Dose-related selection of fluoroquinolone-resistant Escherichia coli
| Autor: | Otto Cars, Linda L. Marcusson, Diarmaid Hughes, Sara K. Olofsson, Ann Strömbäck |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
Microbiology (medical)
Cefotaxime medicine.drug_class Antibiotics Colony Count Microbial Microbial Sensitivity Tests Biology medicine.disease_cause Models Biological Microbiology Antibiotic resistance Moxifloxacin Drug Resistance Bacterial Escherichia coli medicine Pharmacology (medical) Norfloxacin Antibacterial agent Pharmacology Patient Selection Anti-Bacterial Agents Ciprofloxacin Infectious Diseases Mutation Fluoroquinolones medicine.drug |
| Zdroj: | Journal of Antimicrobial Chemotherapy. 60:795-801 |
| ISSN: | 1460-2091 0305-7453 |
| Popis: | The worldwide increase in antibiotic resistance is a concern for public health. When the appropriate antibiotic dosage is determined, the priorities are efficacy and toxicity. The aim of this thesis was to gain knowledge about the most efficient dosing regimens in order to minimize the emergence and selection of antibiotic-resistant mutants. We also wanted to assess the impact of antibiotic selective pressure and host to host transmission for the dissemination of resistance. Escherichia coli bacteria with different levels of cefotaxime susceptibility were competed in an in vitro kinetic model, demonstrating a complex selection of low-level resistance influenced e.g. by the time duration of selective concentrations and the rise of new mutants. We also constructed a mathematical model incorporating biologically relevant parameters and showed its usefulness when assessing the risks of resistance development. When E. coli populations with pre-existing fluoroquinolone-resistant mutants were exposed to simulated serum concentrations, several currently used doses of fluoroquinolones clearly enhanced the development and selection of resistance. The mutant prevention concentration (MPC) was measured for several E. coli isolates with different fluoroquinolone susceptibilities, and because of fluctuating antibiotic concentrations in the human body, the pharmacokinetics was considered when evaluating MPC. Results indicate that the area under the serum concentration time curve in relation to the MPC may be a useful predictor for emergence of resistance. In the commensal flora of healthy human couples we noted a high frequency of trimethoprim-resistant E. coli. There was also an extensive sharing and transmission of E. coli clones. Treating the female with trimethoprim reduced the number of intestinal E. coli which might have facilitated the transmission from the male partner. These findings suggest that the rate of transmission is high and effectively contributes to the spread of both susceptible and antibiotic-resistant E. coli in intrafamilial settings. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|