Emergence of a fluoroquinolone-resistant strain of Streptococcus pneumoniae in England

Alan Johnson*, Carmen Sheppard, S. J. Harnett, A. Birtles, Timothy Harrison, N. P. Brenwald, M. J. Gill, R. A. Walker, David Livermore, Robert George

*Corresponding author for this work

Research output: Contribution to journalReview articlepeer-review

28 Citations (Scopus)


Objective: To determine the epidemiological relationship between pneumococci of serotype 9V, with reduced susceptibility to ciprofloxacin, penicillin and erythromycin, referred to the Reference Laboratory during 1997-2001. Methods: Isolates were characterized by multilocus sequence typing (MLST), PFGE, and sequencing of parC and gyrA. Relevant clinical data were sought. Results: Forty-eight isolates were received from nine laboratories in England, but 35 (73%) were from one laboratory in Birmingham, and were mostly from elderly patients receiving ofloxacin or ciprofloxacin for respiratory infections. There were two quinolone resistance phenotypes, with ciprofloxacin, moxifloxacin and gemifloxacin MICs of 8-32, 0.5-1 and 0.125-0.25 mg/L, and 64-256, 4-16 and 1-4 mg/L, respectively. Each of three isolates from the former group had mutations in parC, whereas each of nine isolates from the more resistant group had mutations in both parC and gyrA. Several also had increased quinolone efflux. Typing of 27 quinolone-resistant isolates showed that eight were indistinguishable from the epidemic Spain9V-3 (ST156) clone, while the remainder belonged to a novel but related type (ST609), that differed from Spain9V-3 at 2/7 alleles (2 bp changes in aroE and 1 bp change in gdh). Both MLST types were represented among isolates with high- and low-level quinolone resistance. Three of five serotype 9V isolates from Birmingham, with reduced susceptibility to penicillin and erythromycin, and ciprofloxacin MICs of 1-2mg/L, belonged to MLST type ST609, while another was indistinguishable from the Spain9V-3 clone. Review of records of 32 patients from Birmingham indicated that some isolates were nosocomial, whereas others were acquired in the community. Conclusions: In the late 1990s, a quinolone-resistant strain, clonally related to Spain9V-3, emerged in England, principally in Birmingham.

Original languageEnglish
Pages (from-to)953-960
Number of pages8
JournalJournal of Antimicrobial Chemotherapy
Issue number6
Publication statusPublished - Dec 2003

Bibliographical note

Funding Information:
This publication made use of the multilocus sequence typing website (http://www.mlst.net) developed by Man-Suen Chan and David Aanensen and funded by the Wellcome Trust.


  • MLST
  • Quinolone resistance
  • Streptococcus pneumoniae


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