絞り込み

16525

広告

珍しい中型ティラノサウルス類の骨?…北海道 (読売新聞)

北海道大学は20日、北海道芦別市の白亜紀後期(約1億年~約6600万年前)の地層から見つかった恐竜の化石が、ティラノサウルス類の尾の骨である可能性が高いことが分...

  1. なぜ博士キャラは「〜じゃ」と話すの?リア...
  2. 【書評】中国のSF作家はどれだけ未来を見...
  3. エタノールから酢酸 合成方法を開発 (毎...
  4. DNAで恋が芽生える!新時代の婚活サービ...

ニュース一覧

Gene Acquisition by a Distinct Phyletic Group within Streptococcus pneumoniae Promotes Adhesion to the Ocular Epithelium.

著者 Antic I , Brothers KM , Stolzer M , Lai H , Powell E , Eutsey R , Cuevas RA , Miao X , Kowalski RP , Shanks RMQ , Durand D , Hiller NL
mSphere.2017 Sep-Oct ; 2(5):.
この記事をPubMed上で見るPubMedで表示
この記事をGoogle翻訳上で見る Google翻訳で開く

スターを付ける スターを付ける     (33view , 0users)

Full Text Sources

Streptococcus pneumoniae (pneumococcus) displays broad tissue tropism and infects multiple body sites in the human host. However, infections of the conjunctiva are limited to strains within a distinct phyletic group with multilocus sequence types ST448, ST344, ST1186, ST1270, and ST2315. In this study, we sequenced the genomes of six pneumococcal strains isolated from eye infections. The conjunctivitis isolates are grouped in a distinct phyletic group together with a subset of nasopharyngeal isolates. The keratitis (infection of the cornea) and endophthalmitis (infection of the vitreous body) isolates are grouped with the remainder of pneumococcal strains. Phenotypic characterization is consistent with morphological differences associated with the distinct phyletic group. Specifically, isolates from the distinct phyletic group form aggregates in planktonic cultures and chain-like structures in biofilms grown on abiotic surfaces. To begin to investigate the association between genotype and epidemiology, we focused on a predicted surface-exposed adhesin (SspB) encoded exclusively by this distinct phyletic group. Phylogenetic analysis of the gene encoding SspB in the context of a streptococcal species tree suggests that sspB was acquired by lateral gene transfer from Streptococcus suis. Furthermore, an sspB deletion mutant displays decreased adherence to cultured cells from the ocular epithelium compared to the isogenic wild-type and complemented strains. Together these findings suggest that acquisition of genes from outside the species has contributed to pneumococcal tissue tropism by enhancing the ability of a subset of strains to infect the ocular epithelium causing conjunctivitis. IMPORTANCE Changes in the gene content of pathogens can modify their ability to colonize and/or survive in different body sites in the human host. In this study, we investigate a gene acquisition event and its role in the pathogenesis of Streptococccus pneumoniae (pneumococcus). Our findings suggest that the gene encoding the predicted surface protein SspB has been transferred from Streptococcus suis (a distantly related streptococcal species) into a distinct set of pneumococcal strains. This group of strains distinguishes itself from the remainder of pneumococcal strains by extensive differences in genomic composition and by the ability to cause conjunctivitis. We find that the presence of sspB increases adherence of pneumococcus to the ocular epithelium. Thus, our data support the hypothesis that a subset of pneumococcal strains has gained genes from neighboring species that enhance their ability to colonize the epithelium of the eye, thus expanding into a new niche.
PMID: 29085912 [PubMed]
印刷用ページを開く Endnote用テキストダウンロード