The gyrA quinolone resistance determining region was sequenced from 13 ciprofloxacin-resistant and 20 ciprofloxacin-susceptible Campylobacter jejuni isolates. All isolates resistant to ciprofloxacin had Thr-86-to-Ile mutations, a mutation frequently associated with the acquisition of resistance to fluoroquinolones. A mismatch amplification mutation assay (MAMA) PCR protocol was developed that d...

   Ciprofloxacin is one of the most widely used antibiotics for the treatment of several infections caused by Gram-negative bacteria, like E. coli. Changes in gyrA, encoding GyrA subunit of DNA gyrase, cause the resistance to ciprofloxacin. Some ciprofloxacin resistant gyrA mutants acquired constitutive expression of marRAB operon due to the gaining mutations in marR, a repressor of this operon...

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...

BACKGROUND AND OBJECTIVES The ciprofloxacin resistance of Klebsiella (K.) pneumoniae is mediated primarily through alterations in type II topoisomerase (gyrA) gene and plasmid-mediated quinolone resistance-conferring genes (qnr). This study aimed to define the prevalence of plasmid-mediated quinolone resistance-conferring genes (qnr) and type II topoisomerase (gyrA) alterations of a population ...

The control of water represents the safe key for fair and optimal use to protect resources due human activities, including untreated wastewater, which is considered a carrier large number antibiotic-resistant bacterial species. This study aimed investigate prevalence antibiotic-resistance E. coli in Tigris River by presence resistance genes aminoglycoside(qepA( ,quinolone (gyrA), sulfa drugs( d...

Vibrio parahaemolyticus causes seafood-borne gastroenteritis in humans. It is particularly important in Japan, where raw seafood is frequently consumed. Fluoroquinolone is one of the current drugs of choice for treating patients infected by V. parahaemolyticus because resistant strains are rarely found. To study a possible fluoroquinolone resistance mechanism in this organism, nucleotide sequen...

DNA gyrase is the only topoisomerase capable of introducing (-) supercoils into relaxed DNA. The C-terminal domain of the gyrase A subunit (GyrA-CTD) and the presence of a gyrase-specific 'GyrA-box' motif within this domain are essential for this unique (-) supercoiling activity by allowing gyrase to wrap DNA around itself. Here we report the crystal structure of Xanthomonas campestris GyrA-CTD...

Quinolones are a large and widely consumed class of synthetic drugs. Expanded-spectrum quinolones, like ciprofloxacin are highly effective against Gram-negative bacteria, especially Escherichia coli. In E. coli the major target for quinolones is DNA gyrase. This enzyme is composed of two subunits, GyrA and GyrB encoding by gyrA and gyrB, respectively. Mutations in either of these genes cause qu...

   Ciprofloxacin is one of the most widely used antibiotics for the treatment of several infections caused by Gram-negative bacteria, like E. coli. Changes in gyrA, encoding GyrA subunit of DNA gyrase, cause the resistance to ciprofloxacin. Some ciprofloxacin resistant gyrA mutants acquired constitutive expression of marRAB operon due to the gaining mutations in marR, a repressor of this operon...