Mutation frequency in antibiotic-resistant and -susceptible isolates of Streptococcus pneumoniae.
Development of multiple antibiotic resistance in Streptococcus pneumoniae typically involves either mutation or transformation at several well-separated chromosomal loci. We postulated that this series of genetic events would be more likely to occur in organisms with deficient DNA repair mechanisms. Investigation of 27 antibiotic-resistant or -susceptible clinical isolates of S. pneumoniae revealed a broad range of mutation frequencies, but no isolate was as mutable as a mismatch repair (MMR)-deficient laboratory isolate. No correlation was observed between antibiotic resistance and higher mutation frequency. Examination of a further 180 clinical isolates using a newly developed rapid screen method also failed to identify any isolates with a mutation frequency as high as the MMR-deficient control strain. We argue that there is currently no clear evidence of a distinct population of mutators among clinical pneumococci.
Queen Mary University of London, Barts and The London School of Medicine and Dentistry, Centre for Immunology and Infectious Disease, Blizard Institute of Cell and Molecular Science, 4 Newark Street, London E1 2AT, UK.
Stephanie K
SK
Henderson-Begg
Carmen L
CL
Sheppard
Robert C
RC
George
David M
DM
Livermore
Lucinda M C
LM
Hall
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial; D006801:Humans; D008826:Microbial Sensitivity Tests; D009154:Mutation; D011008:Pneumococcal Infections / Q000382:microbiology*; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification
D000900:Anti-Bacterial Agents