Microorganism-caused diseases are one of the greatest predicaments faced by world. The disease conditions worsened due to development microbial resistance against numerous antimicrobial agents like quinolones, vancomycin, macrolides, tetracyclines, β-lactam antibiotics, etc. There will always be a vital need discover new chemotherapeutic avert emergence and ideally shorten duration therapy...

Staphylococcus aureus gyrA and gyrB genes, which encode the DNA gyrase A and B proteins, have been isolated and found to map contiguously. DNA sequence analysis revealed close homology between the S. aureus gyrase subunits and their counterparts in Bacillus subtilis and Escherichia coli, including several conserved amino acid residues whose substitution in E. coli confers resistance to 4-quinol...

As in other Gram-negative bacteria, mechanisms of resistance to quinolones in Salmonella include target gene mutations, active efflux, and decreased outer membrane permeability. However, the exact contribution of these individual mechanisms to resistance, which may nevertheless interplay to reach high-level resistance, has not yet clearly been defined as in other bacteria such as Escherichia co...

Mechanisms of Staphylococcus aureus resistance to fluoroquinolones were characterized. Subunit A and B proteins of DNA gyrase were partially purified from fluoroquinolone-susceptible strain SA113 and resistant isolate MS16405, which was 250- to 1,000-fold less susceptible to fluoroquinolones such as ciprofloxacin, norfloxacin, ofloxacin, temafloxacin, and sparfloxacin than SA113 was. The superc...

The accumulation of bacterial antibiotic resistance is a dramatic demonstration of Darwin's dictum of the survival of the fittest, with serious practical consequences for the treatment of infection. Patterns and mechanisms of resistance undergo continuous evolution and, while the prevalence of methicillin-resistant Staphylococcus aureus has stabilized in the UK, other resistances are proliferat...

Two patients (patients A and B) infected with Salmonella typhimurium failed ciprofloxacin therapy, and the posttherapy isolates had reduced susceptibilities to quinolones; 6 of 11 isolates from patient B were also cross-resistant to chemically unrelated agents. No transferable resistance, chloramphenicol-acetylating enzymes, or beta-lactamases were detected. For 13 of 14 isolates, the concentra...

Abstract Antimicrobial resistance (AMR) is one of the top ten global public health threats facing humanity by menacing effective use available antimicrobials for treatment an ever-increasing range infections caused bacteria. Its potential recognize transmission to humans contact with commensal and zoonotic resistant bacteria from animal food sources. The aim this study describe multi-drug (MDR)...

DNA gyrase is a target of quinolone antibacterial agents, but the molecular details of the quinolone-gyrase interaction are not clear. Quinolone resistance mutations frequently occur at residues Ser(83) and Asp(87) of the gyrase A subunit, suggesting that these residues are involved in drug binding. Single and double alanine substitutions were created at these positions (Ala(83), Ala(87), and A...