Archive for October, 2010

Full article: http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1000499#top

Excerpt:

The protozoan parasite Theileria inhabits the host cell cytoplasm and possesses the unique capacity to transform the cells it infects, inducing continuous proliferation and protection against apoptosis. The transforming schizont is a multinucleated syncytium that resides free in the host cell cytoplasm and is strictly intracellular. To maintain transformation, it is crucial that this syncytium is divided over the two daughter cells at each host cell cytokinesis. This process was dissected using different cell cycle synchronization methods in combination with the targeted application of specific inhibitors. We found that Theileria schizonts associate with newly formed host cell microtubules that emanate from the spindle poles, positioning the parasite at the equatorial region of the mitotic cell where host cell chromosomes assemble during metaphase. During anaphase, the schizont interacts closely with host cell central spindle. As part of this process, the schizont recruits a host cell mitotic kinase, Polo-like kinase 1, and we established that parasite association with host cell central spindles requires Polo-like kinase 1 catalytic activity. Blocking the interaction between the schizont and astral as well as central spindle microtubules prevented parasite segregation between the daughter cells during cytokinesis. Our findings provide a striking example of how an intracellular eukaryotic pathogen that evolved ways to induce the uncontrolled proliferation of the cells it infects usurps the host cell mitotic machinery, including Polo-like kinase 1, one of the pivotal mitotic kinases, to ensure its own persistence and survival.

Full article: http://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&id=20833105&retmode=ref&cmd=prlinks

Excerpt:

After 2 decades of Bartonella research, knowledge on transmission
and pathology of these bacteria is still limited. Bartonella spp.
have emerged to be important pathogens in human and veterinary
medicine. For humans, B. henselae is considered to represent the
most relevant zoonotic Bartonella species and is responsible for
cat scratch disease, bacillary angiomatosis, and other disorders.
Over the years, many Bartonella species have been isolated from
humans, cats, dogs, and other mammals, and infections range from
an asymptomatic state (e.g., animal-specific species) to even
life-threatening diseases (e.g., Oroya fever). It is obvious that
the analysis of pathogenicity mechanisms underlying Bartonella
infections is needed to increase our understanding of how these
pathogens adapt to their mammalian hosts resulting in acute or
chronic diseases. Copyright (c) 2010. Published by Elsevier GmbH.

Full article: http://jnnp.bmj.com/content/early/2010/08/13/jnnp.2009.191940.short?rss=1

Excerpt:

We report three patients with a brachial plexus neuropathy diagnosed as neuralgic amyotrophy (NA) preceded by a proven Bartonella henselae infection. Neuralgic amyotrophy is a disabling disease involving the brachial plexus, with attacks of severe shoulder and arm pain followed by weakness and sensory involvement.1 Several observations support the hypothesis of an immune-mediated genesis. First, brachial plexus biopsies of NA patients in the (sub)acute stage show inflammatory changes.2 3 Second, antiganglioside antibodies are reported to be associated with NA.1 4 Third, several immune-triggering events, most frequently infections (50%), are known to precede NA.1–4 Various micro-organisms preceding NA have been reported (see table 1) but not yet B henselae.
View this table: