The transient nonchemotactic phenotype of V cholerae shed in sto

The transient nonchemotactic phenotype of V. cholerae shed in stool enhances infectivity within the next host (Merrell et al., 2002), by allowing the organisms to colonize

regions of the upper intestine not colonized by laboratory-grown bacteria. This suggests that chemotaxis leads the bacteria to the lower small intestine. AcfB and TcpI, by virtue of being positively regulated by ToxT, are specifically expressed inside the host intestine, and because the loss of both leads to lower levels of intestinal colonization, we suggest that these MCPs contribute to chemotaxis toward the correct intestinal location. However, the acfB tcpI Dasatinib mutant colonized the distal end of the intestine, similar to the wild-type strain, albeit at lower levels, and so these MCPs may be involved in localization selleck kinase inhibitor within the microenvironment of the ileum. MCPs can function by either binding a chemoattractant, which facilitates swimming toward a gradient, or a chemorepellant, which facilitates swimming away from a gradient. We propose that AcfB and TcpI either recognize attractants within the intestinal crypts in the distal ileum or repellants present within the intestinal lumen at this location.

Upon acquisition of the VPI, V. cholerae gains the colonization factor and the regulatory elements to allow this organism to successfully colonize the intestine in response to the environmental conditions present there. The contribution of MCPs located within the VPI to intestinal colonization suggests that the VPI

also contains the ‘road map’ that directs the bacteria to the appropriate location to colonize. We thank Andy Camilli for providing plasmids. This work was supported by AI 43486 to K.E.K. Fig. S1. ClustalW alignment of AcfB and TcpI. Please note: Wiley-Blackwell is not responsible for the content or functionality of any supporting materials supplied by the authors. Any queries (other than missing material) should be directed to the corresponding author for the article. “
“Fungal infections with multiple resistance to conventional antifungals are increasingly becoming a medical problem, and there is an urgent need for new antifungal compounds with novel mechanisms of action. Here, we show that Carbohydrate aurein 2.5, a naturally occurring peptide antibiotic, displays activity against the fungal strains: Rhodotorula rubra and Schizosaccharomyces pombe (MICs < 130 μM). The peptide adopted high levels of membrane-interactive α-helical structure (> 65%) in the presence of lipid membranes derived from these organisms and showed strong propensities to penetrate (π ≥ 13 mN m−1) and lyse them (> 70%). Based on these data, we suggest that aurein 2.5 kills yeasts via membranolytic mechanisms and may act as a template for the development of therapeutically useful antifungal agents. “
“A dimeric cytochrome c with an apparent molecular mass of 25 kDa was isolated from an anammox bacterium, strain KSU-1, in a relatively large quantity. This protein was named the NaxLS complex.

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