論文

査読有り 国際誌
2019年

Middle East Respiratory Syndrome Coronavirus in Dromedaries in Ethiopia Is Antigenically Different From the Middle East Isolate EMC.

Frontiers in microbiology
  • Kazuya Shirato
  • ,
  • Simenew Keskes Melaku
  • ,
  • Kengo Kawachi
  • ,
  • Naganori Nao
  • ,
  • Naoko Iwata-Yoshikawa
  • ,
  • Miyuki Kawase
  • ,
  • Wataru Kamitani
  • ,
  • Shutoku Matsuyama
  • ,
  • Tesfaye Sisay Tessema
  • ,
  • Hiroshi Sentsui

10
10
開始ページ
1326
終了ページ
1326
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.3389/fmicb.2019.01326

Middle East respiratory syndrome (MERS) is an emerging respiratory disease caused by the MERS coronavirus (MERS-CoV). MERS has been endemic to Saudi Arabia since 2012. The reservoir of MERS-CoV is the dromedary camel, suggesting that MERS is primarily a zoonotic disease. MERS-CoV is common in dromedaries throughout the Middle East, North Africa, and East Africa as evidenced by neutralizing antibodies against MERS-CoV; however, human cases have remained limited to the Middle East. To better understand the cause of this difference, the virological properties of African camel MERS-CoV were analyzed based on the spike (S) protein in Ethiopia. Nasal swabs were collected from 258 young dromedaries (≤ 2 years old) in the Afar region of Ethiopia, of which 39 were positive for MERS-CoV, as confirmed by genetic tests. All positive tests were exclusive to the Amibara woreda region. Using next-generation sequencing, two full-length genomes of Amibara isolates were successfully decoded; both isolates belonged to the C2 clade based on phylogenetic analysis of full-length and S protein sequences. Recombinant EMC isolates of MERS-CoV, in which the S protein is replaced with those of Amibara isolates, were then generated to test the roles of these proteins in viral properties. Amibara S recombinants replicated more slowly in cultured cells than in EMC S recombinants. In neutralizing assays, Amibara S recombinants were neutralized by lower concentrations of sera from both Ethiopian dromedaries and EMC isolate (wild-type)-immunized mouse sera, relative to the EMC S recombinants, indicating that viruses coated in the Amibara S protein were easier to neutralize than the EMC S protein. Neutralization experiments performed using S1/S2 chimeric recombinants of the EMC and Amibara S proteins showed that the neutralization profile was dependent on the S1 region of the S protein. These results suggest that the slower viral replication and the ease of neutralization seen in the Ethiopian MERS-CoV are due to strain-specific differences in the S protein and may account for the absence of human MERS-CoV cases in Ethiopia.

リンク情報
DOI
https://doi.org/10.3389/fmicb.2019.01326
PubMed
https://www.ncbi.nlm.nih.gov/pubmed/31275264
PubMed Central
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6593072
ID情報
  • DOI : 10.3389/fmicb.2019.01326
  • PubMed ID : 31275264
  • PubMed Central 記事ID : PMC6593072

エクスポート
BibTeX RIS