The aim: To study the influence of chemical, physical factors on the biofilm forming activity of P. aeruginosa, A. baumannii. 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 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. 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.

Annotation. The problem of treatment of burn wounds is closely related to the specificity of the spectrum of microorganisms that impair wound healing in this category of patients. A generally alarming trend in recent years is the significant increase in the etiological structure of wound infection, both in frequency and in severity and in the difficult choice of treatment tactics in the isolation of poly antimicrobial resistant strains of Pseudomonas aeruginosa, Acinetobacter baumannii. The aim of our study was to create a model of biofilm formed by bacteria on the wound surface and to investigate, in a comparative study, the sensitivity of planktonic and film forms of non-enzymatic gram-negative bacteria to a composition based on decamethoxin with prolonged antiseptic action. To determine the effect of the antiseptic composition on planktonic and film forms of bacteria there was used the method of two consecutive dilutions. The results of a comparative study of the activity of the antiseptic composition with decamethoxin planktonic and biofilm forms of strains of NFGB indicated that in the bacterial film bacteria were more resistant to drugs than in planktonic form. Film forms of A. baumannii and B. cepacia have a sensitivity to decamethoxin at a concentration of 13.6±1.95 µg/ml and 15.6±0 µg/ml, respectively. P. aeruginosa film forms have a higher degree of resistance to the test composition with decamethoxin (MBc 137.5±30.6 μg/ml). Disinfection of the planktonic form of NFGB is 10 times faster than the film form, the destruction of which is achieved with prolonged exposure of 120–150 minutes.

The problem of the antibiotic resistance development of pathogenic microorganisms to the main groups of antibacterial drugs has evolved from medical to socio-economic. There is a resistance increase of P.aeruginosa, A.baumannii belonging to the group of gram-negative non-fermenting bacteria (GNB), to antibiotics that are used in medicine. The possibility of acquiring GNB resistance to the main groups of antibacterial drugs is related to the ability of bacteria to acquire new genetic information. The production of metal-beta-lactamase by GNB become a widespread problem of resistance to beta-lactam antibiotics. Detection of resistance genes to beta-lactam antibiotics blaVIM, blaOXA 23, blaOXA 40, blaOXA 69 and blaOXA 100 was performed using real time polymerase chain reaction (PCR-RT). Sensitivity of isolated strains of microorganisms to antibiotics was investigated using the standard disco-diffusion method (DDM). Influence of meropenem on formation of microorganism resistance was investigated in vitro by method of microorganisms passage on meat-peptone broth (MPB) with increasing concentrations of antibiotics. In the process of research, 14 clinical strains of P. aeruginosa and 30 strains of A.baumannii were isolated and identified, almost all strains of these types of bacteria, characterized by resistance to antibiotics-carbapenems and third and fourth generation of cephalosporins. At the same time, the three strain-carries of markers of beta-lactamase products exhibited resistance to carbapenems, and one of the strains (P.aeruginosa No. 68) was capable of producing MBL, according to DDM, was sensitive to carbapenems and MCC was 31.2 μg / ml for it. Among the investigated strains of A.baumannii 18 (60%) out of 30 isolated ones were potential producers of beta-lactamases, capable of inactivating carbapenem antibiotics. In this case, only 6 out of 18 strains showed resistance to carbapenems according to DDM. Sensitivity to carbapenems revealed all strains of the beta-lactamase producers OXA 69 and OXA 100 and three strains – OXA 23. In this work, modern ideas about the mechanisms of development of resistance of GNB were described, isolated from patients of medical institutions (Vinnytsa city), the most common are producers of beta-lactamase types of OXA 23, OXA 69, OXA 100 and VIM.

Annotation. P. aeruginosa, A. baumannii are the causative agents of severe wound infections, ventilator-associated pneumonia, catheter-associated septic conditions and other severe pathological processes. The ability of bacteria to form biofilms in affected tissues plays an important role in the pathogenesis of these diseases. Therefore, the purpose of our work is to study the influence of certain external factors on the ability of bacteria to form biofilms. The ability of bacteria to form biofilms in affected tissues plays an important role in the pathogenesis of these diseases. 5 clinical strains of P. aeruginosa and 5 strains of A. baumannii were used in this research. The ability to form biofilms was studied in 96-well polystyrene plates by the spectrophotometric method, which is based on the ability of the crystal violet dye to bind to the cells and matrix of the biofilm. Statistical processing of the obtained results was carried out using Excel Microsoft Office tables. The effect of the presence of certain sugars and nitrogen-containing compounds in the cultivation medium on the processes of biofilm formation by pseudomonads and acinetobacteria was investigated. As a result of the research, it was established that acinetobacteria show the ability to form films, unlike pseudomonads, under the condition of their cultivation in sterile distilled water. The introduction of certain carbohydrates or urea into the cultivation medium intensified the biofilm-forming properties of pseudomonads to a much greater extent, compared to acinetobacteria. According to the research results, it was established that the most active process of biofilm formation occurs in both types of non-fermenting Gram-negative bacteria when there are animal blood serum proteins in the culture medium. The formation of biofilms is one of the main strategies that increases the survival of bacteria in the environment, as well as in the human body. The ability of bacteria to form biofilms is, among other things, a factor in the pathogenicity and virulence of bacteria. So, in recent years, special attention has been paid to the ability of microorganisms to form biofilms, and to the study of factors affecting this process.

The presence of the endotracheal intubation tube (EIT) in the respiratory tract is a factor contributing to the development of the VAP. The formation of biofilms on the surface of the ЕІТ is a significant factor in the pathogenesis of ventilator-associated infections of the lower respiratory tract. The purpose was to study the biological properties of the microflora of the endotracheal tubes of newborns, determining the sensitivity of planktonic and film forms of microorganisms to antibiotics. 18 intubation tubes were examined. Gram-negative bacteria (77%) were the leaders among contaminants. From tubes of newborns there were isolated K.pneumoniae isolated (36%), E.сloacae (23%). The surface of the intubation in 9% of cases tubes was colonized Pseudomonas and Stenotrophomonas, were insensitive to carbapenems, rifampicin, cephalosporins III and IV generations. P. aeruginosa has not shown sensitivity to cefoperazone/sulbactam, fluoroquinolones. There were sensitive 100% of strains P.aeruginosa to polymyxin. Stanotrophomonas were sensitive to fluoroquinolones in 100% of cases. Sensitivity of the K.pneumoniae to carbapenems and cefoperazone/sulbactam was determined in 50–58% of strains. E.cloacae strains demonstrated sensitivity to carbapenems in 100% of cases, and sensitivity to protected cephalosporins was 83%. Cefepim, meropenem, amikacin do not completely eliminate the viable cells of Stenotrophomonas, Klebsiella and Enterobacter cells from the biofilms, even under the maintenance of such a concentration during 4 days. Only viable cells of Pseudomonas in biofilms that were present in the solution of amikacin for more than a twenty-four hours were not detected. The low level of sensitivity of microorganisms colonizing endotracheal tubes to the majority of modern antibiotics and the complexity of exposure to biofilm forms of bacteria lead to complex large-scale studies and the introduction, based on their results, of protocols for treatment and prevention of infections.