7/2/2023 0 Comments Lunar cycle october 2016![]() ![]() burgdorferi from the skin to distant tissues, establishment of persistent infection in mice, transmission from the tick vector to the murine host, and optimal survival in ticks ( 6, 7, 10). Motility is absolutely required for migration of B. burgdorferi is a highly motile organism whose motility is provided by flagella that are enclosed by the outer membrane and thus are called periplasmic flagella ( 6, – 9). Spirochete-infected ticks efficiently transmit the bacteria during a blood meal to the vertebrate host, where the organisms disseminate from the initial site of inoculation in the dermis to several distant tissues, such as tibiotarsal joints, heart, and the nervous system, where they persist to produce various clinical manifestations ( 3, – 5). During its natural enzootic cycle, the organism must survive within a vertebrate host (usually a rodent) and a tick vector of an Ixodes species. burgdorferi virulence determinant that is required for productive infection within vertebrate, but not tick, hosts.īorrelia burgdorferi is the causative organism of Lyme disease, which is the most common vector-borne illness in the United States and Europe ( 1, 2). We propose that CheY2 serves as a regulator for a B. Our data suggest that CheY2, despite resembling a typical response regulator, functions distinctively from most other chemotaxis CheY proteins. Moreover, while Δ cheY2 spirochetes are able to survive normally in the Ixodes ticks, mice fed upon by the Δ cheY2-infected ticks did not develop a persistent infection in the murine host. Specifically, the cheY2 mutants were severely attenuated in murine infection and dissemination to distant tissues after needle inoculation. Mutants deficient in this protein exhibit normal motility and chemotaxis in vitro but show reduced virulence in mice. Borrelia burgdorferi appears to be notably different, in that it has three cheY genes, and our current studies on cheY2 suggests that it has varied effects on different aspects of the natural infection cycle. Most motile bacteria possess at least one CheY response regulator that is typically dedicated to the control of motility and which is usually essential for virulence. However, the functions of most of those additional genes are unknown. ![]() Even though more than 50% of all sequenced prokaryotic genomes possess at least one chemotaxis signaling system, many of those genomes contain multiple copies of a chemotaxis gene. The requirements for bacterial chemotaxis and motility range from dispensable to crucial for host colonization. ![]()
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