The molecular epidemiology of penicillin-resistant Streptococcus pneumoniae in the United States, 1994-2000

Clin Infect Dis. 2002 Feb 1;34(3):330-9. doi: 10.1086/338065. Epub 2001 Dec 17.


The genetic relatedness of 672 penicillin-resistant isolates of Streptococcus pneumoniae (PRSP) recovered during national surveillance studies conducted in the United States during the periods of 1994-1995, 1997-1998, and 1999-2000 was determined by use of pulsed-field gel electrophoresis (PFGE). Overall, 104 different PFGE types were elucidated. For all study periods combined, the 12 most prevalent PFGE types included >75% of all isolates, and 5 types were closely related to widespread clones (Spain(23F)-1, France(9V)-3, Spain(6B)-2, Tennessee(23F)-4, and Taiwan(19F)-14). From 1994-1995 to 1999-2000, 3 major PFGE types (not closely related to 16 recognized clones) increased in prevalence. Multidrug resistance was identified among 96%-100% of the isolates in 9 of 12 predominant PFGE types. The prevalence of erythromycin resistance increased within 4 major PFGE types. These observations support the hypothesis that the dominant factor in the emergence of PRSP in the United States during the 1990s has been human-to-human spread of relatively few clonal groups that harbor resistance determinants to multiple classes of antibiotics.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Anti-Bacterial Agents / pharmacology
  • Child
  • Electrophoresis, Gel, Pulsed-Field
  • Erythromycin / pharmacology
  • Gene Frequency
  • Humans
  • Microbial Sensitivity Tests
  • Penicillin Resistance / genetics*
  • Pneumonia, Pneumococcal / epidemiology
  • Pneumonia, Pneumococcal / microbiology
  • Seasons
  • Serotyping
  • Streptococcus pneumoniae / drug effects
  • Streptococcus pneumoniae / genetics*
  • United States / epidemiology


  • Anti-Bacterial Agents
  • Erythromycin