Comparative in vitro activity of gatifloxacin, grepafloxacin, levofloxacin, moxifloxacin and trovafloxacin against 4151 Gram-negative and Gram-positive organisms

Blondeau, Joseph M; Laskowski, Roman A.; Bjarnason, Jaime; Stewart, Catherine

doi:10.1016/s0924-8579(99)00143-0

Cited by 91 publications

(50 citation statements)

References 19 publications

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confidence: 90%

“…On the basis of a breakpoint of Յ1 g/ml, 88 of the 108 selected mutants were inhibited by clinafloxacin, 65 were inhibited by gemifloxacin, 46 were inhibited by moxifloxacin, 32 were inhibited by gatifloxacin, 20 were inhibited by sparfloxacin, and 3 were inhibited by ciprofloxacin. This rank order of activity is in parallel with previous findings (2,4,7,19,20,26).On the basis of the results presented in Tables 1 to 3, none of the quinolones was associated with a clearly lower potential for resistance development, measured as an increase in MIC doubling dilutions, compared with the potential for resistance development of the other quinolones tested. On the basis of the limited available data, one must be cautious in drawing broad conclusions.…”

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confidence: 88%

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In Vitro Development of Resistance to Six Quinolones in Streptococcus pneumoniae, Streptococcus pyogenes , and Staphylococcus aureus

Boos

Mayer

Fischer

et al. 2001

Antimicrob Agents Chemother

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Streptococcus pneumoniae, Streptococcus pyogenes, and Staphylococcus aureus isolates were exposed to subinhibitory MICs of ciprofloxacin, sparfloxacin, gatifloxacin, moxifloxacin, clinafloxacin, and gemifloxacin during a 10-day period. Subculturing led to resistance development, regardless of the initial potencies of the quinolones. None of the quinolones was associated with a significantly slower rate of resistance development.Fluoroquinolone resistance in gram-positive cocci is related to mutations in the DNA gyrase and topoisomerase IV genes (8-12, 16, 23) and the active efflux of agents (1, 3, 13, 21-25, 31, 44). Because fluoroquinolones differ in both their target affinity (8,16,(33)(34)(35)(36)39) and their activation of efflux pumps (7,13,21,22,24,25,31,42), one can speculate that the phenotypic expression of quinolone resistance will also differ. Studies have shown that fluoroquinolone resistance can be selected for in pneumococci and staphylococci (5,6,37).In order to analyze the ability of newer fluoroquinolones to cause resistance development in Streptococcus pneumoniae, Streptococcus pyogenes, and Staphylococcus aureus, we repeatedly exposed six clinical strains of each species to ciprofloxacin, sparfloxacin, gatifloxacin, moxifloxacin, clinafloxacin, and gemifloxacin.Approximately 5 ϫ 10 7 CFU of each of the 18 strains was added to tubes containing 9.9 ml of appropriate broth containing antibiotic concentrations ranging from 3 doubling dilutions above to 3 doubling dilutions below the MIC of each of the six agents. The tubes were then incubated for 24 h at 37°C. Aliquots from the test tubes containing the highest drug concentration that permitted visible growth were used following a 1:100 dilution to inoculate a second set of serial drug dilutions. After overnight incubation, the bacteria were transferred again. Finally, after 10 serial transfers, the bacteria for which the MICs were the highest were collected, stored, and also subcultured on quinolone-free agar for 10 days to assess the stability of resistance.MICs were determined by the microdilution methodology according to NCCLS guidelines (29, 30). Ciprofloxacin MIC determinations were conducted in the presence and absence of reserpine (20 g/ml; tests were repeated three times) for all of the original isolates (n ϭ 18) as well as for all of the selected mutants (n ϭ 108) (7).S. pneumoniae and S. aureus isolates were analyzed before and after transfers for mutations in the quinolone-resistance determining regions (QRDRs) of parC or grlA and gyrA, respectively (19,40,41).The MIC results from subculturing as well as the mutations in the QRDRs of S. pneumoniae and S. aureus are summarized in the Tables 1 to 3. Subculturing with newer quinolones led to resistance development in all three species. This is in line with previous reports with regard to cephalosporins, macrolides, and older quinolones in pneumococci (5, 6, 37).Resistance was stable in all cases; i.e., the MICs for the 108 selected mutants remained within 1 doubling dilution after 10 tr...

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confidence: 90%

supporting

confidence: 88%

In Vitro Development of Resistance to Six Quinolones in Streptococcus pneumoniae, Streptococcus pyogenes , and Staphylococcus aureus

Boos

Mayer

Fischer

et al. 2001

Antimicrob Agents Chemother

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“…It has an antimicrobial activity against many Gram-positive and Gram-negative aerobic and anaerobic bacteria as well as atypical bacteria such as Chlamydia and Mycoplasma (Dalhoff et al, 1996;Bauernfeind, 1997;Goldstein et al, 1997;Edlund et al, 1998;Ackermann et al, 2000;Blondeau et al, 2000;Kleinkauf et al, 2001;Krasemann et al, 2001;Talan, 2001;Zhanel et al, 2002).…”

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confidence: 99%

Activity of moxifloxacin against Bacteroides fragilis and Escherichia coli in an in vitro pharmacokinetic/pharmacodynamic model employing pure and mixed cultures

Schaumann

Goldstein

Forberg

et al. 2005

Journal of Medical Microbiology

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The objective of this study was to determine the pharmacodynamic (PD) activity of moxifloxacin against four selected Bacteroides fragilis strains (three strains with low MICs and one strain with a high MIC) and two Escherichia coli strains (one strain with a low MIC and one strain with a high MIC) in a pharmacokinetic (PK) in vitro model in pure cultures as well as in mixed cultures. PK/PD assays of moxifloxacin were carried out with an initial maximum concentration of 4 . 0 mg l À1 and a half-life of 13 h. The E. coli strain with the low MIC was rapidly killed in both pure and mixed cultures in the in vitro PK/PD model, while the E. coli strain with the high MIC was not killed. None of the B. fragilis strains were rapidly killed in pure or mixed cultures. The bacterial numbers of the B. fragilis strains with low MICs were reduced by about one to two logs after 12 h in pure cultures. The presence of an E. coli strain with a low or a high MIC in the mixed culture reduced this effect even further.

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“…Gatifloxacin (GT) is a fourth generation fluoroquinolone, with a broad antibacterial spectrum, including a number of aerobic, anaerobic, gram positive bacteria, is was shown to be highly active against penicillin sensitive and resistant Streptococcus pneumoniae, Staphylococcus aureus, Streptococcus pyogenes and Streptococcus agalactiae and a number of gram-negative microorganisms [7]. The aim of the present study was to formulate bioadhesive periodontal gels of gatifloxacin with appropriate viscosity, spread ability, and release behavior so as to provide localized and prolonged drug release for better management of local periodontal infections.…”

Section: Introductionmentioning

confidence: 99%

Development and Physical Characterization of a Periodontal Bioadhesive Gel of Gatifloxacin

2017

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Objective: The aim of this study was to develop a bioadhesive gel of gatifloxacin for the treatment of periodontal diseases.Methods: Periodontal gels of gatifloxacin were prepared using different hydrophilic polymers such as carbopol 940 (CP 940), carboxymethyl cellulose (CMC) and hydroxypropylmethyl cellulose (HPMC) in varied concentrations, either alone or as a combination. The prepared gels were evaluated for their physical appearance, pH, drug content, viscosity, bioadhesiveness and in vitro drug release profile. The influence of the type and the concentration of polymer on the drug release as well as on viscosity and mucoadhesiveness of prepared gels were investigated. Results:The prepared gels showed acceptable physical properties concerning color, homogeneity, consistency, spreadability, and pH value. Using different polymer types at different concentrations, as well as different polymer combinations, play a significant role in the variation of overall characteristics of formulations. Increasing the concentration of polymer increased the viscosity as well as mucoadhesion, and reduced drug release rate. Formulation F 11 (1 % CP 940 and 5 % CMC) was selected as the formula of choice based on the data of various evaluation parameters such as pH, drug content, viscosity, spreadability and bioadhesion as well as its ability to show a prolonged drug release pattern. Conclusion:The obtained results show that a bioadhesive periodontal gel of gatifloxacin can be prepared using hydrophilic polymers, and by using a combination of polymers the viscosity, mucoadhesiveness, spreadability and release behavior can be optimized.

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Comparative in vitro activity of gatifloxacin, grepafloxacin, levofloxacin, moxifloxacin and trovafloxacin against 4151 Gram-negative and Gram-positive organisms

Cited by 91 publications

References 19 publications

In Vitro Development of Resistance to Six Quinolones in Streptococcus pneumoniae, Streptococcus pyogenes , and Staphylococcus aureus

In Vitro Development of Resistance to Six Quinolones in Streptococcus pneumoniae, Streptococcus pyogenes , and Staphylococcus aureus

Activity of moxifloxacin against Bacteroides fragilis and Escherichia coli in an in vitro pharmacokinetic/pharmacodynamic model employing pure and mixed cultures

Development and Physical Characterization of a Periodontal Bioadhesive Gel of Gatifloxacin

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