Journal of Microbiology

Research Support, Non-U.S. Gov'ts

Full Sequence Analysis and Characterization of a Human Astrovirus Type 1 Isolate from South Korea: Sung-Geun Lee , Lae-Hyung Kang , Weon-Hwa Jheong , Mi-Hwa Oh , Gyu-Cheol Lee , Sujeong Park , Soon-Young Paik; J. Microbiol. 2013;51(1):123-129. Published online March 2, 2013; DOI: https://doi.org/10.1007/s12275-013-2505-2

Abstract: Human astroviruses are recognized as an important cause of infantile gastroenteritis around the world. In South Korea, sporadic cases of HAstV infection have been reported since 2002. However, hitherto, there have been no studies reporting the whole genome sequence of an HAstV isolate from South Korea. Hence, we sequenced and analyzed the entire genome of an HAstV-1 strain (lhar) that was isolated in Seoul, South Korea. The whole-genome sequence analysis revealed 3 open reading frames comprising the whole genome: ORF1a (2,763 bp), ORF1b (1,548 bp), and ORF2 (2,364 bp). The lhar strain showed amino acid identities with 8 other reference strains of 87.6–98.7%, 94.2–98.8%, and 62.6–99.0% in the ORF1a, ORF1b, and ORF2 regions, respectively. The amino acid sequence of the capsid region encoded by ORF2 was compared with a total of 19 HAstV-1 strains and 8 HAstVs reference strains isolated in various countries. This revealed 1 amino acid substitution, at aa412 (Pro → Arg) in ORF2. This study, the first to report the fulllength sequence of an HAstV isolated in South Korea, is meaningful in that it can be used as a full-length HAstV sequence standard for future comparison studies. It may also prove useful to the field of public health field by facilitating the diagnosis and the prediction of new emerging variants.

Phylogeny of a Novel “Helicobacter heilmannii” Organism from a Japanese Patient with Chronic Gastritis Based on DNA Sequence Analysis of 16S rRNA and Urease Genes: Takehisa Matsumoto , Masatomo Kawakubo , Mayumi Shiohara , Toshiko Kumagai , Eiko Hidaka , Kazuyoshi Yamauchi , Kozue Oana , Kenji Matsuzawa , Hiroyoshi Ota , Yoshiyuki Kawakami; J. Microbiol. 2009;47(2):201-207. Published online May 2, 2009; DOI: https://doi.org/10.1007/s12275-008-0313-x

Abstract: “Helicobacter heilmannii” is an uncultivable spiral-shaped bacterium inhabiting the human gastric mucosa. It is larger and more tightly-coiled than H. pylori. We encountered a patient with chronic gastritis infected a “H. heilmannii”-like organism (HHLO), designated as SH6. Gastric mucosa derived from the patient was orally ingested by specific pathogen free mice. Colonization of the mice by SH6 was confirmed by electron microscopy of gastric tissue specimens. In an attempt to characterize SH6, 16S rRNA and urease genes were sequenced. The 16S rRNA gene sequence was most similar (99.4%; 1,437/1,445 bp) to HHLO C4E from a cheetah. However, the urease gene sequence displayed low similarity (81.7%; 1,240/1,516 bp) with HHLO C4E. Taxonomic analysis disclosed that SH6 represents a novel strain and should constitute a novel taxon in the phylogenetic trees, being discriminated from any other taxon, with the ability of infecting human gastric mucosa.

Sequence and Phylogenetic Analyses of Novel Glucosyltransferase Genes of Mutans Streptococci Isolated from Pig Oral Cavity: Noriko Shinozaki-Kuwahara , Kazuko Takada , Masatomo Hirasawa; J. Microbiol. 2008;46(2):202-208. Published online June 11, 2008; DOI: https://doi.org/10.1007/s12275-007-0199-z

Abstract: Nucleotide sequences of water-insoluble glucan-producing glucosyltransferase (gtf) genes of new mutans streptococci isolated from pig oral cavity, Streptococcus orisuis JCM14035, and of Streptococcus criceti HS-6 were determined. The gtf gene of S. orisuis JCM14035 consisted of a 4,401 bp ORF encoding for a 1,466 amino acids, and was revealed to belong to the gtfI group. The percent homology of amino acid sequence of the GTF-I from S. orisuis and S. criceti are 95.0%, however, this score ranges from 77.0% to 78.0% when compared to Streptococcus sobrinus 6715. The deduced N-terminal amino acid sequence was considered responsible for the secretion of GTF-I in S. orisuis JCM14035 and S. criceti HS-6 with high similarity to known GTF proteins from other streptococci. In addition, two other conserved regions, i.e., N-terminal putative catalytic-site and C-terminal glucan binding domain, were also found in GTF-Is of S. orisuis JCM14035 and S. criceti HS-6. Phylogenetic analysis suggested that S. orisuis JCM14035 and S. criceti HS-6, closely related to each other, resemble S. sobrinus and S. downei based on the amino acid sequences of the GTFs.

Search