title: Recent trends of antigenic variation in Bordetella pertussis isolates in Korea.
abstract: Pertussis is a representative vaccine-preventable disease. However, there have been recent outbreaks in countries where even higher vaccination against the disease. One reason is the emergence of antigenic variants, which are different to vaccine type. In Korea, reported cases have rapidly increased since 2009. Therefore, we analyzed genotype of strains isolated in 2011-2012 by multilocus sequence typing method. As expected, the genotype profiles of tested genes dramatically changed. The major sequence type changed from ST1 to ST2, and new sequence type (ST8) appeared. In the minimum spanning tree, recent isolates belonging to the ACC-I-ST3 subgroup were detected that were composed of ST2, ST3, and ST6. In particular, the ST2 frequency increased to 81%. The novel ST8 was linked to the increased frequency of ST2. In addition, toxic strains carrying the ptxP3 promoter type were confirmed. This ptxP3 type emerged from 2009 and its frequency had increased to 100% in 2012. Based on these results, it can be inferred that the genotypic changes in the currently circulating strains are strongly associated with the recent increasing of pertussis in Korea. Therefore, the surveillance system should be strengthened, and genetic characterization of the isolates should be expanded to the whole genome sequence level.
authors.affiliation: Division of Bacterial Respiratory Infections, Korea National Institute of Health, Osong, Korea.
authors.forename: So-Hyun
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Division of Bacterial Respiratory Infections, Korea National Institute of Health, Osong, Korea.
authors.forename: Jin
authors.initials: J
authors.lastname: Lee
authors.affiliation: Pathogen Resource TF, Korea National Institute of Health, Osong, Korea.
authors.forename: Hwa Young
authors.initials: HY
authors.lastname: Sung
authors.affiliation: Division of Antimicrobial Resistance, Korea National Institute of Health, Osong, Korea.
authors.forename: Jae Yon
authors.initials: JY
authors.lastname: Yu
authors.affiliation: Division of Bacterial Respiratory Infections, Korea National Institute of Health, Osong, Korea.
authors.forename: Seong Han
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Division of Bacterial Respiratory Infections, Korea National Institute of Health, Osong, Korea.
authors.forename: Mi Sun
authors.initials: MS
authors.lastname: Park
authors.affiliation: Division of Bacterial Respiratory Infections, Korea National Institute of Health, Osong, Korea.
authors.forename: Sang-Oun
authors.initials: SO
authors.lastname: Jung
mesh_terms: D000940:Antigenic Variation; D000941:Antigens / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001886:Bordetella pertussis / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D005798:Genes, Bacterial; D005838:Genotype; D006801:Humans; D037342:Pertussis Toxin / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic; D056910:Republic of Korea; D017422:Sequence Analysis, DNA; D014917:Whooping Cough / Q000276:immunology / Q000382:microbiology* / Q000473:pathology
chemical_list: D000941:Antigens; D001426:Bacterial Proteins; D037342:Pertussis Toxin
keywords: Antigenic Variation; Bordetella pertussis; Minimum Spanning Tree; Multilocus Sequence Typing; Pertussis Toxin; Pertussis Vaccine