Susceptibility and bactericidal activity of 8 oral quinolones against conventional-fluoroquinolone-resistant Streptococcus pneumoniae clinical isolates

ABSTRACT Neisseria gonorrhoeae strains with reduced susceptibility to cefixime (MICs, 0.25 to 0.5 μg/ml) were isolated from male urethritis patients in Tokyo, Japan, in 2000 and 2001. The resistance to cephems including cefixime and penicillin was transferred to a susceptible recipient, N. gonorrhoeae ATCC 19424, by transformation of the penicillin-binding protein 2 gene (penA) that had been amplified by PCR from a strain with reduced susceptibility to cefixime (MIC, 0.5 μg/ml). The sequences of penA in the strains with reduced susceptibilities to cefixime were different from those of other susceptible isolates and did not correspond to the reported N. gonorrhoeae penA gene sequences. Some regions in the transpeptidase-encoding domain in this penA gene were similar to those in the penA genes of Neisseria perflava (N. sicca), Neisseria cinerea, Neisseria flavescens, and Neisseria meningitidis. These results showed that a mosaic-like structure in the penA gene conferred reductions in the levels of susceptibility of N. gonorrhoeae to cephems and penicillin in a manner similar to that found for N. meningitidis and Streptococcus pneumoniae.

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Prevalence and Characterization of Macrolide Resistance in Clinical Isolates of Streptococcus pneumoniae and Streptococcus pyogenes from North America

Journal of Chemotherapy ◽

10.1080/1120009x.2002.11782349 ◽

2002 ◽

Vol 14 (sup3) ◽

pp. 25-30 ◽

Cited By ~ 9

Author(s):

D.J. Hoban

Keyword(s):

Streptococcus Pneumoniae ◽

North America ◽

Streptococcus Pyogenes ◽

Macrolide Resistance ◽

Clinical Isolates

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Bactericidal activity of levofloxacin, gatifloxacin, penicillin, meropenem and rokitamycin against Bacillus anthracis clinical isolates

Journal of Antimicrobial Chemotherapy ◽

10.1093/jac/dkg006 ◽

2002 ◽

Vol 50 (6) ◽

pp. 1059-1063 ◽

Cited By ~ 8

Author(s):

L. Drago

Keyword(s):

Bacillus Anthracis ◽

Bactericidal Activity ◽

Clinical Isolates

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Synergistic Activities of Moxifloxacin Combined with Piperacillin-Tazobactam or Cefepime against Klebsiella pneumoniae, Enterobacter cloacae, and Acinetobacter baumannii Clinical Isolates

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.48.3.1055-1057.2004 ◽

2004 ◽

Vol 48 (3) ◽

pp. 1055-1057 ◽

Cited By ~ 13

Author(s):

Rose Jung ◽

Maroof Husain ◽

Michael K. Choi ◽

Douglas N. Fish

Keyword(s):

Klebsiella Pneumoniae ◽

Acinetobacter Baumannii ◽

Bactericidal Activity ◽

Enterobacter Cloacae ◽

Clinical Isolates ◽

Time Kill

ABSTRACT The bactericidal activity of moxifloxacin alone and in combination with cefepime or piperacillin-tazobactam against clinical isolates of Klebsiella pneumoniae, Enterobacter cloacae, and Acinetobacter baumannii was evaluated by using time-kill methods and antimicrobial concentrations of one-half and one times the MIC. Synergy was observed in 58 to 88% of the strains and resulted in bactericidal activity against 60 to 100% of the strains. Combinations including moxifloxacin demonstrated enhanced bactericidal activity compared with that of either agent tested alone.

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