The molecular epidemiology of penicillin-resistant Streptococcus pneumoniae in the United States, 1994-2000.
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.
Richter
S S
SS
Medical Microbiology Division, Department of Pathology, University of Iowa College of Medicine, Iowa City, IA 52242, USA. sandra-richter@uiowa.edu
Heilmann
K P
KP
Coffman
S L
SL
Huynh
H K
HK
Brueggemann
A B
AB
Pfaller
M A
MA
Doern
G V
GV
D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002648:Child; D016521:Electrophoresis, Gel, Pulsed-Field; D004917:Erythromycin / Q000494:pharmacology; D005787:Gene Frequency; D006801:Humans; D008826:Microbial Sensitivity Tests; D010403:Penicillin Resistance / Q000235:genetics*; D011018:Pneumonia, Pneumococcal / Q000453:epidemiology / Q000382:microbiology; D012621:Seasons; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000187:drug effects / Q000235:genetics*; D014481:United States / Q000453:epidemiology
D000900:Anti-Bacterial Agents; D004917:Erythromycin