title: Emergence of serogroup 15 Streptococcus pneumoniae of diverse genetic backgrounds following the introduction of pneumococcal conjugate vaccines in Hong Kong.
abstract: Serogroup 15 pneumococcal isolates from nasopharyngeal carriage of hospitalized children admitted to a teaching hospital in Hong Kong from April 2009 to September 2013 were characterized by pulse-field gel electrophoresis (PFGE), multilocus sequence typing, and antimicrobial non-susceptibility testing. The overall proportion of serogroup 15 isolates in the pre-PCV7 and post-PCV13 periods rose from 5.7% to 20.0%. The increase in trend for serotype 15B/C was statistically significant among children presented with pneumonia; bronchiolitis; upper respiratory tract infection; and febrile, non-respiratory diseases and for serotype 15A/F, among children with bronchiolitis and febrile, non-respiratory diseases. The predominant PFGE cluster of serotype 15B/C belonged to sequence type (ST) 199. Replacement of this more susceptible cluster (Ery and Tet non-susceptibilities of 32.2% and 25.4%) with the non-susceptible cluster, ST8859 (Ery and Tet non-susceptibilities of 91.7% and 87.5%) was noted. ST63 was the predominant serotype 15A cluster (Ery and Tet non-susceptibilities of 97.4% and 92.3%). Serogroup 15 subtypes have emerged in the post-PCV13 era, and these non-susceptible clusters warrant closer monitoring as candidates for incorporation to future pneumococcal vaccines.
authors.affiliation: Department of Microbiology, the Chinese University of Hong Kong, Hong Kong.
authors.forename: Veranja
authors.initials: V
authors.lastname: Liyanapathirana
authors.affiliation: Department of Paediatrics, Faculty of Medicine, the Chinese University of Hong Kong, Hong Kong.
authors.forename: E Anthony S
authors.initials: EA
authors.lastname: Nelson
authors.affiliation: Department of Microbiology, the Chinese University of Hong Kong, Hong Kong.
authors.forename: Irene
authors.initials: I
authors.lastname: Ang
authors.affiliation: Department of Microbiology, the Chinese University of Hong Kong, Hong Kong.
authors.forename: Reema
authors.initials: R
authors.lastname: Subramanian
authors.affiliation: Department of Microbiology, the Chinese University of Hong Kong, Hong Kong.
authors.forename: Helen
authors.initials: H
authors.lastname: Ma
authors.affiliation: Department of Microbiology, the Chinese University of Hong Kong, Hong Kong. Electronic address: margaretip@cuhk.edu.hk.
authors.forename: Margaret
authors.initials: M
authors.lastname: Ip
mesh_terms: D000293:Adolescent; D001988:Bronchiolitis / Q000382:microbiology; D002648:Child; D002675:Child, Preschool; D016521:Electrophoresis, Gel, Pulsed-Field; D006723:Hong Kong; D006801:Humans; D008826:Microbial Sensitivity Tests; D058885:Multilocus Sequence Typing; D011008:Pneumococcal Infections / Q000382:microbiology* / Q000517:prevention & control; D022242:Pneumococcal Vaccines / Q000627:therapeutic use*; D011023:Pneumonia, Staphylococcal / Q000382:microbiology; D065288:Serogroup; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D018074:Vaccines, Conjugate / Q000627:therapeutic use*
chemical_list: D022242:Pneumococcal Vaccines; D018074:Vaccines, Conjugate
keywords: Protein conjugate vaccine; Serogroup 15; Streptococcus pneumoniae