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.

PROGNOSTIC PARAMETERS OF THE SUSCEPTIBILITY OF STAPHYLOCOCCUS SPP. TO AMINOGLYCOSIDES AND DOXYCYCLINE.

OBJECTIVE: The aim: To perform microbiological investigation and analytic mathematic prediction of clinical isolates of S. aureus to aminoglycosides in patients with severe burns. PATIENTS AND METHODS: Materials and methods: We analyzed resistance of 199 S. aureus strains to aminoglycosides (gentamicin, tobramycin and amikacin) and doxycycline from 435 patients treated in the regional hospital due to burns for the period from 2011-2017. RESULTS: Results: We created predictive curves for the prediction of susceptibility of S. aureus strains to aminoglycosides and doxycycline based on the changes in S. aureus resistance during the years of observation and expressed in mathematic equations. Susceptibility of S. aureus to gentamicin was 42.86 % at the end of observation and will decline in future. Despite tobramycin was efficient against 72.86 % of strains in 2017, mathematic modeling indicates rapid decline in its efficacy in future. Efficacy of amikacin was dropping during the last years, but according to the equation it efficacy will increase over 60 % in 2018. S. aureus susceptibility to doxycycline was 65.38 % in 2017 and mathematic modeling indicates its gradual decline in the nearest future. CONCLUSION: Conclusions: Predicitive values of S. aureus susceptibility indicates not sufficient efficacy of these drugs in patients with infectious complications of burns. Tendency of the slight decline of S. aureus susceptibility to doxycycline still indicates sufficient levels of its efficacy in the nearest future. This justify its use as a second-line therapy with the causative agent in patients with burns.

The research of antimicrobial efficacy of antiseptics decamethoxin, miramistin and their effect on nuclear DNA fragmentation and epithelial cell cycle.

OBJECTIVE: Introduction: Nowadays, the study of biological safety of modern cationic surface-active antiseptics with a wide antimicrobial spectrum has acquired particular importance. The aim was to study antimicrobial effectiveness of antiseptics decamethoxin, miramistin and their influence on nuclear DNA fragmentation and cellular cycle. PATIENTS AND METHODS: Materials and methods: A comparative microbiological study of antimicrobial efficacy and a cytometric study of the effect of decamethoxin 0,02% and miramistin 0,01% on the cellular cycle were carried out. Antimicrobial activity of decamethoxin and miramistin was estimated by their minimal inhibitory and minimal microbicidal concentrations against opportunistic microorganisms using serial double dilution technique. Decamethoxin and miramistin cytotoxicity on anterior corneal epithelial cells, after their two-week daily instillation into the eyes of a Vistar line male rats was studied using flow cytometry. The parameters of epithelial cellular cycle, nuclear DNA fragmentation and apoptosis under the influence of antiseptics were registered. RESULTS: Results: High antimicrobial effect of decamethoxin and miramistin against Gram-positive, Gram-negative bacteria with the significant advantages of decamethoxin were found (р<0,001). Decamethoxin caused minimal influence on anterior corneal epithelial cells, the insignificant decrease of their proliferation index, low increase of apoptosis (0.68%), no difference of mitotic activity (p>0.05). But the use of miramistin resulted in the significant increase of nuclear DNA fragmentation, decrease of proliferative activity (р<0.05). CONCLUSION: Conclusions: Higher antimicrobial effect against a wide range of opportunistic pathogens is proved in decamethoxin 0,02% comparably to miramistin 0,01% (р<0,001). In prolonged antiseptic use of the first one there were found no cytotoxic and no pro-apoptotic effects on the epithelium (р<0,05).

The analytical prognosis of the susceptibility to aminoglycosides and doxycycline inacinetobacter baumanniiisoolated from burns of intensive care unit patients.

OBJECTIVE: Introduction: Clinical strains of A.baumannii are becoming highly important in hospital-acquired infections, especially because of their association with low susceptibility to antibiotics, which requires in-depth study with a prognostic determination of the dynamics of antimicrobial efficacy of antibiotics. The aim was to investigate of prognostic models of aminoglycoside antibiotics effectiveness on the basis of the mathematical analysis of real susceptibility of A.baumannii clinical strains, isolated from patients in BICU. PATIENTS AND METHODS: Materials and methods: In the research there were enrolled 435 patients who had undergone treatment of the 2ndb - 3rd degree burns at the burn department of the Vinnitsa Regional Clinical Hospital N. I. Pirogov during 2011-2016. In total, 222 clinical strains of A.baumannii were isolated in early period after burn trauma before antibiotic therapy. The susceptibility of clinical strains A.baumannii to the gentamicin, tobramycin, amikacin, doxycycline was defined by qualitative disco-diffusion and quantitative double dilution methods. RESULTS: Results: The results of the study demonstrated a low susceptibility of clinical strains of A.baumannii to the studied aminoglicosides and doxycycline. During 2011-2016 the highest sensitivity of Acinetobacter to gentamicin (65%), tobramycin (68,63%) was estimated in 2015. But determined in 2016-2017 following tendency of susceptibility criteria of Acinetobactergave the possibility to found prognostic decreasing of gentamicin and tobramycin efficacy against this pathogen (less than 50%) in critically ill with burns. CONCLUSION: Conclusion: A.baumannii, pathogens of infectious complications in patiens, were characterized by a decrease in sensitivity to gentamycin, tobramycin and amikacin. Despite of low efficacy rate of doxycycline the recovery of its effectiveness against A.baumannii is excepted.

Characteristics of infectious complications in critically ill patients.

OBJECTIVE: Introduction: Patients, undergoing treatment in the intensive care units (ICU) often (51&) suffer from the infections and predominantly (71&) receive antibiotics. The aim: We aimed to review scientific literature, that highlights recent developments in etiology and emerge problems of struggling infectious complications in critically ill. PATIENTS AND METHODS: Materials and methods: We performed a search of literature from 1994 to 2018 years in Google Scholar, PubMed, MedLine, Embase, Cochrane. Data from 70 articles devoted and books to the problem were accumulated and synthesized in the article. CONCLUSION: Conclusion: Antibiotic resistance is considered as challenging problem in medicine throughout the world. Strains of S.aureus with antibiotic resistance have acquired genes of resistance to methicillin, vancomycin. There was registered high occurrence of E. coli, K. pneumonia, Acinetobacter spp. and P. aeruginosa, which produce extended spectrum ß-lactamases, carbapenemases and have a rising levels of resistance to aminoglycosides and fluoroquinolones.