title: Endosymbiotic bacterium Protochlamydia can survive in acanthamoebae following encystation.
abstract: Obligate intracellular bacteria are commonly seen as endosymbionts of acanthamoebae. However, whether endosymbionts can survive amoebal encystations remains a significant challenge in cellular biology. The survival of the endosymbiotic bacteria Protochlamydia belonging to environmental chlamydiae found in an amoebal isolate that we have previously reported (Environmental Microbiology Reports, DOI: 10.1111/j.1758-2229.2009.00094.x, 2009) following encystation was therefore assessed. The bacteria were observed in cysts and trophozoites reverted from cysts by analysis with transmission electron microscope, and the bacterial 16S rRNA transcripts were detected in amoeba cultures following encystations by reverse transcription polymerase chain reaction method. Furthermore, the bacterial growth was also confirmed, by fluorescent in situ hybridization analysis and the AIU assay that we have previously established (Applied Environmental Microbiology, 74: 6397-6404, 2008), in trophozoites reverted from cysts stored at 4°C for up to a month after encystation. Thus, these results demonstrated that Protochlamydia could survive in acanthamoebae following encystation. Our findings suggest that amoeba cysts might be further studied in order to understand their role in the environmental survival of endosymbionts.
authors.affiliation: Division of Biomedical Imaging Research, Division of Ultrastructural Research, and Department of Human Pathology, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan. Department of Medical Laboratory Sciences, Hokkaido University Graduate School of Health Sciences, Sapporo, Hokkaido 060-0812, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Nakamura
authors.forename: Junji
authors.initials: J
authors.lastname: Matsuo
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Hayashi
authors.forename: Kouhei
authors.initials: K
authors.lastname: Kawaguchi
authors.forename: Mitsutaka
authors.initials: M
authors.lastname: Yoshida
authors.forename: Kaori
authors.initials: K
authors.lastname: Takahashi
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Mizutani
authors.forename: Takashi
authors.initials: T
authors.lastname: Yao
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yamaguchi