title: Clinical implications of pneumococcal serotypes: invasive disease potential, clinical presentations, and antibiotic resistance.
abstract: Streptococcus pneumoniae can asymptomatically colonize the nasopharynx and cause a diverse range of illnesses. This clinical spectrum from colonization to invasive pneumococcal disease (IPD) appears to depend on the pneumococcal capsular serotype rather than the genetic background. According to a literature review, serotypes 1, 4, 5, 7F, 8, 12F, 14, 18C, and 19A are more likely to cause IPD. Although serotypes 1 and 19A are the predominant causes of invasive pneumococcal pneumonia, serotype 14 remains one of the most common etiologic agents of non-bacteremic pneumonia in adults, even after 7-valent pneumococcal conjugate vaccine (PCV7) introduction. Serotypes 1, 3, and 19A pneumococci are likely to cause empyema and hemolytic uremic syndrome. Serotype 1 pneumococcal meningitis is prevalent in the African meningitis belt, with a high fatality rate. In contrast to the capsule type, genotype is more closely associated with antibiotic resistance. CC320/271 strains expressing serotype 19A are multidrug-resistant (MDR) and prevalent worldwide in the era of PCV7. Several clones of MDR serotype 6C pneumococci emerged, and a MDR 6D clone (ST282) has been identified in Korea. Since the pneumococcal epidemiology of capsule types varies geographically and temporally, a nationwide serosurveillance system is vital to establishing appropriate vaccination strategies for each country.
authors: Division of Infectious Diseases, Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea. infection@korea.ac.kr
authors: Joon Young
authors: JY
authors: Song
authors: Moon H
authors: MH
authors: Nahm
authors: M Allen
authors: MA
authors: Moseley
mesh_terms: D024901:Drug Resistance, Multiple, Bacterial; D004653:Empyema / Q000209:etiology; D006463:Hemolytic-Uremic Syndrome / Q000209:etiology; D006801:Humans; D008581:Meningitis / Q000209:etiology; D010538:Peritonitis / Q000209:etiology; D011008:Pneumococcal Infections / Q000150:complications / Q000276:immunology*; D011018:Pneumonia, Pneumococcal / Q000276:immunology; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000145:classification* / Q000472:pathogenicity
keywords: Bacterial Capsules; Pneumococcal Infections; Polysaccharides, Bacterial; Serotyping; Streptococcus pneumoniae