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.
Henderson-Begg
Stephanie K
SK
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.
Sheppard
Carmen L
CL
George
Robert C
RC
Livermore
David M
DM
Hall
Lucinda M C
LM
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