A broad-spectrum antimicrobial agent, a derivative of fluoroquinolone, suppresses bacterial DNA-gyrase (topoisomerases II and IV, responsible for the process of supercoiling the chromosomal DNA around the nuclear RNA, which is necessary for reading out genetic information), disrupts DNA synthesis, growth and division of bacteria; causes significant morphological changes (including the cell wall and membranes) and the rapid death of the bacterial cell.It acts bactericidal on gram-negative organisms during rest and division (since it affects not only DNA-gyrase, but also causes lysis of the cell wall), Gram-positive microorganisms are effective only during the fission period. Low toxicity for macroorganism cells is explained by the absence of DNA-gyrase in them. Against the background of taking ciprofloxacin, there is no parallel development of resistance to other antibiotics that do not belong to the group of DNA-gyrase inhibitors, which makes it highly effective against bacteria that are resistant, for example, to aminoglycosides, penicillins, cephalosporins, tetracyclines and many other antibiotics. Gram-negative aerobic bacteria are sensitive to ciprofloxacin: enterobacteria (Escherichia coli, Salmonella spp., Shigella spp., Citrobacter spp., Klebsiella spp., Enterobacter spp., Proteus mirabilis, Proteus vulgaris, Serratia marcescens,
Hafnia alvei, Edwardsiella tarda, Providencia spp., Morganella morganii, Vibrio spp., Yersinia spp.), other gram-negative bacteria {Haemophilus spp., Pseudomonas aeruginosa, Moraxella catarrhalis, Aeromonas spp., Pasteurella multocida, Plesiomonas shigelloides, Campylobacter jejuni, Neisseria spp.), some intracellular pathogens - Legionella pneumophila, Brucella spp., Chlamydia trachomatis, Listeria monocytogenes, Mycobacterium tuberculosis, Mycobacterium kansasii, Corynebacterium diphtheriae; Gram-positive aerobic bacteria: Staphylococcus spp. {Staphylococcus aureus, Staphylococcus haemolyticus, Staphylococcus hominis, Staphylococcus saprophyticus), Streptococcus spp. {Streptococcus pyogenes, Streptococcus agalactiae).
The majority of staphylococci, resistant to methicillin, are resistant to ciprofloxacin. Sensitivity Streptococcus pneumoniae, Enterococcus faecalis, Mycobacterium avium (located intracellularly) - moderate (to suppress them, high concentrations are required).
To the drug are resistant: Bacteroides fragilis, Pseudomonas cepacia, Pseudomonas maltophilia, Ureaplasma urealyticum, Clostridium difficile, Nocardia asteroides. He is effective against Treponema pallidum.
Resistance develops very slowly, because on the one hand, after the action of ciprofloxacin are left with persistent microorganisms, and on the other - the bacterial cells do not have the enzymes that inactivate it.