Bartonella henselae
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Bartonella henselae (dark particles) in a human heart valve |
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| ( Regnery et al., 1992) Brenner et al., 1993 |
Bartonella henselae is a gram-negative rod bacterium and the causative agent of cat scratch disease .
properties
Bartonella spp . are gram-negative, aerobic , facultative intracellular bacteria. The bacterial genus is named after its discoverer Alberto Barton . They belong to the class of Alphaproteobacteria and are phylogenetically closely related to Brucella spp ., Agrobacterium spp . and Rhizobium spp. related.
The species Bartonella henselae was first described in 1990 using the 16S rRNA. The biochemical characterization took place in 1992, the species was named after the medical-technical assistant Diane Hensel . While it was initially assumed that only cats could be the carrier of the pathogen, we now know that the pathogen can be detected in a large number of mammals. Ticks are also discussed as carriers of B. henselae .
Besides Agrobacterium tumefaciens , B. henselae is the only bacterium that has been proven to be able to smuggle DNA into eukaryotic cells via a transport system. In a study with human epithelial cells, a plasmid was transferred from the bacterium via the type IV secretion system and expressed in the cell line. In addition to demonstrating that horizontal gene transfer between prokaryotes and eukaryotes is not an isolated case, the use of this system enables further methods for performing gene therapy .
Pathogenicity
After infection, children usually develop cat scratch disease (KKK). This disease, which is transmitted to humans by young cats or cat fleas , typically begins with a papule at the inoculation site , which is usually followed by self-limiting lymphadenitis of the regional lymph nodes .
Of all bacteria pathogenic to humans, only Bartonella have the ability to trigger vasculoproliferations . Immunosuppressed patients in particular (e.g. AIDS patients) can develop “ bacillary angiomatosis ” (BA; the skin is primarily affected) or “ peliosis hepatis ” (PH) if the liver is affected. In 1983 a case of this "atypical subcutaneous AIDS-associated infection" was reported for the first time. In 1991, Bartonella henselae was discovered by David Relman as the causative agent of "bacillary angiomatosis" through the pioneering molecular detection of the 16S rDNA of the pathogen and subsequently also cultivated from vasculoproliferative skin , bone or liver lesions of sick people. Today, both Bartonella henselae and Bartonella quintana are considered triggers for BA or PH.
Individual evidence
- ↑ DA Relman, JS Loutit, TM Schmidt, S. Falkow, LS Tompkins: The agent of bacillary angiomatosis. An approach to the identification of uncultured pathogens. In: The New England Journal of Medicine . Volume 323, Number 23, December 1990, ISSN 0028-4793 , pp. 1573-1580, doi : 10.1056 / NEJM199012063232301 , PMID 2233945 .
- ^ RL Regnery, BE Anderson, JE Clarridge, MC Rodriguez-Barradas, DC Jones, JH Carr: Characterization of a novel Rochalimaea species, R. henselae sp. nov., isolated from blood of a febrile, human immunodeficiency virus-positive patient. In: Journal of clinical microbiology. Volume 30, Number 2, February 1992, ISSN 0095-1137 , pp. 265-274, PMID 1371515 , PMC 265044 (free full text).
- ↑ G. Schröder, R. Schuelein u. a .: Conjugative DNA transfer into human cells by the VirB / VirD4 type IV secretion system of the bacterial pathogen Bartonella henselae. In: Proceedings of the National Academy of Sciences . Volume 108, Number 35, August 2011, pp. 14643-14648, ISSN 1091-6490 . doi : 10.1073 / pnas.1019074108 . PMID 21844337 . PMC 3167556 (free full text).