Molecular analysis of fluoroquinolone-resistance in Escherichia coli on the aspect of gyrase and multiple antibiotic resistance (mar) genes.
10.3349/ymj.1998.39.6.534
- Author:
Yoon Hee PARK
1
;
Jin Hong YOO
;
Dong Ho HUH
;
Yoon Kyung CHO
;
Jung Hyun CHOI
;
Wan Shik SHIN
Author Information
1. Division of Infectious Diseases, Department of Internal Medicine, College of Medicine, The Catholic University of Korea. mogul@mail.hitel.net
- Publication Type:Original Article
- Keywords:
Fluoroquinolone-resistant E. coli;
marR;
mar mutation;
gyrA
- MeSH:
Ciprofloxacin/pharmacology*;
DNA Topoisomerase (ATP-Hydrolysing)/genetics*;
Drug Resistance, Microbial/genetics*;
Drug Resistance, Multiple/genetics*;
Escherichia coli/genetics;
Escherichia coli/drug effects*;
Human;
Mutation/physiology
- From:Yonsei Medical Journal
1998;39(6):534-540
- CountryRepublic of Korea
- Language:English
-
Abstract:
We analyzed the fluoroquinolone resistance mechanism of 28 isolates of ciprofloxacin-resistant E. coli from patients who received ciprofloxacin as a regimen of a selective gut decontamination. Isolates distinctive by infrequent restriction site polymerase chain reaction (IRS-PCR) were subjected to Hinf I restriction fragment length polymorphism analysis, single-stranded conformation polymorphism (SSCP), and nucleotide sequencing of the quinolone resistance determining region (QRDR) in gyrA. Double mutations in QRDR of gyrA (Ser83 Leu and Asp87Asn) were found from most of the strains. Nucleotide sequencing of the marR locus showed that 18 out of 28 (64%) ciprofloxacin-resistant E. coli strains had three types of base change in marR loci: a double-base change at nucleotides 1628 and 1751, or 1629 and 1751: and a single-base change at 1751. However, all the mutated strains showed no tolerance to cyclohexane test, suggesting the mutation in the marR region had no influence on overexpression of the MarA protein. In conclusion, mutation in gyrA was the main mechanism of ciporfloxacin resistance in E. coli from patients with selective gut decontamination. Therefore, mutation in the mar region did not influence the levels of ciprofloxacin resistance in our isolates.
