Endosymbionts of Acanthamoeba isolated from domestic tap water in Korea.
In a previous study, we reported our discovery of Acanthamoeba contamination in domestic tap water; in that study, we determined that some Acanthamoeba strains harbor endosymbiotic bacteria, via our molecular characterization by mitochondrial DNA restriction fragment length polymorphism (Mt DNA RFLP). Five (29.4%) among 17 Acanthamoeba isolates contained endosymbionts in their cytoplasm, as demonstrated via orcein staining. In order to estimate their pathogenicity, we conducted a genetic characterization of the endosymbionts in Acanthamoeba isolated from domestic tap water via 16S rDNA sequencing. The endosymbionts of Acanthamoeba sp. KA/WP3 and KA/WP4 evidenced the highest level of similarity, at 97% of the recently published 16S rDNA sequence of the bacterium, Candidatus Amoebophilus asiaticus. The endosymbionts of Acanthamoeba sp. KA/WP8 and KA/WP12 shared a 97% sequence similarity with each other, and were also highly similar to Candidatus Odyssella thessalonicensis, a member of the alpha-proteobacteria. The endosymbiont of Acanthamoeba sp. KA/WP9 exhibits a high degree of similarity (85-95%) with genus Methylophilus, which is not yet known to harbor any endosymbionts. This is the first report, to the best of our knowledge, to show that Methylophilus spp. can live in the cytoplasm of Acanthamoeba.
Choi
Seon Hee
SH
Department of Parasitology, School of Medicine, Pusan National University, Busan, 602-739, Korea.
Cho
Min Kyoung
MK
Ahn
Soon Cheol
SC
Lee
Ji Eun
JE
Lee
Jong Soo
JS
Kim
Dong-Hee
DH
Xuan
Ying-Hua
YH
Hong
Yeon Chul
YC
Kong
Hyun Hee
HH
Chung
Dong Il
DI
Yu
Hak Sun
HS
D000048:Acanthamoeba / Q000302:isolation & purification / Q000382:microbiology* / Q000648:ultrastructure; D020561:Alphaproteobacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D000818:Animals; D041963:Bacteroidetes / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D005618:Fresh Water / Q000469:parasitology*; D007723:Korea; D020629:Methylophilus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D046529:Microscopy, Electron, Transmission; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D013559:Symbiosis
D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S