Genetic profiles and antimicrobial resistance of Streptococcus pneumoniae non-PCV10 serotype isolates recovered from meningitis cases in Salvador, Brazil

J Med Microbiol. 2016 Oct;65(10):1164-1170. doi: 10.1099/jmm.0.000346. Epub 2016 Sep 2.

Abstract

In 2010, the 10-valent pneumococcal conjugate vaccine (PCV10) was introduced into the Brazilian childhood vaccination programme. Concerns have been raised that non-vaccine serotypes could increase in prevalence and reduce the benefits of vaccination; therefore, we examined non-PCV10 isolates recovered from meningitis during pre- (January 2008-May 2010) and post-vaccine (June 2010-December 2012) periods. Surveillance for pneumococcal meningitis was established at the Reference Hospital of Infectious Diseases in Salvador, Brazil. Serotypes were determined by multiplex PCR and/or Quellung reaction. Antimicrobial susceptibility testing was conducted by E-test and broth microdilution. Genotyping used PFGE and multi-locus sequence typing. A total of 148 cases of meningitis were identified from January 2008 to December 2012, 77 (52 %) of which were due to non-PCV10 isolates, with 50 (52.1 %) from pre-vaccine and 27 (52 %) from post-vaccine periods. In the post-vaccine period, the non-PCV10 serotypes 12F (n=6; 22.2 %), 10A (n=3; 11.1 %), 15B (n=2; 7.4 %) and 18B (n=2; 7.4 %) were the most prevalent. Forty-three isolates (55.8 %) were non-susceptible to one or more antibiotics. Non-susceptibility to penicillin was observed among serotypes 19A (three isolates), 9N (one isolate) and 12F (one isolate). PFGE and multi-locus sequence typing results demonstrated a wide genetic diversity among the isolates. During the early period following PCV10 introduction, no obvious emergence of a particular serotype was evident among non-PCV10 strains. This study underscores the importance of monitoring any changes among non-PCV10 cases after the introduction of PCV10.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Brazil / epidemiology
  • Child
  • Child, Preschool
  • Drug Resistance, Bacterial*
  • Electrophoresis, Gel, Pulsed-Field
  • Female
  • Genetic Variation
  • Genotype*
  • Hospitals
  • Humans
  • Infant
  • Male
  • Meningitis, Pneumococcal / epidemiology
  • Meningitis, Pneumococcal / microbiology*
  • Microbial Sensitivity Tests
  • Middle Aged
  • Molecular Epidemiology
  • Multilocus Sequence Typing
  • Multiplex Polymerase Chain Reaction
  • Pneumococcal Vaccines / administration & dosage
  • Pneumococcal Vaccines / immunology
  • Serogroup*
  • Serotyping
  • Streptococcus pneumoniae / classification*
  • Streptococcus pneumoniae / drug effects*
  • Streptococcus pneumoniae / genetics
  • Streptococcus pneumoniae / isolation & purification
  • Young Adult

Substances

  • 10-valent pneumococcal vaccine
  • Pneumococcal Vaccines