Medical Microbiology

Gram-NegativeAnaerobes 319

Epidemiologyandprevention.Mostinfectionsarisefromthepatient’sown

flora.Exogenousinfectionscanbecontractedfromanimalbites.Following

intestinalsurgery,suitableanti-infectiveagents(seeabove)areadministered

foronetotwodaystopreventinfections.

Table4. 11 OverviewofMedicallySignificantGeneraandSpeciesof

Gram-NegativeAnaerobes

Taxonomy Remarksandclinicalpictures

Bacteroides

B.fragilis

B.distasonis

B.thetaiotaomicron

B.merdae

B.caccae

B.vulgatusandothers

Bacteriaofthenormalintestinalflora;inlargeintestine

> 1011 /gofstool.Thesespeciesarealsoclassifiedun-

derthedesignationBacteroidesfragilisgroup.

Mainlyperitonitis,intraabdominalabscesses,hepatic

abscesses.

Prevotella

P.bivia

P.disiens

P.buccae

P.oralis

P.buccalisandothers

Normalfloraoftheurogenitaltractand/ororophar-

ynx.AlsoknownasthePrevotellaoralisgroup(formerly

Bacteroidesoralisgroup).

Chronicotitismediaandsinusitis,dentalabscesses,

ulceratinggingivostomatitis,infectionsofthefemale

genitaltract,cerebralabscesses.

Prevotella

P.melaninogenica

P.intermediaandothers

Normaloralflora;blackish-brownhematinpigment.

AlsoknownasthePrevotellamelaninogenicagroup.

Aspirationpneumonia,pulmonaryabscesses,pleural

empyema,cerebralabscesses.

Porphyromonas

P.asaccharolytica

P.endodontalis

P.gingivalis,andothers

Normaloralflora.

Dentalabscesses,gingivostomatitis,periodontitis;also

contributetoinfectionsofthelowerrespiratorytract

(seeabove);cerebralabscesses.

Fusobacterium

F.nucleatum

F.necropherum

F.periodonticum

F.sulci(nov.sp.)

F.ulcerans(nov.sp.),

andothers

Rodswithpointedends.Spindleforms.Normaloral

andintestinalflora.

Infectionsintheorofacialarea,lowerrespiratorytract,

andabdomen;Plaut-Vincentangina

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Kayser, Medical Microbiology © 2005 Thieme