#WGS #analysis of #MDR #serotype 15A #Streptococcus pneumoniae in #Japan and the emergence of a highly resistant serotype 15A-ST9084 clone (Antimicrob Agents Chemother., abstract)

[Source: Antimicrobial Agents and Chemotherapy, full page: (LINK). Abstract, edited.]

Whole-genome sequencing analysis of multidrug-resistant serotype 15A Streptococcus pneumoniae in Japan and the emergence of a highly resistant serotype 15A-ST9084 clone

Satoshi Nakano, Takao Fujisawa, Yutaka Ito, Bin Chang, Yasufumi Matsumura, Masaki Yamamoto, Shigeru Suga, Makoto Ohnishi, Miki Nagao

DOI: 10.1128/AAC.02579-18



Since the introduction of pneumococcal conjugate vaccines, an increase in the incidence of disease attributable to serotype 15A-ST63 pneumococci has been observed in many regions worldwide. We conducted a nationwide pediatric pneumococcal infection surveillance study between 2012 and 2014 in Japan. In the surveillance study, we detected multidrug-resistant serotype 15A-CC63 strains (resistant to macrolides, penicillin, cefotaxime and meropenem); in this study, we analyzed these resistant isolates to determine the dynamics and mechanism of resistance using whole-genome sequencing. In most of the penicillin-, cefotaxime- and meropenem-resistant strains, recombination occurred in the pbp2x region resulting in the acquisition of additional cefotaxime resistance to penicillin and meropenem. In the multidrug-resistant serotype 15A-CC63 strains, we identified a specific clone with ST9084, and all of the isolates were recovered from Yamaguchi prefecture in Japan. All of the serotype 15A-ST9084 isolates had a novel pbp2x-43 that was inserted by recombination events. The conserved amino acid motif profiles of pbp1a, pbp2b and pbp2x of the strains were identical to those in serotype 19A-ST320. A Bayesian analysis-based date estimation suggested that this clone emerged in approximately 2002 before the introduction of PCV in Japan. This clone should be monitored because serotype 15A is not contained in the currently used PCV13 and it was resistance to beta-lactams, which are often use in a clinical setting.

Copyright © 2019 American Society for Microbiology. All Rights Reserved.

Keywords: Antibiotics; Drugs Resistance; Beta-lactams; Penicillin; Cefotaxime; Meropenem; S. pneumoniae; Japan.


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Giuseppe Michieli

I am an Italian blogger, active since 2005 with main focus on emerging infectious diseases such as avian influenza, SARS, antibiotics resistance, and many other global Health issues. Other fields of interest are: climate change, global warming, geological and biological sciences. My activity consists mainly in collection and analysis of news, public services updates, confronting sources and making decision about what are the 'signals' of an impending crisis (an outbreak, for example). When a signal is detected, I follow traces during the entire course of an event. I started in 2005 my blog ''A TIME'S MEMORY'', now with more than 40,000 posts and 3 millions of web interactions. Subsequently I added an Italian Language blog, then discontinued because of very low traffic and interest. I contributed for seven years to a public forum (FluTrackers.com) in the midst of the Ebola epidemic in West Africa in 2014, I left the site to continue alone my data tracking job.