title: Population structure and drug resistance patterns of emerging non-PCV-13 Streptococcus pneumoniae serotypes 22F, 15A, and 8 isolated from adults in Ontario, Canada.
abstract: The introduction of pneumococcal conjugate vaccines has led to the emergence of non-vaccine serotypes, which contributed to invasive pneumococcal disease in Canada and worldwide. A significant increase in the prevalence of non-13-valent pneumococcal conjugate vaccine (PCV-13)-included serotypes 22F, 15A, and 8 was observed from 2009 to 2013 in Ontario (all p values<0.01). In this study, whole genome sequencing was conducted on the 25 isolates of serotype 22F, seven of 15A and 10 of 8 to investigate the population structure and antibiotic resistance. All seven serotype 15A isolates were found to be multidrug resistant. From whole genome analysis, we observed recombination events among serotypes 22F, 15A and 8 populations. Serotype 22F (ST433) has emerged into two sub-populations, with 28% (7/25) exhibiting recombination events, and five also acquiring macrolide resistance as a result of recombination. This study enhances the knowledge on the molecular evolution of emerging non-PCV-13 vaccine serotype 22F, including acquisition of resistance genes through recombination events. It underpins the importance of whole genome sequencing in studying Streptococcus pneumoniae population structures and dynamics, and its utility in molecular surveillance.
authors.affiliation: Public Health Ontario, Toronto, Ontario, Canada. Electronic address: venkata.r.duvvuri@gmail.com.
authors.forename: Venkata R
authors.initials: VR
authors.lastname: Duvvuri
authors.affiliation: Public Health Ontario, Toronto, Ontario, Canada; University of Toronto, Toronto, Ontario, Canada. Electronic address: wayne.deng@oahpp.ca.
authors.forename: Xianding
authors.initials: X
authors.lastname: Deng
authors.affiliation: Public Health Ontario, Toronto, Ontario, Canada. Electronic address: sarah.teatero@oahpp.ca.
authors.forename: Sarah
authors.initials: S
authors.lastname: Teatero
authors.affiliation: Public Health Ontario, Toronto, Ontario, Canada. Electronic address: nadermemari@rogers.com.
authors.forename: Nader
authors.initials: N
authors.lastname: Memari
authors.affiliation: Public Health Ontario, Toronto, Ontario, Canada. Electronic address: taryn.athey@oahpp.ca.
authors.forename: Taryn
authors.initials: T
authors.lastname: Athey
authors.affiliation: Public Health Ontario, Toronto, Ontario, Canada; University of Toronto, Toronto, Ontario, Canada. Electronic address: nahuel.fittipaldi@oahpp.ca.
authors.forename: Nahuel
authors.initials: N
authors.lastname: Fittipaldi
authors.affiliation: Public Health Ontario, Toronto, Ontario, Canada; University of Toronto, Toronto, Ontario, Canada; The Hospital for Sick Children, Toronto, Ontario, Canada; Mount Sinai Hospital, Toronto, Ontario, Canada. Electronic address: jonathan.gubbay@oahpp.ca.
authors.forename: Jonathan B
authors.initials: JB
authors.lastname: Gubbay
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D019143:Evolution, Molecular; D016680:Genome, Bacterial; D006801:Humans; D018942:Macrolides / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D009864:Ontario / Q000453:epidemiology; D010802:Phylogeny; D011008:Pneumococcal Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000276:immunology / Q000382:microbiology; D022242:Pneumococcal Vaccines / Q000235:genetics / Q000276:immunology; D015995:Prevalence; D011995:Recombination, Genetic; D065288:Serogroup; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000145:classification / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification
chemical_list: C538862:13-valent pneumococcal vaccine; D000900:Anti-Bacterial Agents; D018942:Macrolides; D022242:Pneumococcal Vaccines
keywords: Antimicrobial resistance; Invasive pneumococcal disease; Non-PCV-13 serotypes; Streptococcus pneumoniae; Whole-genome sequencing