The Gram-negative genus Bartonella comprises arthropod-borne pathogens that
typically infect mammals in a host-specific manner. Bartonella bacilliformis and
Bartonella quintana are human-specific pathogens, while several zoonotic
bartonellae specific for diverse animal hosts infect humans as an incidental
host. Clinical manifestations of Bartonella infections range from mild symptoms
to life-threatening disease. Following transmission by blood-sucking arthropods
or traumatic contact with infected animals, bartonellae display sequential
tropisms towards endothelial and possibly other nucleated cells and
erythrocytes, the latter in a host-specific manner. Attachment to the
extracellular matrix (ECM) and to nucleated cells is mediated by surface-exposed
bacterial adhesins, in particular trimeric autotransporter adhesins (TAAs). The
subsequent engulfment of the pathogen into a vacuolar structure follows a unique
series of events whereby the pathogen avoids the endolysosomal compartments. For
Bartonella henselae and assumingly most other species, the infection process is
aided at different steps by Bartonella effector proteins (Beps). They are
injected into host cells through the type IV secretion system (T4SS) VirB/D4 and
subvert host cellular functions to favor pathogen uptake. Bacterial binding to
erythrocytes is mediated by Trw, another T4SS, in a strictly host-specific
manner, followed by pathogen-forced uptake involving the IalB invasin and
subsequent replication and persistence within a membrane-bound intraerythrocytic
compartment.
Source:
© 2012 Blackwell Publishing Ltd
http://onlinelibrary.wiley.com/doi/1...806.x/abstract
No comments:
Post a Comment