Keywords
Abstract
The ability of microorganisms to form film creates significant problems in clinical practice. One of the ways to solve the problem is to assess the antibiofuel effect of modern antimicrobial drugs and study their effect on different stages of biofilm formation.
The aim of the study was to establish the sensitivity of Pseudomonas aeruginosa biofilms and persister cells to the action of ciprofloxacin.
The antibiofilm activity of ciprofloxacin against the P. aeruginosa clinical isolate was investigated at concentrations of 0,5 MIC, 2,0 MIC and 5,0 MIC by sorption of gentian violet by biofilm structures, as well as using resazurin. The viability of bacteria in the formed biofilm was assessed by fluorescence microscopy
using acredine orange and propidium iodide dyes. The formation and reversion of metabolically inactive cells were studied by activating the SOS-response in bacteria.
The results obtained indicate that ciprofloxacin is capable of disrupting film formation and destroying mature P. aeruginosa biofilms. Under the action of the drug at concentration of 5,0 MIC, a decrease in the biomass (25,0–33,6 %) and number of metabolically active cells (78,6–100 %) was recorded at various
stages of biofilm formation. It was found that ciprofloxacin at a concentration of 0,5 MIC stimulates the formation of P. aeruginosa biofilm. The drug does not prevent the formation of persisters, but is able to reduce their number in the formed subpopulation. Persistent cells are sensitive to the drug.
Thus, ciprofloxacin has an antibiofilm effect against P. aeruginosa, which is more pronounced at a concentration exceeding the MIC. At a subinhibitory concentration, ciprofloxacin is able to stimulate film formation, which must be taken into account in the drug use regimens in clinical practice. There is a need
for further in-depth studies in vivo on various models of biofilm infections using strains with different sensitivity to antimicrobial drugs.