Whole Genome Sequencing of 39 Invasive Streptococcus pneumoniae Sequence Type 199 Isolates Revealed Switches from Serotype 19A to 15B

• Published in: PloS one Vol. 12; no. 1; p. e0169370
• Main Authors: Makarewicz, Oliwia, Lucas, Marie, Brandt, Christian, Herrmann, Leonie, Albersmeier, Andreas, Rückert, Christian, Blom, Jochen, Goesmann, Alexander, van der Linden, Mark, Kalinowski, Jörn, Pletz, Mathias W.
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 03.01.2017; Public Library of Science (PLoS)
• Subjects: Acids; Adolescent; Adult; Amino Acid Substitution; Analysis; Anti-Infective Agents - pharmacology; Antibiotics; Antimicrobial agents; Base Composition - genetics; Base Sequence; Bioinformatics; Biology; Biology and Life Sciences; Child; Child, Preschool; Cluster Analysis; Disease control; DNA sequencing; Drug Resistance, Bacterial - drug effects; Ear diseases; Epidemiology; Gene sequencing; Genetic aspects; Genome Size; Genomes; Gram-positive bacteria; Humans; Immunization; Infant; Infectious diseases; Medicine and Health Sciences; Mutation; Nucleotide sequence; Penicillin; People and Places; Phylogeny; Pneumococcal infections; Sequence Analysis, DNA; Serotypes; Serotyping; Streptococcus infections; Streptococcus pneumoniae; Streptococcus pneumoniae - classification; Streptococcus pneumoniae - drug effects; Streptococcus pneumoniae - genetics; Streptococcus pneumoniae - isolation & purification; Switches; Vaccines; Virulence; Virulence (Microbiology); Virulence factors; Young Adult; United States
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0169370

Streptococcus pneumoniae is a major pathogen that causes different invasive pneumococcal diseases (IPD). The pneumococcal polysaccharide capsule is a main virulence factor. More than 94 capsule types have been described, but only a limited number of capsule types accounted for the majority of IPD cases before the introduction of pneumococcal vaccines. After the introduction of the conjugated pneumococcal vaccine PCV7, which covered the seven most frequent serotypes in IPD in the USA, an increase in IPD caused by non-vaccine serotypes was observed, and serotype 19A, which belongs to sequence type (ST) 199, was among the most prevalent STs. After the introduction of the extended vaccine PCV13, which includes serotype 19A, serogroup 15B/C increased in IPD. Therefore, whole genome sequences of 39 isolates of ST199 from Germany (collected between 1998 and 2011) with serotype 19A (n = 24) and serogroup 15B/C (n = 15) were obtained using an Illumina platform and were analysed to identify capsular switches within ST199. Two 19A to 15B/C serotype switch events were identified. Both events occurred before the introduction of PCV7, which indicates that a capsular switch from 19A to 15B among ST199 isolates is not unusual and is not directly linked to the vaccination. The observed serotype replacement appears to be the result of a vacant niche due to the displacement of vaccine serotypes that is now successfully occupied by ST199 clones.