title: Use of the 13-valent conjugate vaccine has the potential to eliminate pilus carrying isolates as causes of invasive pneumococcal disease.
abstract: We examined the distribution of the two pilus island loci (PI-1 and PI-2) in all pediatric invasive pneumococcal disease (IPD) isolates recovered in Portugal over the ten year period 1999-2008 (n=575). While 199 isolates (35%) harbored PI-2, only 98 isolates (17%) harbored PI-1. A decline of isolates carrying PI-1 was observed in the post 7-valent conjugate vaccine (PCV7) period since most PI-1 carrying isolates expressed PCV7 serotypes. On the other hand, the PI-2 increase in the post-PCV7 period was associated mostly with serotypes 1 and 7F. The overall proportion of piliated isolates declined in the period following PCV7 but quickly recovered to pre-PCV7 levels (50%). Only serotypes 19F and 19A contained isolates carrying simultaneously PI-1 and PI-2 and the proportion of isolates carrying both pilus islands remained stable and low. All PI-1 clades were represented in our collection and were associated with multiple serotypes. Over 99% of pilus island carrying isolates belonged to the 13-valent conjugate vaccine serotypes.
authors: Instituto de Microbiologia, Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal.
authors: Sandra I
authors: SI
authors: Aguiar
authors: José
authors: J
authors: Melo-Cristino
authors: Mário
authors: M
authors: Ramirez
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D010861:Fimbriae, Bacterial / Q000235:genetics / Q000276:immunology; D006801:Humans; D007231:Infant, Newborn; D008137:Longitudinal Studies; D011008:Pneumococcal Infections / Q000276:immunology / Q000382:microbiology* / Q000517:prevention & control*; D022242:Pneumococcal Vaccines / Q000627:therapeutic use*; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000145:classification / Q000166:cytology* / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification*; D018074:Vaccines, Conjugate / Q000627:therapeutic use
chemical_list: C538862:13-valent pneumococcal vaccine; D022242:Pneumococcal Vaccines; D018074:Vaccines, Conjugate