Emergence of serotype 19AStreptococcus pneumoniaeafter PCV10 associated with a ST320 in adult population, in Porto Alegre, Brazil

• DOI: 10.1017/s0950268819000013
• Publication Date: 2019-02-22T14:25:50Z
• Authors: M.P. Mott; J. Caierão; G.R. Cunha; M.M. Del Maschi; K. Pizzutti; P. d'Azevedo; C.A.G. Dias
• Keywords: Multilocus sequence typing; Etest; Pneumococcal Conjugate Vaccine

Abstract Use of pneumococcal conjugate vaccines has caused emergence non-vaccine serotypes. No Brazilian data specifically about serotype 19A are available. We aimed to evaluate the frequency occurrence, susceptibility profile and molecular epidemiology before after vaccine introduction in Brazil. Pneumococcal identification was performed by conventional method. Strain determined multiplex polymerase chain reaction (PCR) and/or Quellung reaction. Resistance Etest ® PCR determine presence macrolide resistance genes, erm B mef A. Pneumococci were typed Multilocus Sequence Typing. Thirty-eight Streptococcus pneumoniae recovered, mostly from invasive diseases. Prevalence increased following vaccination (from 3.5% 8.1% after, p = 0.04196). Non-susceptibility most antimicrobials associated with clonal complex (CC)320. MLST showed nine different STs, which grouped one main CC: CC320 (63.9%). During post-vaccination era, this significantly 1.2% 2011 18.5% 2014 ( 0.00001), a concomitant decrease genetic variability: ST320 consistently predominated vaccine-introduction (61.1%). Overall, our results post-PCV10 increase 19A. This accompanied selection antimicrobial resistance.