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. In the structure of the corneal microbial diseases bacterial keratitis take second rate position after viral keratitis. They are characterized by a severe course and often leads to complications that require surgical treatment. P. aeruginosa is the main causative agent of keratitis associated with the contact lenses wearing. The aim of our work was to check up the combined action of fluoroquinolones, tobramycin and antiseptic decamethoxine on clinical strains of P. aeruginosa in vitro with microbiological methods. The studies were performed on clinical strains of P. aeruginosa, which were sensitive as well as resistant to the studied antimicrobial compounds. Statistical analysis of the results was performed using standard software packages “STATISTICA +” and “Microsoft Excel 2010”. Calculated the arithmetic mean (Xcr), standard deviation (σ). The results of our investigation demonstrated 2–4 times antimicrobial susceptibility increasing for quinolone and tobramycin resistant clinical strains of Pseudomonas aeruginosa in the presence of subinhibitory concentrations of decamethoxine. Oftaquix, floximed and tobrex eye drops contain enough amount of antibiotics that is capable to affect both sensitive and resistant strains of P. aeruginosa in vitro. The revealed synergetic antipseudomonal action gives us grounds for further research of the combination etiotropic therapy effect on the course of the experimental keratitis caused by P. aeruginosa.
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.
It is known that bacteria colonize endotracheal intubation tubes [EIT], form biofilms. Bacterial cells that are in the film matrix are protected from the effects of external factors and differ in high levels of resistance to the action of antibiotics, antiseptics, and disinfectants. The purpose of our study was to determine the sensitivity of the antiseptics of biofilm and planktont forms of non-fermentable gram-negative bacteria to the action of the antiseptics of decamethoxin, chlorohexidine bigluconate, povidone iodine, hydrogen peroxide. In order to create bacterial biofilms, sterile fragments of the endotracheal tubes were placed in test tubes with meat-peptone broth and the daily culture of the studied strain of microorganisms was blocked. To determine the influence of antiseptics on biofilms of bacteria, the method of two successive dilutions was used. The results of a comparative study of the activity of antiseptic agents (decamethoxin, bichluconate chlorhexidine, povidone iodine, hydrogen peroxide) in relation to planktonic and biofilm forms of pseudomonad and acinetobacter strains testify that in all investigated antiseptics and bacterial films pseudomonads forms are more resistant to drags preparations than in planktonic form. In bichluconate, chlorhexidine and decamethoxin MBcK for a bacterial film are 3,2 times greater than for a planktonic form. The smallest difference MBtsK for planktonic and biofilm forms of pseudomonad was in the drug povidone-iodine. MBcC bichluconate chlorhexidine for the biofilm form of acinetobacter, in comparison with planktonic form, was 3,3 times higher, for decamethoxin in 3.7 times, for povidone-iodine in 3,5 times. Biopharmaceutical forms of gram-negative nonfermenting bacteria have the ability to achieve high levels of resistance to antiseptics.
Annotation. The use of artificial lung ventilation in patients of intensive care unit often leads to airway contamination of conditionally pathogenic microorganisms and the development of ventilator-associated pneumonia. The clinical manifestations of ventilator-associated pneumonia can vary widely from mild to development of critical conditions accompanied by septic shock. This significantly worsens the patient's condition and prognosis for effective treatment. The paper presents the results of the study of the use of adhesive antiseptic compositions based on the domestic antiseptic drug decamethoxin in order to give antimicrobial properties to intubation tubes. An antibacterial adhesive was applied to the surface of segments of the endotracheal intubation tube, after which the samples were dried in a sterile box. The sensitivity of the microorganisms to the components of the antiseptic compositions was studied by the diameter of the growth retardation zone around the studied fragments of endotracheal intubation tubes placed in the thickness of the pre-seeded microorganism’s dense nutrient medium. The results were statistically analyzed using standard application package for biomedical research “STATISTICA 5.5”. It has been proved that adhesive film-forming compositions based on decamethoxin confer pronounced antimicrobial properties to endotracheal intubation tubes. The most susceptible to antimicrobial activity were gram-positive microorganisms of the genus Staphylococcus, and the most resistant were representatives of gram-negative bacteria of the genus Acinetobacter. The obtained research results allow us to predict the effectiveness of the use of adhesive hydrophilic and hydrophobic antiseptic compositions based on the domestic antiseptic decamethoxin to provide protective properties of the surface of endotracheal tubes, prevent the process of bacterial film formation and prevention of ventilator-associated patients.
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