Distribution of capsular types and drug resistance patterns of invasive pediatric Streptococcus pneumoniae isolates in Teheran, Iran

Int J Infect Dis. 2017 Apr:57:21-26. doi: 10.1016/j.ijid.2017.01.020. Epub 2017 Jan 25.

Abstract

Objectives: To explore the serotype distribution and drug resistance patterns of invasive pneumococcal isolates from children under 5 years of age.

Methods: During a 32-month period, 585 clinical samples (including blood, cerebrospinal fluid (CSF), and synovial fluid) from children suspected of having meningitis, sepsis, pneumonia, or septic arthritis were analyzed using the BACTEC culture system. Positive cultures were examined using biochemical tests and lytA amplification for the identification of pneumococcal strains. The confirmed pneumococcal isolates were examined to determine capsular types using a modified sequential multiplex PCR and susceptibility to antimicrobial agents.

Results: Fifty-three pneumococcal isolates were detected in the 585 clinical samples: 21 (39.6%) blood samples and 32 (60.4%) CSF samples. The most frequent serotype was 23F (24.5%), followed by serotypes 19F (18.9%), 19A (7.5%), and 9V (7.5%). Twenty-one percent of pneumococcal isolates were penicillin-non-susceptible and serotype 19A was significantly associated with resistance to penicillin.

Conclusions: This study indicated that the 13-valent pneumococcal conjugate vaccine (PCV13) could cover the majority of the invasive pneumococcal isolates. Drug-resistant and multidrug-resistant Streptococcus pneumoniae strains are circulating in Iran. Therefore, public immunization of infants using PCV13 is recommended to reduce the incidence of pneumococcal disease and pneumococcal-resistant strains in Teheran.

Keywords: Invasive pneumococcal disease; Multidrug-resistant; Pediatric infections; Serotype distribution; Streptococcus pneumoniae.

MeSH terms

  • Anti-Bacterial Agents / pharmacology
  • Arthritis, Infectious / microbiology
  • Bacterial Capsules*
  • Child, Preschool
  • Female
  • Humans
  • Immunization
  • Incidence
  • Infant
  • Iran / epidemiology
  • Male
  • Multiplex Polymerase Chain Reaction
  • Penicillins / pharmacology
  • Pneumococcal Infections / epidemiology
  • Pneumococcal Infections / microbiology*
  • Pneumococcal Vaccines / administration & dosage
  • Sepsis / microbiology
  • Serotyping
  • Streptococcus pneumoniae / drug effects
  • Streptococcus pneumoniae / isolation & purification*
  • Streptococcus pneumoniae / physiology

Substances

  • 13-valent pneumococcal vaccine
  • Anti-Bacterial Agents
  • Penicillins
  • Pneumococcal Vaccines