Research of the activity of local anesthetics and antiseptics regarding clinical isolates of Acinetobacter baumannii as pathogens of postoperative infectious complications.

BACKGROUND: About 60% of all nosocomial infections are caused by microorganisms found in biofilms. Acinetobacter baumannii, as a pathogen of nosocomial infections, occur more frequently in surgical hospitals. The aim of the study was to study the in vitro formation of A. baumannii monotype biofilms under the influence of local anesthetics and antiseptics Materials and methods. The antimicrobial activity of local anesthetics (0.25-0.5%, bupivacaine, 2.0% lidocaine, 0.75% ropivacaine) and antiseptics (decamethoxine 0.1%, octenidine 0.1%, chlorhexidine 0.05%) ) against clinical strains of A. baumannii and studied their ability to produce biofilms. RESULTS: The bacteriostatic effect of local anesthetics on A. baumannii within the current concentrations of these drugs, which provide analgesic effect, has been proven. The given results indicate that A.baumanni cultures have a pronounced ability to form biofilms. Clinical strains of opportunistic microorganisms A. baumannii circulating in the hospital environment are highly sensitive to antiseptics decamethoxine and octenidine, chlorhexidine has a weak bactericidal effect against acinetobacteria. The results of studying the effect of local anesthetics on the process of formation of the strain "young" biofilms showed the presence of a dose-dependent effect. The greatest inhibitory activity against "young" biofilms was detected under the combined action of the antiseptic decamethoxine (in concentrations, not exceeding 3.9 µg / ml) and anesthetics (OD-0,199-0,223) (p <0,05). CONCLUSIONS: Scientific research on various aspects of the formation (or destruction) of bacterial biofilms is a relevant and promising area that will change approaches to the prophylaxis and treatment of a number of infections, including postoperative infectious complications.

BIOFILM FORMING ACTIVITY OF NON-FERMENTING GRAM-NEGATIVE BACTERIA.

OBJECTIVE: The aim: To study the influence of chemical, physical factors on the biofilm forming activity of P. aeruginosa, A. baumannii. PATIENTS AND METHODS: Materials and methods: Biofilm forming activity of P. aeruginosa (10 isolates) and A. baumannii (10 isolates) was studied in nutrient media of different composition. There was used the method in 96-well crystalline violet staining plates with spectrophotometry (STAT FAX®4300, wavelength of 620 nm). RESULTS: Results: Results showed that in standard medium (trypto-soy broth), strains of P. aeruginosa (90%) and A. baumannii (60%) obtained high biofilm forming activity. A. baumannii formed biofilms even in sterile water. Biofilm forming activity of urease positive P. aeruginosa increased in the medium with 1.0% urea. Both Acinetbacteria and Pseudomonas intensively produced their biofilms in the presence of 5% serum or sub-bacteriostatic concentrations of levofloxacin in the media. High concentrations of sodium chloride inhibited their biofilm activity. CONCLUSION: Conclusions: Isolates of Acinetobacter and Pseudomonas obtain the protective biofilm-forming ability under such adverse environmental conditions as insufficient nutrients, high osmotic pressure, the presence of antibiotics but at high concentrations sodium chloride biofilm-formation is stimulated only in the first bacteria and suppressed in the second one.