HOW DOES QUINOLONES ANTIBOTIC RESISTANCE DEVELOP?

Document Type : Original Article

Authors

1 Department of Medical Microbiology and Immunology, Faculty of Medicine, Assiut University, Assiut, Egypt & Ministry of Health and Population, Assiut, Egypt

2 Department of Medical Microbiology and Immunology, Faculty of Medicine, Assiut University, Assiut, Egypt

3 Department of Clinical and Chemical pathology, Faculty of Medicine, Cairo University, Cairo, Egypt

Abstract

The quinolone antibiotics arose in the early 1960s, with the first example having a narrow spectrum of activity with unfavourable pharmacokinetics. Over time, the development of new quinolone antibiotics has led to improved equivalents with an expanded spectrum and high efficacy. Nowadays, quinolones are broad-spectrum antibiotics that are active against both Gram-positive and Gram-negative bacteria, as well as mycobacteria, and anaerobes. They exert their actions by inhibiting bacterial nucleic acid synthesis through disrupting the enzymes topoisomerase IV and DNA gyrase, and by causing damage of bacterial chromosomes. Acquired bacterial resistance to quinolones rises due to the abuse of these drugs. Mechanisms contributing to quinolone resistance are mediated by chromosomal mutations and/or plasmid gene uptake that modify topoisomerase targets, modify the quinolone, and/or reduce drug accumulation by either decreased uptake or increased efflux. This review describes the history of development of this class of antibiotics, different generations, mechanism of action, along with the resistance mechanisms which reduce the quinolones' activities against different microorganisms.