1. CpaA a novel protease from Acinetobacter baumannii clinical isolates deregulates blood coagulation.
- Author
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Tilley D, Law R, Warren S, Samis JA, and Kumar A
- Subjects
- Acinetobacter Infections microbiology, Acinetobacter baumannii isolation & purification, Bacterial Proteins chemistry, Blood Coagulation, Catalytic Domain, Conserved Sequence, Fibrinogen chemistry, Humans, Metalloendopeptidases chemistry, Partial Thromboplastin Time, Proteolysis, Sequence Analysis, Protein, Acinetobacter Infections blood, Acinetobacter baumannii enzymology, Bacterial Proteins physiology, Metalloendopeptidases physiology
- Abstract
Acinetobacter baumannii is an important nosocomial pathogen that displays high antibiotic resistance. It causes a variety of infections including pneumonias and sepsis which may result in disseminated intravascular coagulation. In this work, we identify and characterize a novel secreted, zinc-dependent, metallo-endopeptidase CpaA (coagulation targeting metallo-endopeptidase of Acinetobacter baumannii) which deregulates human blood coagulation in vitro and thus is likely to contribute to A. baumannii virulence. Three quarters of the clinical isolates tested (n = 16) had the cpaA gene; however, it was absent from two type strains, A. baumannii ATCC 17978 and A. baumannii ATCC 19606. The CpaA protein was purified from one clinical isolate and was able to cleave purified factor (F) V and fibrinogen and reduce the coagulation activity of FV in human plasma. CpaA-treated plasma showed reduced clotting activity in contact pathway-activated partial thromboplastin time (aPTT) assays, but increased clotting activity in tissue factor pathway prothrombin time (PT) assays. A significant portion of clinically relevant A. baumannii isolates secrete a protease which targets and deregulates the coagulation system., (© 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.)
- Published
- 2014
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