Effect of antibiotic-induced morphological changes on surface properties, motility and adhesion of nosocomial Pseudomonas aeruginosa strains under different physiological states.
OBJECTIVE
To investigate the influence of antibiotic-induced morphological changes on adhesion and motility abilities and surface properties of nosocomial Pseudomonas aeruginosa under different physiological states.


RESULTS
The effects of subinhibitory concentration (sub-MIC) of Piperacillin/Tazobactam (P/T) and Imipenem (IMP) were studied on P. aeruginosa adhesion (1 h) using a modified microtitre-plate assay, on their ability to swim and to twitch, on surface hydrophobicity and on acid-base interactions of P. aeruginosa strains by measuring their ability to adhere to n-hexadecane, chloroform and ethyl acetate, respectively. Our results show that antibiotic-induced morphological changes and bacterial physiological state can affect differently surface properties, motility and adhesion abilities of P. aeruginosa.


CONCLUSIONS
Under different physiological states P/T induced morphological changes, reduced motility abilities, decreased adhesion to polystyrene and cell surface hydrophobicity (CSH). Moreover, P/T and IMP led to similar changes in exponential population adhesion to chloroform and ethyl acetate. Additionally, IMP induced morphological changes and showed no differences on CSH, adhesion and motility abilities in both growth phases.


CONCLUSIONS
Adhesion is an attractive target for new antibacterial strategies, namely by using sub-MIC antibiotics that induce morphological, motility and surface properties changes, which are dependent of P. aeruginosa phenotype and physiological state.
Fonseca
A P
AP
Department of Microbiology, Faculty of Medicine, University of Porto, Porto, Portugal. apfonseca05@sapo.pt
Sousa
J C
JC
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001422:Bacterial Adhesion / Q000187:drug effects; D018441:Biofilms; D015378:Imipenem / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D008854:Microscopy, Electron; D009068:Movement / Q000187:drug effects; D009154:Mutation; D010878:Piperacillin / Q000494:pharmacology; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000235:genetics / Q000648:ultrastructure*; D013045:Species Specificity
D000900:Anti-Bacterial Agents; D015378:Imipenem; D010878:Piperacillin