title: Major related sets of antibiotic-resistant Pneumococci in the United States as determined by pulsed-field gel electrophoresis and pbp1a-pbp2b-pbp2x-dhf restriction profiles.
abstract: To assess the genetic diversity of pneumococci causing serious disease within the United States, restriction profiles of 3 penicillin-binding protein (PBP)-gene amplicons and the dhf amplicon were examined in 241 recent sterile-site isolates from 7 population centers. This analysis provided markers useful for epidemiologic studies and was generally predictive of resistances to beta-lactam antibiotics and trimethoprim-sulfamethoxazole. Eight pulsed-field gel electrophoresis (PFGE) types, each representing 3-40 isolates, accounted for 134 of the 144 beta-lactam-resistant pneumococci (MICs >/=1 microgram/mL for penicillin, cefotaxime, or both). Five of these PFGE types contained subtypes highly related to subtypes of previously characterized pneumococcal clones. Within 4 of these PFGE types, the major composite PBP gene-dhf profile was highly related to the composite profile from the previously characterized related clone. Eight capsular serotypes were found among the 144 beta-lactam-resistant pneumococci. Divergent capsular types among isolates with identical PBP gene-dhf profiles and related PFGE types indicated several instances of capsular serotype switching.
authors.affiliation: National Center for Infectious Diseases, Respiratory Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
authors.forename: G
authors.initials: G
authors.lastname: Gherardi
authors.forename: C G
authors.initials: CG
authors.lastname: Whitney
authors.forename: R R
authors.initials: RR
authors.lastname: Facklam
authors.forename: B
authors.initials: B
authors.lastname: Beall
mesh_terms: D000595:Amino Acid Sequence; D019881:Aminoacyltransferases; D016667:Bacterial Capsules; D001426:Bacterial Proteins; D002352:Carrier Proteins / Q000235:genetics*; D002439:Cefotaxime / Q000494:pharmacology; D002511:Cephalosporins / Q000494:pharmacology; D004352:Drug Resistance, Microbial / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D005812:Genes, Switch; D005838:Genotype; D006602:Hexosyltransferases; D006801:Humans; D007769:Lactams / Q000494:pharmacology*; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D002267:Muramoylpentapeptide Carboxypeptidase / Q000235:genetics*; D010403:Penicillin Resistance / Q000235:genetics; D046915:Penicillin-Binding Proteins; D010458:Peptidyl Transferases; D011008:Pneumococcal Infections / Q000235:genetics*; D011237:Predictive Value of Tests; D017386:Sequence Homology, Amino Acid; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000145:classification / Q000187:drug effects* / Q000235:genetics; D013762:Tetrahydrofolate Dehydrogenase / Q000235:genetics*; D015662:Trimethoprim, Sulfamethoxazole Drug Combination / Q000494:pharmacology*; D014481:United States; D018440:beta-Lactam Resistance / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D002511:Cephalosporins; D007769:Lactams; D046915:Penicillin-Binding Proteins; D015662:Trimethoprim, Sulfamethoxazole Drug Combination; D013762:Tetrahydrofolate Dehydrogenase; D019881:Aminoacyltransferases; C478701:penicillin-binding protein 2b, Streptococcus; D010458:Peptidyl Transferases; D006602:Hexosyltransferases; D002267:Muramoylpentapeptide Carboxypeptidase; D002439:Cefotaxime