Medical Microbiology

(seeFig.6.7c).AmplificationofspecificDNAsequencesusingthePCRhas

recentlycometotheforeasausefulmoleculardetectionmethod.

Therapy.Acutepneumocystosisistreatedwithcotrimoxazole(oralorpar-

enteral)orpentamidine(parenteral)oracombinationofbothofthese

anti-infectiveagents.Pentamidinecanalsobeappliedinaerosolformto

reducethesideeffects.

SubcutaneousMycoses

Fungithatcauseclassicsubcutaneousmycosesgrowinthesoilandondying

plants.Theypenetratethroughskininjuriesintothesubcutaneousconnec-

tivetissue,wheretheycauselocal,chronic,granulomatousinfections.These

infectionsareseenmainlyinthetropicsandsubtropics.

SporotrichosisiscausedbySporothrixschenckii,adimorphicfungusthat

growsasyeastcellsinhosttissues.Sporotrichosisischaracterizedbyan

ulcerousprimarylesion,usuallyonanextremity,andmultiplenodules

andabscessesalongthelymphaticvessels.

Chromomycosis(alsochromoblastomycosis)canbecausedbyanumberof

speciesofblackmolds.Thenomenclatureofthesepathogensisnotfirmly

established.Weeksormonthsafterthesporespenetrateintoahost,wartlike,

ulcerating,granulomatouslesionsdevelop,usuallyonthelowerextremities.

Madurafootormycetomacanbecausedbyawidevarietyoffungiaswellas

byfilamentousbacteria(Nocardiasp.,Actinomaduramadurae,Streptomyces

somaliensis).PotentialfungalcontributorsincludeMadurellasp.,Pseudoal-

lescheriaboydii,andAspergillussp.Theclinicalpictureischaracterizedby

subcutaneousabscesses,usuallyonthefeetorhands.Theabscessescan

spreadintothemusculatureandevenintothebones.Fistulaeareoften

formed.

CutaneousMycoses

Dermatophytes(Dermatomycosesor

Dermatophytoses)

Dermatophytesarefungithatinfecttissuescontainingplentyofkeratin(skin,

hair,nails).

372 6 FungiasHumanPathogens

6

Kayser, Medical Microbiology © 2005 Thieme