Vergleich der genetischen und biochemisch-phänotypischen Eigenschaften von ausgewählten Stämmen der fakultativ pathogenen Spezies Actinobacillus actinomycetemcomitans

The optional pathogenious microorganism Actinobacillus actinomycetemcomitans belongs to the physiological oral bacteria population of the human oral cavity and the oral cavity of other mammals. Actinobacillus actinomycetemcomitans can be found in humans with periodontal diseases and those who have healthy periodontal conditions. Because of a lot of pathogenetical mechanisms Actinobacillus actinomycetemcomitans has the ability to initiate destructive periodontal diseases such as localized aggressive periodontitis, but the organism is also occasionally responsible for non-oral infections including endocarditis, septicemia, sinusitis, chronical bronchitis, pneumonia, osteomyelitis, urinary tract infections and different abscesses. Actinobacillus actinomycetemcomitans is very demanding with regard to cultural conditions and thats why its not always easy to diagnose this organism. Actinobacillus actinomycetemcomtans is a small nonmotile gram-negative coccobacillus that grows singly, in pairs or in small clumps and is variously described as fakultatively anaerobic, microaerophilic and capnophilic. 34 strains of Actinobacillus actinomycetemcomitans which were stored in the institute of medical microbiology and hospital hygiene in Marburg were analyzed. The aim was to find predictive evidence of virulence/pathogenicity of Actinobacillus actinomycetemcomitans by means of genomical marks in microbiological diagnostics.The strains were analyzed by using two different molecularbiological methods and one classical phenotypical characterization. Neither the results of DNA-DNA hybridization by means of the optical renaturation method nor the results of DNA-sequenzing reflected the differences of the chronical and acute infections caused by the strains. By determining the biochemical characteristics by means of the "Bunte Reihe" and commercial quick-test-systems was the aim to find out, if phenotypical characteristics are reliable marks for taxonomical tests and if special characteristics and characteristical phenotypical combinations give indication to the pathogenetic potential of certain isolates. In addition the phenotypical results were compared with the genetical results.