Journal of Antimicrobial Chemotherapy, Vol 39, 609-615, Copyright © 1997 by The British Society for Antimicrobial Chemotherapy
LJ Piddock, YF Jin and MJ Everett
Two strains of Streptococcus pneumoniae, M4 (NCTC 7465, type strain) and M5
(clinical isolate), and their respective ciprofloxacin-resistant mutants,
M4/C1, M5/C1 and M5/C3, were evaluated. All mutants were stable after one
year's storage and all grew more slowly in Brain Heart Infusion broth than
the parent. The MICs of ciprofloxacin, sparfloxacin and tosufloxacin were
increased for the mutants of M4, whereas the mutants of M5 were less
susceptible to ciprofloxacin only. The optimal bactericidal concentration
(OBC) of each quinolone for all the strains was approximately ten-fold
greater than the MIC. The OBCs for the mutants were increased for
ciprofloxacin, but not for the other two quinolones. The DNA synthesis IC50
values of all quinolones correlated well with the MIC of each drug. All
quinolones accumulated rapidly within all five strains; 10 mM magnesium
chloride decreased the concentration of quinolone accumulated, but carbonyl
cyanide m- chlorophenyl hydrazone had no effect. Mutant strains M4/C1,
M5/C1 and M5/C3 accumulated less quinolone than their respective parent
strains. DNA sequencing of those regions of gyrA and gyrB corresponding to
the quinolone resistance-determining region in other bacteria did not
reveal any differences between the parent and mutant strains.
JOURNAL ARTICLE
Non-gyrA-mediated ciprofloxacin resistance in laboratory mutants of Streptococcus pneumoniae
Antimicrobial Agents Research Group, Department of Infection, University of Birmingham, UK. l.j.v.piddock@bham.ac.uk
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  L. Avrain, M. Garvey, N. Mesaros, Y. Glupczynski, M.-P. Mingeot-Leclercq, L. J. V. Piddock, P. M. Tulkens, R. Vanhoof, and F. Van Bambeke Selection of quinolone resistance in Streptococcus pneumoniae exposed in vitro to subinhibitory drug concentrations J. Antimicrob. Chemother., November 1, 2007; 60(5): 965 - 972. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. Marrer, A. T. Satoh, M. M. Johnson, L. J. V. Piddock, and M. G. P. Page Global Transcriptome Analysis of the Responses of a Fluoroquinolone-Resistant Streptococcus pneumoniae Mutant and Its Parent to Ciprofloxacin Antimicrob. Agents Chemother., January 1, 2006; 50(1): 269 - 278. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. J. V. Piddock and M. M. Johnson Accumulation of 10 Fluoroquinolones by Wild-Type or Efflux Mutant Streptococcus pneumoniae Antimicrob. Agents Chemother., March 1, 2002; 46(3): 813 - 820. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. M. Legg and A. J. Bint Will pneumococci put quinolones in their place? J. Antimicrob. Chemother., October 1, 1999; 44(4): 425 - 427. [Full Text] [PDF]
|
|
|
|
|
|
H. Fukuda and K. Hiramatsu Primary Targets of Fluoroquinolones in Streptococcus pneumoniae Antimicrob. Agents Chemother., February 1, 1999; 43(2): 410 - 412. [Abstract] [Full Text]
|
|
|
|
|
|
L. J. V. Piddock, M. Johnson, V. Ricci, and S. L. Hill Activities of New Fluoroquinolones against Fluoroquinolone-Resistant Pathogens of the Lower Respiratory Tract Antimicrob. Agents Chemother., November 1, 1998; 42(11): 2956 - 2960. [Abstract] [Full Text]
|
|