartype.Theroleofhumoralimmunityin

specificimmunedefenseissecondary.

Diagnosis

Theprimaryconcernhereisidentificationofthepathogen.

&Microscopy.Nativepreparation:brieflyheatmaterialundercoverslip

with 10 %KOH.Stainedpreparation:stainwithmethyleneblue,lactophenol

blue,periodicacid-Schiff(PAS),ink,etc.

&Culturing.Thisispossibleonuniversalandselectivemediums.Sabour-

auddextroseagarcancontainselectiveagents(e.g.,chloramphenicolandcy-

cloheximide),thismediumhasanacidpHof5.6.Themainidentifyingstruc-

turesaremorphological,inparticulartheasexualand,ifpresent,sexualre-

productivestructures.Biochemicaltestsareusedmainlytoidentifyyeasts

andaregenerallynotasimportantinmycologyastheyareinbacteriology.

&Serology.Bytheidentificationofantibodiestospecialfungalantigensin

patient’sserum.TheInterpretationofserologicalfindingsisquitedifficultin

fungalinfections.

&Antigendetection.Byfindingofspecificantigensinthediagnosticma-

terialbydirectmeansusingknownantibodies,possibleinsomefungalin-

fections(e.g.,cryptococcosis).

&Cutaneoustest.Cutaneous(allergy)testswithspecificfungalantigens

canbeusefulindiagnosinganumberoffungalinfections.

&Nucleicaciddetection.Combinedwithamplification,suchtestsareuse-

fulforrapiddetectionofmycoticdiseasesinimmunocompromisedpatients.

Therapy

Alimitednumberofanti-infectiveagentsareavailableforspecifictreatment

offungalinfections:

&Polyenes.Theseagentsbindtomembranesterolsanddestroythemem-

branestructure:

— AmphotericinB.UsedInsystemicmycoses.Fungicidalactivitywithfre-

quentsideeffects.Thereareconventionalgalenicformand(new)various

lipidforms.

— Nystatin,natamycin.Onlyfortopicaluseinmucosalmycoses.

5

Kayser, Medical Microbiology © 2005 Thieme