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.
Publication types
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Comparative Study
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Research Support, Non-U.S. Gov't
MeSH terms
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Amino Acid Sequence
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Aminoacyltransferases*
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Bacterial Capsules
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Bacterial Proteins*
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Carrier Proteins / genetics*
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Cefotaxime / pharmacology
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Cephalosporins / pharmacology
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Drug Resistance, Microbial / genetics
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Electrophoresis, Gel, Pulsed-Field
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Genes, Switch
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Genotype
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Hexosyltransferases*
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Humans
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Lactams / pharmacology*
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Molecular Epidemiology
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Molecular Sequence Data
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Muramoylpentapeptide Carboxypeptidase / genetics*
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Penicillin Resistance / genetics
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Penicillin-Binding Proteins
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Peptidyl Transferases*
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Pneumococcal Infections / genetics*
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Predictive Value of Tests
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Sequence Homology, Amino Acid
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Serotyping
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Streptococcus pneumoniae / classification
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Streptococcus pneumoniae / drug effects*
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Streptococcus pneumoniae / genetics
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Tetrahydrofolate Dehydrogenase / genetics*
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Trimethoprim, Sulfamethoxazole Drug Combination / pharmacology*
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United States
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beta-Lactam Resistance / genetics
Substances
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Bacterial Proteins
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Carrier Proteins
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Cephalosporins
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Lactams
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Penicillin-Binding Proteins
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Trimethoprim, Sulfamethoxazole Drug Combination
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Tetrahydrofolate Dehydrogenase
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Aminoacyltransferases
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penicillin-binding protein 2b, Streptococcus
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Peptidyl Transferases
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Hexosyltransferases
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Muramoylpentapeptide Carboxypeptidase
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Cefotaxime