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Alteration in the GyrA subunit of DNA gyrase and the ParC subunit of DNA topoisomerase IV in quinolone-resistant clinical isolates of Staphylococcus epidermidis.

ABSTRACT: We examined 22 clinical isolates of Staphylococcus epidermidis to analyze the association of alterations in GyrA and ParC with fluoroquinolone resistance. The simultaneous presence of GyrA and ParC alterations was associated with a high level of fluoroquinolone resistance in the clinical isolates of S. epidermidis.

SUBMITTER: Li Z

PROVIDER: S-EPMC106039 | biostudies-literature | 1998 Dec

REPOSITORIES: biostudies-literature

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Alteration in the GyrA subunit of DNA gyrase and the ParC subunit of DNA topoisomerase IV in quinolone-resistant clinical isolates of Staphylococcus epidermidis.

Li Z Z Deguchi T T Yasuda M M Kawamura T T Kanematsu E E Nishino Y Y Ishihara S S Kawada Y Y

Antimicrobial agents and chemotherapy 19981201 12

We examined 22 clinical isolates of Staphylococcus epidermidis to analyze the association of alterations in GyrA and ParC with fluoroquinolone resistance. The simultaneous presence of GyrA and ParC alterations was associated with a high level of fluoroquinolone resistance in the clinical isolates of S. epidermidis. ...[more]

PMID: 9835531

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Alterations in the GyrA subunit of DNA gyrase and the ParC subunit of DNA topoisomerase IV associated with quinolone resistance in Enterococcus faecalis.

Project description:The gyrA and parC genes of 31 clinical isolates of Enterococcus faecalis, including fluoroquinolone-resistant isolates, were partially sequenced and analyzed for target alterations. Topoisomerase IV may be a primary target in E. faecalis, but high-level fluoroquinolone resistance was associated with simultaneous alterations in both GyrA and ParC.

| S-EPMC105429 | biostudies-literature

Alteration in the GyrA subunit of DNA gyrase and the ParC subunit of topoisomerase IV in Quinolone-resistant Shigella dysenteriae serotype 1 clinical isolates from Kolkata, India.

Project description: Not available

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ParC subunit of DNA topoisomerase IV of Streptococcus pneumoniae is a primary target of fluoroquinolones and cooperates with DNA gyrase A subunit in forming resistance phenotype.

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| S-EPMC163513 | biostudies-other

Alterations in topoisomerase IV and DNA gyrase in quinolone-resistant mutants of Mycoplasma hominis obtained in vitro.

Project description:Mycoplasma hominis mutants were selected stepwise for resistance to ofloxacin and sparfloxacin, and their gyrA, gyrB, parC, and parE quinolone resistance-determining regions were characterized. For ofloxacin, four rounds of selection yielded six first-, six second-, five third-, and two fourth-step mutants. The first-step mutants harbored a single Asp426-->Asn substitution in ParE. GyrA changes (Ser83-->Leu or Trp) were found only from the third round of selection. With sparfloxacin, three rounds of selection generated 4 first-, 7 second-, and 10 third-step mutants. In contrast to ofloxacin resistance, GyrA mutations (Ser83-->Leu or Ser84-->Trp) were detected in the first-step mutants prior to ParC changes (Glu84-->Lys), which appeared only after the second round of selection. Further analysis of eight multistep-selected mutants of M. hominis that were previously described (2) revealed that they carried mutations in ParE (Asp426-->Asn), GyrA (Ser83-->Leu) and ParE (Asp426-->Asn), GyrA (Ser83-->Leu) and ParC (Ser80-->Ile), or ParC (Ser80-->Ile) alone, depending on the fluoroquinolone used for selection, i.e., ciprofloxacin, norfloxacin, ofloxacin, or pefloxacin, respectively. These data indicate that in M. hominis DNA gyrase is the primary target of sparfloxacin whereas topoisomerase IV is the primary target of pefloxacin, ofloxacin, and ciprofloxacin.

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Project description:Mycoplasma gallisepticum enrofloxacin-resistant mutants were generated by stepwise selection in increasing concentrations of enrofloxacin. Alterations were found in the quinolone resistance-determining regions of the four target genes encoding DNA gyrase and topoisomerase IV from these mutants. This is the first description of such mutations in an animal mycoplasma species.

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Activities of gyrase and topoisomerase IV on positively supercoiled DNA.

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Crystal structures of Escherichia coli topoisomerase IV ParE subunit (24 and 43 kilodaltons): a single residue dictates differences in novobiocin potency against topoisomerase IV and DNA gyrase.

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| S-EPMC400558 | biostudies-literature

Sequencing of gyrase and topoisomerase IV quinolone-resistance-determining regions of Chlamydia trachomatis and characterization of quinolone-resistant mutants obtained In vitro.

Project description:The L2 reference strain of Chlamydia trachomatis was exposed to subinhibitory concentrations of ofloxacin (0.5 microg/ml) and sparfloxacin (0.015 microg/ml) to select fluoroquinolone-resistant mutants. In this study, two resistant strains were isolated after four rounds of selection. The C. trachomatis mutants presented with high-level resistance to various fluoroquinolones, particularly to sparfloxacin, for which a 1,000-fold increase in the MICs for the mutant strains compared to the MIC for the susceptible strain was found. The MICs of unrelated antibiotics (doxycycline and erythromycin) for the mutant strains were identical to those for the reference strain. The gyrase (gyrA, gyrB) and topoisomerase IV (parC, parE) genes of the susceptible and resistant strains of C. trachomatis were partially sequenced. A point mutation was found in the gyrA quinolone-resistance-determining region (QRDR) of both resistant strains, leading to a Ser83-->Ile substitution (Escherichia coli numbering) in the corresponding protein. The gyrB, parC, and parE QRDRs of the resistant strains were identical to those of the reference strain. These results suggest that in C. trachomatis, DNA gyrase is the primary target of ofloxacin and sparfloxacin.

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Cloning and nucleotide sequence of the DNA gyrase gyrA gene from Serratia marcescens and characterization of mutations in gyrA of quinolone-resistant clinical isolates.

Project description:The sequence of the DNA gyrase gyrA gene of Serratia marcescens ATCC 14756 was determined. An open reading frame of 2,640 nucleotides coding for a polypeptide with a calculated molecular mass of 97,460 was found, and its sequence complemented the sequence of an Escherichia coli gyrA temperature-sensitive mutation. Analysis of the PCR products of the quinolone resistance-determining regions of gyrA genes from six quinolone-resistant clinical isolates revealed a single amino acid substitution, Ser-83 to Arg or Asp-87 to Tyr, in all six mutants, suggesting that a mutational alteration in gyrA is a common mechanism of quinolone resistance in S. marcescens.

| S-EPMC105481 | biostudies-literature

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