Medical Microbiology

Corynebacterium,Actinomyces,OtherGram-PositiveRodBacteria 259

pathogens.Genuineactinomycosesareactuallyalwayspolymicrobial.The

mixedflorafoundincludesmainlytheanaerobesoftheoralcavity.Actino-

bacillusactinomycetemcomitansisfrequentlyisolatedalongwithvariousspe-

ciesofBacteroidaceae.Facultativeanaerobessuchasstaphylococci,strepto-

cocci,andEnterobacteriaceaeare,however,alsofoundamongthecontribut-

ingflora.

&Cervicofacialactinomycosis.Thisisthemostfrequentformofactinomy-

cetesinfection(> 90 %).Theabscessesarehardandtumorlikeatfirst,then

theynecrotize.Theymayalsobreakthroughtothedermalsurfacetocreate

fistulae.

&Thoracicactinomycosis.Thisrareformresultsfromaspirationofsaliva;

sometimesthistypealsodevelopsfromanactinomycosisinthethroatorhe-

matogenousspread.

&Abdominalactinomycosis.Thistyperesultsfrominjuriestotheintestine

orfemalegenitals.

&Genitalactinomycosis.Mayresultfromuseofintrauterinecontraceptive

devices.

&Canaliculitis.Aninflammationofthelacrimalcanaliculicausedbyanyof

severalActinomycesspecies.

&Caries.TheActinomycesspeciesinvolvedincariesdevelopmentareA.vis-

cosus,A.naeslundii,andA.odontolyticus(p. 2 43f.).Apossiblecontributionto

periodontitisisalsounderdiscussion.

Diagnosisinvolvesidentificationofthepathogenbymicroscopyandcultur-

inginpus,fistulasecretion,granulationtissue,orbronchialsecretion.The

samplesmustnotbecontaminatedwithotherpatientflora,inparticular

fromtheoralcavityandmustbetransportedtothelaboratoryinspecial

anaerobecontainers.Microscopicdetectionofbranchedrodssufficesfora

tentativediagnosis.Detectionofmycelialmicrocoloniesonenrichednutrient

mediumsafteronetotwoweeksfurtherconsolidatesthisdiagnosis.Final

identificationbymeansofdirectimmunofluorescence,cellwallanalysis,

andmetabolicanalysisrequiresseveralweeks.

Therapy.Treatmentincludesbothsurgicalandantibioticmeasures.Theanti-

bioticofchoiceisanaminopenicillin.Antibiosisthatalsocoversthecontri-

butingbacterialpathogensisimportant.

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Kayser, Medical Microbiology © 2005 Thieme