title: Emergence of Serotype IV Group B Streptococcus Adult Invasive Disease in Manitoba and Saskatchewan, Canada, Is Driven by Clonal Sequence Type 459 Strains.
abstract: Serotype IV group B Streptococcus (GBS) is emerging in Canada and the United States with rates as high as 5% of the total burden of adult invasive GBS disease. To understand this emergence, we studied the population structure and assessed the antimicrobial susceptibility of serotype IV isolates causing adult invasive infection in Manitoba and Saskatchewan, Canada, between 2010 and 2014. Whole-genome sequencing was used to determine multilocus sequence typing information and identify genes encoding antimicrobial resistance in 85 invasive serotype IV GBS strains. Antimicrobial susceptibility testing was performed by standard methods. Strain divergence was assessed using genome-wide single-nucleotide polymorphism analysis. Serotype IV strains were responsible for 16.9% of adult invasive GBS infections in Manitoba and Saskatchewan during the period. The majority of serotype IV isolates (89%) were clonally related, tetracycline-, erythromycin-, and clindamycin-resistant sequence type 459 (ST459) strains that possessed genes tetM and ermTR. Genome comparisons between ST459 and serotype V ST1 GBS identified several areas of recombination in an overall similar genomic background. Serotype IV ST459 GBS strains are expanding and causing a substantial percentage of adult invasive GBS disease. This emergence may be linked to the acquisition of resistance to tetracycline, macrolides, and lincosamides.
authors.affiliation: Public Health Ontario, Toronto, Ontario, Canada.
authors.forename: Sarah
authors.initials: S
authors.lastname: Teatero
authors.affiliation: Public Health Ontario, Toronto, Ontario, Canada.
authors.forename: Taryn B T
authors.initials: TB
authors.lastname: Athey
authors.affiliation: Cadham Provincial Laboratory, Department of Medical Microbiology, Winnipeg, Manitoba, Canada.
authors.forename: Paul
authors.initials: P
authors.lastname: Van Caeseele
authors.affiliation: Saskatchewan Disease Control Laboratory, Regina, Saskatchewan, Canada.
authors.forename: Greg
authors.initials: G
authors.lastname: Horsman
authors.affiliation: Saskatchewan Disease Control Laboratory, Regina, Saskatchewan, Canada.
authors.forename: David C
authors.initials: DC
authors.lastname: Alexander
authors.affiliation: Public Health Ontario, Toronto, Ontario, Canada Department of Microbiology, Mount Sinai Hospital, Toronto, Ontario, Canada Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Roberto G
authors.initials: RG
authors.lastname: Melano
authors.affiliation: Public Health Ontario, Toronto, Ontario, Canada.
authors.forename: Aimin
authors.initials: A
authors.lastname: Li
authors.affiliation: Section of Infectious Diseases, Department of Pediatrics, Texas Children's Hospital, and Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Anthony R
authors.initials: AR
authors.lastname: Flores
authors.affiliation: Department of Infectious Diseases, Division of Internal Medicine, MD Anderson Cancer Center, Houston, Texas, USA.
authors.forename: Samuel A
authors.initials: SA
authors.lastname: Shelburne
authors.affiliation: Department of Microbiology, Mount Sinai Hospital, Toronto, Ontario, Canada Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Allison
authors.initials: A
authors.lastname: McGeer
authors.affiliation: National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada.
authors.forename: Walter
authors.initials: W
authors.lastname: Demczuk
authors.affiliation: National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada.
authors.forename: Irene
authors.initials: I
authors.lastname: Martin
authors.affiliation: Public Health Ontario, Toronto, Ontario, Canada Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada nahuel.fittipaldi@oahpp.ca.
authors.forename: Nahuel
authors.initials: N
authors.lastname: Fittipaldi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D016470:Bacteremia / Q000453:epidemiology* / Q000382:microbiology; D016000:Cluster Analysis; D024881:Drug Resistance, Bacterial; D005260:Female; D016680:Genome, Bacterial; D005838:Genotype; D006801:Humans; D008297:Male; D008350:Manitoba / Q000453:epidemiology; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D008969:Molecular Sequence Data; D058885:Multilocus Sequence Typing; D010802:Phylogeny; D012525:Saskatchewan / Q000453:epidemiology; D065288:Serogroup; D013290:Streptococcal Infections / Q000453:epidemiology* / Q000382:microbiology; D013292:Streptococcus agalactiae / Q000145:classification* / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents