Emerging Infectious Diseases ( IF 7.2 ) Pub Date : 2020-03-02 , DOI: 10.3201/eid2604.190717 Yi-Yin Chen , Yu-Chia Hsieh , Yu-Nong Gong , Wei-Chao Liao , Shiao-Wen Li , Ian Yi-Feng Chang , Tzu-Lung Lin , Ching-Tai Huang , Cheng-Hsiu Chiu , Tsu-Lan Wu , Lin-Hui Su , Ting-Hsuan Li , Ya-Yu Huang
Incidence of invasive pneumococcal disease caused by antimicrobial-resistant Streptococcus pneumoniae types not included in pneumococcal conjugate vaccines has increased, including a penicillin- and meropenem-resistant serotype 15A-ST63 clone in Japan. During 2013–2017, we collected 206 invasive pneumococcal isolates in Taiwan for penicillin and meropenem susceptibility testing. We found serotypes 15B/C-ST83 and 15A-ST63 were the most prevalent penicillin- and meropenem-resistant clones. A transformation study confirmed that penicillin-binding protein (PBP) 2b was the primary meropenem resistance determinant, and PBP1a was essential for high-level resistance. The rate of serotype 15B/C-ST83 increased during the study. All 15B/C-ST83 isolates showed an ermB macrolide resistance genotype. Prediction analysis of recombination sites revealed 12 recombination regions in 15B/C-ST83 compared with the S. pneumoniae Spain23F-ST81 genome. Pneumococcal clones rapidly recombine to acquire survival advantages and undergo local expansion under the selective pressure exerted by vaccines and antimicrobial drugs. The spread of 15B/C-ST83 is alarming for countries with high antimicrobial pressure.