Clonal and serotype dynamics of serogroup 6 isolates causing invasive pneumococcal disease in Portugal: 1999-2012.
Although serogroup 6 was among the first to be recognized among Streptococcus pneumoniae, several new serotypes were identified since the introduction of pneumococcal conjugate vaccines (PCVs). A decrease of the 6B-2 variant among invasive pneumococcal disease (IPD), but not 6B-1, was noted post conjugate vaccine introduction, underpinned by a decrease of CC273 isolates. Serotype 6C was associated with adult IPD and increased in this age group representing two lineages (CC315 and CC395), while the same lineages expressed other serogroup 6 serotypes in children. Taken together, these findings suggest a potential cross-protection of PCVs against serotype 6C IPD among vaccinated children but not among adults. Serotype 6A became the most important serogroup 6 serotype in children but it decreased in adult IPD. No other serogroup 6 serotypes were detected, so available phenotypic or simple genotypic assays remain adequate for distinguishing serotypes within serogroup 6 isolates.
Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, Lisboa, Portugal.
Jorge
J
Diamantino-Miranda
Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, Lisboa, Portugal.
Sandra Isabel
SI
Aguiar
Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, Lisboa, Portugal.
João André
JA
Carriço
Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, Lisboa, Portugal.
José
J
Melo-Cristino
Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, Lisboa, Portugal.
Mário
http://orcid.org/0000-0002-4084-6233
M
Ramirez
D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D056738:Cross Protection / Q000276:immunology*; D000069443:Heptavalent Pneumococcal Conjugate Vaccine / Q000276:immunology*; D006801:Humans; D007153:Immunologic Deficiency Syndromes / Q000453:epidemiology* / Q000382:microbiology; D053592:Interleukin-1 Receptor-Associated Kinases; D008826:Microbial Sensitivity Tests; D058885:Multilocus Sequence Typing; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000382:microbiology; D022242:Pneumococcal Vaccines / Q000276:immunology*; D011174:Portugal / Q000453:epidemiology; D000081207:Primary Immunodeficiency Diseases; D065288:Serogroup; D013296:Streptococcus pneumoniae / Q000145:classification / Q000235:genetics* / Q000276:immunology* / Q000302:isolation & purification; D014611:Vaccination
C586648:10-valent pneumococcal conjugate vaccine; C538862:13-valent pneumococcal vaccine; D000900:Anti-Bacterial Agents; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D022242:Pneumococcal Vaccines; D053592:Interleukin-1 Receptor-Associated Kinases