Prevalence and clonal distribution of pcpA, psrP and Pilus-1 among pediatric isolates of Streptococcus pneumoniae

PLoS One. 2012;7(7):e41587. doi: 10.1371/journal.pone.0041587. Epub 2012 Jul 25.

Abstract

Streptococcus pneumoniae is the leading cause of vaccine-preventable deaths globally. The objective of this study was to determine the distribution and clonal type variability of three potential vaccine antigens: Pneumococcal serine-rich repeat protein (PsrP), Pilus-1, and Pneumococcal choline binding protein A (PcpA) among pneumococcal isolates from children with invasive pneumococcal disease and healthy nasopharyngeal carriers. We studied by Real-Time PCR a total of 458 invasive pneumococcal isolates and 89 nasopharyngeal pneumococcal isolates among children (total = 547 strains) collected in Barcelona, Spain, from January 2004 to July 2010. pcpA, psrP and pilus-1 were detected in 92.8%, 51.7% and 14.4% of invasive isolates and in 92.1%, 48.3% and 18% of carrier isolates, respectively. Within individual serotypes the prevalence of psrP and pilus-1 was highly dependent on the clonal type. pcpA was highly prevalent in all strains with the exception of those belonging to serotype 3 (33.3% in serotype 3 isolates vs. 95.1% in other serotypes; P<.001). psrP was significantly more frequent in those serotypes that are less apt to be detected in carriage than in disease; 58.7% vs. 39.1% P<.001. Antibiotic resistance was associated with the presence of pilus-1 and showed a negative correlation with psrP. These results indicate that PcpA, and subsequently Psrp and Pilus-1 together might be good candidates to be used in a next-generation of multivalent pneumococcal protein vaccine.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / genetics*
  • Carrier Proteins / genetics*
  • Child
  • Child, Preschool
  • Drug Resistance, Bacterial*
  • Female
  • Humans
  • Intracellular Signaling Peptides and Proteins
  • Male
  • Nasal Cavity / microbiology
  • Pharyngitis / genetics
  • Pharyngitis / microbiology
  • Pharyngitis / prevention & control
  • Pharynx / microbiology
  • Pneumococcal Infections / genetics*
  • Pneumococcal Infections / metabolism
  • Pneumococcal Infections / prevention & control
  • Pneumococcal Vaccines / genetics
  • Pneumococcal Vaccines / therapeutic use
  • Rhinitis / genetics
  • Rhinitis / microbiology
  • Rhinitis / prevention & control
  • Spain
  • Streptococcus pneumoniae / genetics*
  • Streptococcus pneumoniae / isolation & purification
  • Streptococcus pneumoniae / metabolism
  • Streptococcus pneumoniae / pathogenicity*

Substances

  • Bacterial Proteins
  • Carrier Proteins
  • Intracellular Signaling Peptides and Proteins
  • PcpA protein, Streptococcus
  • Pneumococcal Vaccines