Do biofilm formation and interactions with human cells explain the clinical success of Acinetobacter baumannii?
BACKGROUND
The dramatic increase in antibiotic resistance and the recent manifestation in war trauma patients underscore the threat of Acinetobacter baumannii as a nosocomial pathogen. Despite numerous reports documenting its epidemicity, little is known about the pathogenicity of A. baumannii. The aim of this study was to obtain insight into the factors that might explain the clinical success of A. baumannii.


RESULTS
We compared biofilm formation, adherence to and inflammatory cytokine induction by human cells for a large panel of well-described strains of A. baumannii and compared these features to that of other, clinically less relevant Acinetobacter species. Results revealed that biofilm formation and adherence to airway epithelial cells varied widely within the various species, but did not differ among the species. However, airway epithelial cells and cultured human macrophages produced significantly less inflammatory cytokines upon exposure to A. baumannii strains than to strains of A. junii, a species infrequently causing infection.


CONCLUSIONS
The induction of a weak inflammatory response may provide a clue to the persistence of A. baumannii in patients.
de Breij
Anna
A
Department of Infectious Diseases, Leiden University Medical Centre, Leiden, The Netherlands. a.de_breij@lumc.nl
Dijkshoorn
Lenie
L
Lagendijk
Ellen
E
van der Meer
Joke
J
Koster
Abraham
A
Bloemberg
Guido
G
Wolterbeek
Ron
R
van den Broek
Peterhans
P
Nibbering
Peter
P
D040981:Acinetobacter baumannii / Q000166:cytology* / Q000502:physiology* / Q000648:ultrastructure; D001422:Bacterial Adhesion; D018441:Biofilms / Q000254:growth & development*; D001980:Bronchi / Q000166:cytology; D002478:Cells, Cultured; D016207:Cytokines / Q000096:biosynthesis; D004847:Epithelial Cells / Q000166:cytology / Q000382:microbiology*; D006801:Humans; D008264:Macrophages / Q000378:metabolism / Q000382:microbiology; D013499:Surface Properties
D016207:Cytokines