In this study, the contributions of different resistance mechanisms in Pseudomonas aeruginosa isolates were investigated among burned patients. The real-time reverse transcription polymerase chain reaction was performed to determine the expression level of mexY, ampC, and oprD for isolates. Also the isolates were typed by multilocus sequence typing (MLST). Seventy-five per cent of clinical isol...

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 ...

We report here the first case of a carbapenem-resistant Pseudomonas aeruginosa clinical isolate harboring the insertion sequence (IS) element ISPa1328 in the oprD gene in an idiopathic pulmonary fibrosis patient in France previously treated with imipenem.

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...

The modulating effect of N-acetylcysteine (NAC) on the activity of different antibiotics has been studied in Pseudomonas aeruginosa. Our results demonstrate that, in contrast to previous reports, only the activity of imipenem is clearly affected by NAC. MIC and checkerboard determinations indicate that the NAC-based modulation of imipenem activity is dependent mainly on OprD. SDS-PAGE of outer ...

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...

In contrast with most bacteria which possess two type II topoisomerases (topoisomerase IV and DNA gyrase), Mycobacterium tuberculosis possesses only one, DNA gyrase, which is functionally a hybrid enzyme. Functional differences between the two type IIA topoisomerases are thought to be specified by a CTD (C-terminal DNA-binding domain), which controls DNA recognition. To explore the molecular me...