Survival and transfer ability of phylogenetically diverse bacterial endosymbionts in environmental Acanthamoeba isolates
Article first published online: 17 NOV 2009
© 2009 Society for Applied Microbiology and Blackwell Publishing Ltd
Environmental Microbiology Reports
Special Issue: Symbiosis. Editors: Professors Paola Bonfante, Karen Visick, and Moriya Ohkuma
Volume 2, Issue 4, pages 524–533, August 2010
How to Cite
Matsuo, J., Kawaguchi, K., Nakamura, S., Hayashi, Y., Yoshida, M., Takahashi, K., Mizutani, Y., Yao, T. and Yamaguchi, H. (2010), Survival and transfer ability of phylogenetically diverse bacterial endosymbionts in environmental Acanthamoeba isolates. Environmental Microbiology Reports, 2: 524–533. doi: 10.1111/j.1758-2229.2009.00094.x
- Issue published online: 16 JUL 2010
- Article first published online: 17 NOV 2009
- Received 17 April, 2009; accepted 5 October, 2009.
Obligate intracellular bacteria are commonly found as endosymbionts of acanthamoebae; however, their survival in and ability to transfer to amoebae are currently uncharacterized. In this study, six bacterial endosymbionts, found in five environmental Acanthamoeba isolates (S13, R18, S23, S31, S40) from different locations of Sapporo city, Japan, were characterized. Phylogenetic analysis revealed that three bacterial endosymbionts (eS23, eS31, eS40a) belonged to α- and β-Proteobacteria phyla and the remaining endosymbionts (eS13, eR18, eS40b) belonged to the order Chlamydiales. The Acanthamoeba isolate (S40) contained two phylogenetically different bacterial endosymbionts (eS40a, eS40b). Fluorescent in situ hybridization analysis showed that all bacterial endosymbionts were diffusely localized within amoebae. Transmission electron microscopy also showed that the endosymbionts were rod-shaped (eS23, eS31, eS40a) or sphere- or crescent-shaped (eS13, eR18, eS40b). No successful culture of these bacteria was achieved using conventional culture methods, but the viability of endosymbionts was confirmed by live/dead staining and RT-PCR methods. However, endosymbionts (except eR18) derived from original host cells lost the ability to be transferred to another Acanthamoebae strains [ATCC strain (C3), environmental strains (S14, R23, S24)]. Thus, our data demonstrate that phylogenetically diverse bacterial endosymbionts found in amoebae maintain a stable interaction with amoebae, but the transferability is limited.