Random colony selection versus colony morphology for detection of multiple pneumococcal serotypes in nasopharyngeal swabs

Pediatr Infect Dis J. 2008 Feb;27(2):178-80. doi: 10.1097/INF.0b013e31815bb6c5.


Detection of multiple serotype carriage is important in understanding pneumococcal epidemiology. We compared random selection of 4 pneumococcal colonies per swab with selection by colony morphology. Multiple serotypes were detected in 20% of 98 swabs; 14% by morphology and 17% by random selection. Selection by morphology was more efficient per colony, but underestimated the true rate of multiple carriage.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carrier State
  • Humans
  • Nasopharynx / microbiology*
  • Pneumococcal Infections / microbiology*
  • Serotyping*
  • Streptococcus pneumoniae / classification*
  • Streptococcus pneumoniae / isolation & purification*