Therefore, S. aureus has two independent factors responsible for susceptibility to bacitracin. In conclusion, we found that a TCS, designated BceRS, senses bacitracin and also positively regulates the expression of two ABC transporters that function in bacitracin efflux. This work was supported by a grant-in-aid for scientific research from Health and Labor Sciences Research Grants from the Ministry of Health and Welfare of Japan. “
“Coxiella burnetii is a Gram-negative

pleomorphic bacterium and the causative agent of Q fever. During infection, the pathogen survives and replicates within a phagosome-like parasitophorous vacuole while influencing cellular functions throughout the host cell, indicating a capacity for effector protein secretion. Analysis of the C. burnetii (RSA 493 strain) genome sequence indicates that C. burnetii contains genes with homology to the Legionella selleckchem pneumophila Dot/Icm type IVB secretion system (T4BSS). T4BSSs have only been described in L. pneumophila and C. burnetii, marking it a unique virulence determinate. Characterization of bacterial virulence determinants ranging from autotransporter proteins to diverse secretion systems http://www.selleckchem.com/products/Trichostatin-A.html suggests that polar localization may be a virulence mechanism hallmark. To characterize T4BSS subcellular localization in C. burnetii, we analyzed C.

burnetii-infected Vero cells by indirect immunofluorescent antibody (IFA) and immunoelectron microscopy (IEM). Using antibodies against the C. burnetii T4BSS homologs IcmT, IcmV, and DotH, IFA show that these proteins are localized to the poles of the bacterium. IEM supports this finding, showing that antibodies against C. burnetii IcmT and DotH preferentially

localize to the bacterial cell pole(s). Together, these data demonstrate that the C. burnetii T4BSS localizes to the pole(s) of the bacterium during infection of host cells. The zoonotic disease Q fever is caused by Coxiella burnetii, an obligate intracellular bacterial pathogen (Maurin & Raoult, 1999) that has only recently been propagated in a cell-free medium (Omsland et al., 2009). Coxiella burnetii undergoes a biphasic life cycle initiated by the metabolically inactive, environmentally Mannose-binding protein-associated serine protease stable small cell variant (SCV) form of the bacteria. The SCV then goes on to develop into the replicative large cell variant (LCV) form. This may occur by 8 h of host cell infection (McCaul, 1991; Coleman et al., 2004). During the infectious cycle, C. burnetii lives within a parasitophorous vacuole (PV) that has the attributes of a mature phagolysosome (Akporiaye et al., 1983; Heinzen et al., 1996; Ghigo et al., 2002; Gutierrez et al., 2005; Sauer et al., 2005; Howe & Heinzen, 2006; Romano et al., 2007). Recent studies indicate that C. burnetii protein synthesis is required for the pathogen to influence host cell processes such as apoptosis (Voth & Heinzen, 2009) and vesicular trafficking (Howe et al., 2003a, b) from within the PV.