Medical Microbiology

304 4 BacteriaasHumanPathogens

Apenicillinorcephalosporinisrecommendedfortherapy.Sourcesofinfec-

tionincludedomesticanimals(dogs,cats,birds,guineapigs)andlivestock

(cattle,sheep,goats,pigs).

Gram-NegativeRodBacteriawithLowPathogenicPotential......

ThebacterialspecieslistedinTable4. 10 aretypicalopportuniststhatocca-

sionallycauseinfectionsinpersonswithdefectivespecificornonspecificim-

munedefenses.Whentheyareisolatedfrominfectivematerial,theirpatho-

logicalsignificanceisinmostcasesdifficulttointerpret.

Table4. 10 OverviewofGram-NegativeRodBacteriawithLowPathogenic

Potential

Bacterialspecies Mostimportantcharacteristics

HACEKgroup

• Hemophilusaphrophilus Endocarditis,cerebralabscesses


• Actinobacillusactino-
  mycetemcomitans

Partofnormaloralcavityflora.Nonmotile,slender

rods;microaerophilic;coloniesonbloodagarwith

“starfish”appearance.Accompanyingbacteriumin

approx. 25 %oforal-cervicofacialactinomycoses.

PenicillinGresistance.Alsoapathogeninendocarditis.

• Cardiobacteriumhominis Nonmotile;pleomorphic.Normalfloraoftherespira-
  torytract.Culturingonbloodagarin 5 %CO 2 at 358 C
  for 4 days.Endocarditis.Occasionallyobservedas
  componentofmixedflorainfacialpurulentinfections.


• Eikenellacorrodens Nonmotile,coccoid.Normalfloraofrespiratoryand
  intestinaltracts.Cultures,onbloodagar,showcorro-
  sionoftheagarsurface.
  Abscesses,woundinfections,peritonitis,empyemas,
  septicarthritis,oftenaspartofamixedflora.Also
  reportsofendocarditisandmeningitis.


• Kingellakingae Normalfloraoftheupperrespiratorytract.Rarecases
  ofendocarditis,arthritis,osteomyelitis.

4

Kayser, Medical Microbiology © 2005 Thieme