Knowing the entire sequence of the gene encoding the DNA gyrase Subunit A (gyrA) of Edwardsiella tarda could be very useful for confirming the role of gyrA in quinolone resistance. Degenerate primers for the amplification of gyrA were designed from consensus nucleotide sequences of gyrA from 9 different Gram-negative bacteria, including Escherichia coli. With these primers, DNA segments of the ...

BACKGROUND AND OBJECTIVES Gonococcal fluoroquinolone resistance is now a significant problem in Japan. We generated gonococcal mutants resistant to norfloxacin in vitro from norfloxacin sensitive isolates and analysed the contribution of three known mechanisms of quinolone resistance in Neisseria gonorrhoeae. MATERIALS AND METHODS Three clinical isolates of N gonorrhoeae susceptible to norflo...

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 g...

The MICs of ofloxacin for 743 strains of Escherichia coli isolated from 1988 to 1994 were determined by testing. The strains were from patients with urinary tract infections complicated by functional or anatomical disorders of the urinary tract. Those determined to be ofloxacin resistant (MIC, > or =12.5 microg/ml) comprised 3 of 395 strains (1.3%) from the 1988 to 1990 group, 2 of 166 strains ...

OBJECTIVES This study was aimed at characterizing the gyrA locus and determining its impact on fluoroquinolone susceptibility, DNA supercoiling degree and growth rate of Salmonella Typhimurium live vaccine strain vacT in comparison with its parent M415. Furthermore, the role of multiple drug resistance efflux in the susceptibility of vacT to fluoroquinolones and macrolides was investigated. M...

INTRODUCTION Campylobacter spp are the major cause of enteritis in humans and more than 90% of reported infections are caused by Campylobacter jejuni. Fluoroquinolones such as ciprofloxacin are the antibiotics of choice for treatment. An increase in the frequency of ciprofloxacin-resistant Campylobacter has been reported globally due to a single base mutation (C-257 to T) in codon 86 of the qui...

background: yersinia ruckeri is the etiological agent of enteric red mouth (erm) or yersinioisis disease, one of the important bacterial diseases in the cultured salmonids. objectives: the purpose of present study was detection of gyra gene (quinolone resistance) in the y. ruckeri bacterium. methods: in this study fish were evaluated in average size 8-12 cm from six rainbow trout farms in chaha...

Mutations in the quinolone resistance-determining regions (QRDR) in chromosomal gyrA and parC genes and fluoroquinolone susceptibility profiles were investigated in quinolone-resistant Enterobacteriaceae isolated from community and hospitalized patients in the Brazilian Southeast region. A total of 112 nalidixic acid-resistant enterobacterial isolates collected from 2000 to 2005 were investigat...

The mechanism of action of the quinolone analogs ofloxacin and S-25930, which are unusual because of the presence of a third ring with an asymmetric carbon, was studied. Drug-resistant strains of Escherichia coli were selected by serial passage in the presence of ofloxacin, and a mutation was mapped near the gyrA gene of DNA gyrase. DNA gyrase containing the A subunit purified from this strain ...

A fragment of the gyrA gene was sequenced from 34 isolates of Campylobacter coli, including 23 isolates resistant to ciprofloxacin. All ciprofloxacin-resistant isolates examined by DNA sequencing carried a point mutation at position Thr-86 on the gyrA gene product, involving the replacement of Thr-86 by Ile. A combined PCR-restriction fragment length polymorphism technique using RsaI was develo...