The investigation of the relationship between biofilm-forming properties of clinical strains of p.aeruginosa and their sensitivity to antiseptic medicines

Abstract

High antimicrobial properties of antiseptics determine the scientific interest in the study of their effect on the biofilm formation of clinically significant pathogens and the detection of a probable dependence between the sensitivity of bacteria to them and the ability to form biofilms. The aim — was to study the biofilm-forming properties of clinical strains of P.aeruginosa, depending on their sensitivity to various antiseptic medicines. 30 clinical strains of P.aeruginosa were isolated and identified from the patients with infectious complications of different areas who had been treated at the burn, intensive care and surgical units. The study of biofilm-forming properties of clinical isolates of P.aeruginosa was performed by using the spectrophotometric technique by G.D. Christensen (MtP microtiter plate test). The sensitivity assessment of the derived strains to antiseptics (decametoxine, decasan, miramistin, chlorhexidine) was done by double serial dilutions according to the standard procedure approved by the Order №167 of the Ministry of Public Health of Ukraine. The statistical processing of the results obtained was carried out by “Microsoft Excel 2010” software package. In order to determine the relationship between the biofilm formation and sensitivity to antiseptic medicines of P. aeruginosa strains, we determined the correlation coefficient (r-Pearson coefficient). The clinical strains of P.aeruginosa were found to be the most sensitive to decasan and miramistin, and their MICs did not differ 70,31±25,98 mg/ml and 68,5±33,20 mg/ml respectively. Chlorhexidine has been shown a reducing of antimicrobial efficiency against P.aeruginosa (MIC 115,62±59,75 μg/ml). High biofilm-forming properties of clinical isolates P.aeruginosa have been proved. The optical density of the biofilms formed by these microorganisms was 0,674±0,17 density units for 24 hours of cultivation. A direct correlation between the sensitivity of strains P.aeruginosa to decamethoxine, decasan, miramistin and their biofilm-forming properties was established. The sensitivity of the clinical strains to chlorhexidine did not depend on their biofilm potential. Clinical strains of P.aeruginosa have high biofilm-forming properties and retain sensitivity to antiseptic medicines based on cationic surfactant antiseptics. Decamethoxine and miramistin provide the highest antimicrobial action on P.aeruginosa isolates. The sensitivity of P.aeruginosa to decamethoxine, decasan, miramistin has shown to be in a direct correlation with their biofilm-forming properties.