Medical Microbiology

Chlamydia 337

Culture.Chlamydiaeexploitenergymetabolismprocessesintheirhostcells

thattheythemselvesarelacking(ATPsynthesis).Forthisreason,theycan

onlybegrowninspecialcellcultures,intheyolksacsofembryonated

heneggs,orinexperimentalanimals.

Chlamydiapsittaci(Ornithosis,Psittacosis)

Pathogenesisandclinicalpicture.ThenaturalhostsofC.psittaciarebirds.

Thisspeciescausesinfectionsoftherespiratoryorgans,theintestinaltract,

thegenitaltract,andtheconjunctivaofparrotsandotherbirds.Humansare

infectedbyinhalationofdust(frombirdexcrements)containingthepatho-

gens,morerarelybyinhalationofinfectiousaerosols.

Afteranincubationperiodofonetothreeweeks,ornithosispresentswith

fever,headache,andapneumoniathatoftentakesanatypicalclinicalcourse.

Theinfectionmay,however,alsoshownomorethanthesymptomsofa

commoncold,orevenremainclinicallysilent.Infectedpersonsarenotusual-

lysourcesofinfection.

Diagnosis.Thepathogencanbegrownfromsputuminspecialcellcultures.

Directdetectioninthecultureisdifficultandonlypossibleinspecially

equippedlaboratories.Thecomplementbindingreactioncanbeusedto

identifyantibodiestoagenericantigencommontoallchlamydiae,sothat

ReproductionCycleofChlamydiae

0 6 12 18 24 30 36 42 48

Hours after infection

a b c d e f

Fig.4. 27 Twochlamydialstages:elementarybodyandinitialbody.

aAttachmentofelementarybodytocellmembrane.

bEndocytosis.

cTransformationofelementarybodyintoinitialbodyinsidetheendosome.

dReproductionofinitialbodiesbytransversefission.

eTransformationofsomeinitialbodiesbackintoelementarybodies.

fLysisofinclusionvesicleandcell,releaseofinitialandelementarybodies.

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Kayser, Medical Microbiology © 2005 Thieme