Intracellular bacteria in ciliates Authors Hans-Dieter Görtz Department of Zoology, University of Stuttgart. Stuttgart, Germany Keywords: ciliates, intracellular bacteria, symbionts, killer toxins Abstract Ciliates are frequently colonized by other micro-organisms. The large size of ciliate cells offers habitats for hundreds to thousands of bacteria in different compartments, such as cytoplasm, nuclei and even perinuclear spaces. Size, phagocytic feeding habit and other features appear to be favorable pre-adaptations of ciliates for symbiosis with bacteria. Certain intracellular bacteria are permanent symbionts that are not infectious, whereas others are highly infectious. Both types show specific adaptations. With their wide spectrum of phylogenetic positions, intracellular bacteria in ciliates show relationships to di€erent taxa of free-living bacteria and even archaea. Certain symbionts may be deleterious for their host ciliates, whereas others may provide a selective advantage under appropriate conditions or even be essential for the host cells. Depending on the nature of a symbiont, its prevalence in a host population may be low or high. Symbionts that express a killer toxin a€ecting non-infected ciliates achieve high infection rates in a host population, whereas certain infectious bacteria may only show a low prevalence. Downloads PDF Published 2010-03-12 Issue Vol. 4 No. 3 (2001) Section Review Articles License Submission of a manuscript to International Microbiology implies: that the work described has not been published before, including publication in the World Wide Web (except in the form of an Abstract or as part of a published lecture, review, or thesis); that it is not under consideration for publication elsewhere; that all the coauthors have agreed to its publication. The corresponding author signs for and accepts responsability for releasing this material and will act on behalf of any and all coauthors regarding the editorial review and publication process.If an article is accepted for publication in International Microbiology, the authors (or other copyright holder) must transfer to the journal the right–not exclusive–to reproduce and distribute the article including reprints, translations, photographic reproductions, microform, electronic form (offline, online) or any other reproductions of similar nature. Nevertheless, all article in International Microbiology will be available on the Internet to any reader at no cost. The journal allows users to freely download, copy, print, distribute, search, and link to the full text of any article, provided the authorship and source of the published article is cited. The copyright owner's consent does not include copying for new works, or resale. In these cases, the specific written permission of International Microbiology must first be obtained.Authors are requested to create a link to the published article on the journal's website. The link must be accompanied by the following text: "The original publication is available on LINK at <http://www.im.microbios.org>. Please use the appropiate URL for the article in LINK. Articles disseminated via LINK are indexed, abstracted, and referenced by many abstracting and information services, bibliographic networks, subscription agencies, library networks, and consortia.
