title: Alterations in macromolecular composition and cell wall integrity by ciprofloxacin in Mycobacterium smegmatis.
abstract: The present study has been undertaken to explore the biochemical mechanism of antimycobacterial action of a potent fluoroquinolone i.e. ciprofloxacin in Mycobacterium smegmatis. Cells grown in the presence of a subinhibitory concentration (IC50) of ciprofloxacin had a significantly lower content of all the major macromolecules i.e. DNA, RNA, proteins and lipids with maximum inhibition in DNA concentration as compared to control. Significant quantitative changes were also observed in the various chemical constituents of cell wall of ciprofloxacin grown cells. A decrease in the number of binding sites for a fluorescent probe L-anilinonapthalene-8-sulphonate (ANS) in ciprofloxacin grown cells suggested structural changes on the cell surface. Significant changes were also observed in the morphology of cells grown in the presence of ciprofloxacin by scanning electron microscopy (SEM). Our results suggest that ciprofloxacin exerts its antimycobacterial activity by affecting the cell wall as well as various macromolecules, particular DNA, the vital component for cell survival and growth.
authors.affiliation: Dept. of Biochemistry, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
authors.forename: I
authors.initials: I
authors.lastname: Verma
authors.forename: A
authors.initials: A
authors.lastname: Rohilla
authors.forename: G K
authors.initials: GK
authors.lastname: Khuller
mesh_terms: D000817:Anilino Naphthalenesulfonates / Q000378:metabolism; D000890:Anti-Infective Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000032:analysis; D002473:Cell Wall / Q000737:chemistry / Q000187:drug effects; D002939:Ciprofloxacin / Q000494:pharmacology*; D004269:DNA, Bacterial / Q000032:analysis; D005456:Fluorescent Dyes / Q000378:metabolism; D008055:Lipids / Q000032:analysis; D008855:Microscopy, Electron, Scanning; D008856:Microscopy, Fluorescence; D020102:Mycobacterium smegmatis / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D012329:RNA, Bacterial / Q000032:analysis
chemical_list: D000817:Anilino Naphthalenesulfonates; D000890:Anti-Infective Agents; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D005456:Fluorescent Dyes; D008055:Lipids; D012329:RNA, Bacterial; D002939:Ciprofloxacin; C027132:1-anilino-8-naphthalenesulfonate