title: Serotypes, antimicrobial susceptibility, and molecular epidemiology of invasive and non-invasive Streptococcus pneumoniae isolates in paediatric patients after the introduction of 13-valent conjugate vaccine in a nationwide surveillance study conducted in Japan in 2012-2014.
abstract: Pneumococcal infection in children is a major public health problem worldwide, including in Japan. The pneumococcal conjugate vaccine 7 (PCV7) was licensed for use in Japan in 2010 followed by PCV13 in 2013. This report includes the results of a nationwide surveillance of invasive pneumococcal disease (IPD) and non-IPD in paediatric patients from January 2012 to December 2014. We collected 343 isolates from 337 IPD patients and 286 isolates from 278 non-IPD patients. Of the IPD isolates, the most identified serotypes included 19A, 24F, and 15A. The prevalence of non-PCV13 serotype isolates increased significantly from 2012 to 2014 (51.6-71.4%, p=0.004). Serotypes 19A, 15A and 35B were highly non-susceptible to penicillin, and the rates of non-susceptible isolates from IPD patients to penicillin and cefotaxime significantly declined during the study period (p=0.029 and p=0.013, respectively). The non-susceptible rate to meropenem increased, particularly for serotype 15A. The IPD isolates comprised clonal complex (CC) 3111 (93.8% was serotype 19A) followed by CC2572 (81.5% was serotype 24F) and CC63 (97.1% was serotype 15A). CC3111, CC63 and CC156 (33.3% was serotype 23A, 28.6% was serotype 6B, and 14.3% was serotype 19A) were highly non-susceptible to penicillin. Of the non-IPD isolates, the most identified serotypes included 19A, 15A, and 3. In conclusion, the introduction of PCV7 and PCV13 resulted in increasing non-PCV13 serotypes and clones, including antimicrobial resistant serotypes 15A and CC63 (Sweden(15A)-25 clone).
authors.affiliation: Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nakano
authors.affiliation: Department of Clinical Research, National Hospital Organization Mie National Hospital, Tsu, Japan.
authors.forename: Takao
authors.initials: T
authors.lastname: Fujisawa
authors.affiliation: Department of Respiratory Medicine, Allergy and Rheumatology, Nagoya City University Graduate School of Medical Science, Nagoya, Japan. Electronic address: yutaka@med.nagoya-cu.ac.jp.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Ito
authors.affiliation: Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan.
authors.forename: Bin
authors.initials: B
authors.lastname: Chang
authors.affiliation: Department of Clinical Research, National Hospital Organization Mie National Hospital, Tsu, Japan.
authors.forename: Shigeru
authors.initials: S
authors.lastname: Suga
authors.affiliation: Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Taro
authors.initials: T
authors.lastname: Noguchi
authors.affiliation: Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Yamamoto
authors.affiliation: Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Yasufumi
authors.initials: Y
authors.lastname: Matsumura
authors.affiliation: Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Miki
authors.initials: M
authors.lastname: Nagao
authors.affiliation: Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Shunji
authors.initials: S
authors.lastname: Takakura
authors.affiliation: Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Ohnishi
authors.affiliation: Department of Paediatrics, National Hospital Organization Mie National Hospital, Tsu, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Ihara
authors.affiliation: Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ichiyama
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D024881:Drug Resistance, Bacterial; D062665:Epidemiological Monitoring; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007564:Japan / Q000453:epidemiology; D008297:Male; D017720:Molecular Epidemiology; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000382:microbiology* / Q000517:prevention & control; D022242:Pneumococcal Vaccines / Q000008:administration & dosage* / Q000276:immunology; D011446:Prospective Studies; D065288:Serogroup; D013296:Streptococcus pneumoniae / Q000145:classification* / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification
chemical_list: C538862:13-valent pneumococcal vaccine; D022242:Pneumococcal Vaccines
keywords: Invasive pneumococcal disease; Meropenem resistance; Nation-wide surveillance; PCV13; Paediatric; Streptococcus pneumoniae; Sweden(15A)-25 clone