background: enterobacteriaceae are a large group of bacteria widely distributed in nature. escherichia coli is the most com­mon cause of urinary tract infection. two amino acid substitutions, in gyra, are commonly responsible for quinolone re­sistance in e. coli . the aim of this study was molecular survey of nalidixic acid resistance e.coli isolated from patients in the codones of 83 and 87 gy...

BACKGROUND The detection of mutations in the gyrA and gyrB genes in the Mycobacterium tuberculosis genome that have been demonstrated to confer phenotypic resistance to fluoroquinolones is the most promising technology for rapid diagnosis of fluoroquinolone resistance. METHODS In order to characterize the diversity and frequency of gyrA and gyrB mutations and to describe the global distributi...

A Pseudomonas aeruginosa AUST-02 strain sub-type (M3L7) has been identified in Australia, infects the lungs of some people with cystic fibrosis and is associated with antibiotic resistance. Multiple clonal lineages may emerge during treatment with mutations in chromosomally encoded antibiotic resistance genes commonly observed. Here we describe the within-host diversity and antibiotic resistanc...

AIM To analyse mutations in the gyrA and parC genes leading to possible increase in ciprofloxacin resistance (high MIC values for ciprofloxacin) in clinical isolates of Neisseria gonorrhoeae in Delhi, India. METHOD MIC of ciprofloxacin for 63 clinical isolates of N gonorrhoeae were examined by the Etest method. Subsequently, gyrA and parC genes of these isolates were amplified and sequenced f...

Ftorhinolony — osnovnaya gruppa preparatov, primenyaemyh dlya lecheniya tuberkuleza s mnozhestvennoj lekarstvennoj ustojchivost'yu (MLU-TB). Cel'yu issledovaniya bylo ocenit' raznoobrazie mutacij v gene gyrA, a takzhe ustanovit' associaciyu gyrA fenotipicheskoj k levofloksacinu i obshchim profilem ustojchivosti vozbuditelya. Issledovanie provedeno na diagnosticheskom materiale ot 2836 bol'nyh t...

DNA gyrase catalyses the adenosine triphosphate-dependent introduction of negative supercoils into DNA. The enzyme binds a DNA-segment at the so-called DNA-gate and cleaves both DNA strands. DNA extending from the DNA-gate is bound at the perimeter of the cylindrical C-terminal domains (CTDs) of the GyrA subunit. The CTDs are believed to contribute to the wrapping of DNA around gyrase in a posi...

strain with no parC mutations. This is consistent with previous findings that gyrA mutations are necessary for quinolone resistance, whereas parC mutations appear to be complementary, as resistant strains do not carry parC mutations alone. – 6 Some studies further suggest that additional parC mutations facilitate increasing levels of resistance, but our study did not support this. For example, ...

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. T...