Serotype Distribution and Antimicrobial Susceptibility of Streptococcus pneumoniae in Pre- and Post- PCV7/13 Eras, Taiwan, 2002–2018

Abstract

In Taiwan, the 7-valent pneumococcal conjugate vaccine (PCV7) was introduced in 2006 and a PCV13 national childhood catchup program was implemented in 2013. To delineate the trend of serotype distribution and antimicrobial susceptibility following vaccination programs, we investigated a total of 1845 Streptococcus pneumoniae isolates collected biennially between 2002 and 2018 over a 3-month period from 25 hospitals. The number of isolates collected over the years decreased significantly in all age groups, from a total of 320 isolates in 2002 (pre-PCV), to 196 in 2010 (post-PCV7/pre-PCV13), to 89 in 2018 (post-PCV13). Overall, PCV7/PCV13 serotypes comprised 66.9%/76.3%, 53.1%/78.1%, and 15.7%/31.5% of isolates in 2002, 2010, and 2018, respectively. The leading serotypes in the pre-PCV era were 23F, 19F, 6B, and 14, while serotype 19A predominated in the post-PCV7/pre-PCV13 era, but nonvaccine serotypes (NVT) 15A (18.0%) and 23A (15.7%) surpassed 19A (10.1%) to become the top two leading serotypes in 2018. All the major serotypes, including the emergent serotypes 15A and 23A, were multidrug-resistant with high rates of nonsusceptibility to β-lactam (except serotype 3) and several non-β-lactam agents. PFGE and MLST revealed that while meropenem-susceptible serotype 15A-ST3058 isolates and a serotype 23A-ST338 clone existed in earlier years, rise and spread of meropenemnon-susceptible serotype 15A-ST63 and serotype 23A-ST166 clones occurred in recent years. We conclude that successive implementation of PCVs has led to a marked decrease in pneumococcal isolate burden, but the replacement by meropenem-nonsusceptible NVT 15A and 23A highlights the need for continued local surveillance to track pneumococcal evolution in each region to help vaccine polyvalency decisions.

Serotype distribution and antibiotic resistance of Streptococcus pneumoniae isolates collected from unvaccinated children with pneumonia at a province in central Vietnam

“…Besides, the rates of decreased susceptibility to penicillins and cephalosporins showed a rising trend. This result is in agreement with previous studies conducted in China, Taiwan and Vietnam, where more than 50% of patients infected with non-susceptible to penicillins and cephalosporins (3,24,29,30,35). In our study, all the S. pneumoniae strains were susceptible to RIF, CLP, VAN, MXF and LIN.…”

23-valent polysaccharide vaccine (PPSV23)-targeted serotype-specific identification of Streptococcus pneumoniae using the loop-mediated isothermal amplification (LAMP) method

“…Pneumococcal serotypes often are examined using blood samples, as they can be collected non-invasively, and a positive result indicates an IPD [ 34 ]. Blood was collected from 5 healthy volunteers and heparinized for storage.…”

National surveillance of antimicrobial susceptibilities to dalbavancin, telavancin, tedizolid, eravacycline, omadacycline and other comparator antibiotics and serotype distribution of invasive Streptococcus pneumoniae isolates in adults: results from the Surveillance of Multicenter Antimicrobial Resistance in Taiwan (SMART) programme in 2017–2020

“…The prevalence of pneumococcal resistance to penicillin, macrolides, third-generation cephalosporins and trimethoprim/sulfamethoxazole is quite high in Taiwan [ 15 , 16 ]. This might be associated with the spread of serotype-specific clones, such as levofloxacin-non-susceptible serotype 11A-ST3642 and meropenem-non-susceptible serotype 15A-ST63, 23A-ST166 and 15B/C-ST83 clones [17] , [18] , [19] . In addition, more patients with chronic illness might be exposed to more antibiotics and cause more antibiotic resistance [20] .…”