Mutation frequency in antibiotic-resistant and -susceptible isolates of Streptococcus pneumoniae

Henderson-Begg, Stephanie K.; Sheppard, Carmen L.; George, Robert C.; Livermore, David M.; Hall, Lucinda M.C.

doi:10.1016/j.ijantimicag.2009.12.015

« Previous Next »International Journal of Antimicrobial Agents
Volume 35, Issue 4 , Pages 342-346, April 2010

Mutation frequency in antibiotic-resistant and -susceptible isolates of Streptococcus pneumoniae

Stephanie K. Henderson-Begg
- 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
- Present address: University of East London, School of Health & Biosciences, Romford Road, Stratford, London E15 4LZ, UK.
Carmen L. Sheppard
- Respiratory and Systemic Infection Laboratory, Centre for Infections, Health Protection Agency, 61 Colindale Avenue, London NW9 5EQ, UK
Robert C. George
- Respiratory and Systemic Infection Laboratory, Centre for Infections, Health Protection Agency, 61 Colindale Avenue, London NW9 5EQ, UK
David M. Livermore
- Antibiotic Resistance Monitoring and Reference Laboratory, Centre for Infections, Health Protection Agency, 61 Colindale Avenue, London NW9 5EQ, UK
Lucinda M.C. Hall
- 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
- Corresponding author. Tel.: +44 207 882 2323; fax: +44 207 882 2181.

Received 19 November 2009; accepted 18 December 2009. published online 10 February 2010.

Abstract

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.

Keywords: Streptococcus pneumoniae, Mutation frequency, Antibiotic resistance, Hypermutability