The ability of bacteria to produce a biofilm is considered an important virulent property in pathogenesis of mastitis. The purpose of studies is to investigate the ability to form biofilms, their density, to determine and compare the sensitivity to antibacterial drugs of planktonic and biofilm forms of the main bovine mastitis pathogens on dairy farms of the Western region of Ukraine.Diagnosis of bovine mastitis, selection of milk samples and secretions of the mammary gland, microbiological studies were carried out in accordance with generally accepted methods. The performed studies have established that among pathogens, both acute and chronic forms of mastitis, the most productive film-forming ability had S. aureus strains, which on average 1.5 times more often formed the biofilm than Str. agalactiae and Str. dysgalactiae strains. It was revealed that S. aureus strains, isolated from cows under the subclinical form of mastitis and at carriage, 2.0 times (p <0.05) more often formed biofilms than in the clinical form of mastitis. The highest sensitivity of planktonic bacteria to pathogens of mastitis of streptococci and staphylococci was to ceftriaxone and doxycycline (100-80.9%). The least susceptible streptococci and staphylococci were to benzylpenicillin 32.3-45.4%, and the susceptibility of S. aureus strains was 19.0%.When determining the influence of antibiotics on biofilm forms of bacteria found that cells in the biofilm are more resistant to antibacterial drugs. It was found that antibiotic enrofloxacin completely inactivated streptococci and staphylococci in biofilms. Also, antibiotics ceftriaxone and doxycycline were also effective on bacteria in biofilms. At the same time, under the action of antibiotics penicillins, aminoglycosides and macrolides, the amount of microbial cells that survived in a biofilm was about lg 5.3 CFU/cm2 of area. Consequently, studies have shown that it is necessary to seek effective methods and develop new drugs that would influence the bacteria in biofilms to effectively treat bovine mastitis.
The article presents data on serological studies of 573 sera samples of cattle that were collected from the farms affected by leptospirosis in different regions of Ukraine in the period of 2014–2015. Samples were investigated by the microscopic agglutination test (MAT), which was conducted within eight serological groups of Leptospira and nine serovars: Sejroe (serovars polonica and hardjo), Hebdomadis (serovar kabura), Tarassovi (serovar tarassovi), Pomona (serovar pomona), Grippotyphosa (serovar grippotyphosa), Canicola (serovar canicola), Icterohaemorrhagiae (serovar copenhageni), and Australis (serovar bratislava). The circulation of L. interrogans serovar hardjo among cattle has been observed in all 11 regions of Ukraine investigated within 25.8–60.0% of the leptospirosis-positive serum samples in these regions.Antibodies in the cattle sera against serovar hardjo (serogroup Sejroe) were detected in 139 of the 370 cows reacting positively in MAT. Overall, they were detected in 24.3% animals out of the total of 573 cows investigated. These are the preliminary results, however, in our opinion, they should allow to include the serovar hardjo in a standard panel of strains for MAT in Ukraine.
Contamination of food with nitrates is a generally recognized problem. Milk is the basis for the production of many milk mixtures for baby food, and children are considered to be the most vulnerable category to the harmful influence of nitrates. The purpose of the search was to investigate the denitrification of milk with different amounts of nitrates by the denitrifying microorganisms of Staphylococcus carnosus in the technology of production of sour-milk products. The denitrification process of S. carnosus milk in the amount of 103 CFU.cm-3 was found to reduce the nitrate content by an average of 88.0 ±3.9 mg.kg-1 and in the samples of the first group was 10.3 ±2.4 mg.kg-1, the second 110.7 ±4.1 and the third 214.5 ±6.3 mg.kg-1, respectively. In the search of the denitrification process of S. carnosus milk in the amount of 104 CFU.cm-3, was found that in the ready yogurt in the samples of the first group the amount of nitrates was 1.1 ±0.1 mg.kg-1, in the second group 56.4 ±3.5 mg.kg-1, and in the third 159.5 ±4.1 mg.kg-1 respectively. In the search of the denitrification process of S. carnosus milk in the amount of 105 CFU.cm-3, was found that nitrates were practically absent in the samples of the first group, the second group did not exceed 10 mg.kg-1, and the third was 107.4 ±3.9 mg.kg-1. Therefore, received data indicate the possibility of using strain S. carnosus No. 5304 for denitrification of milk with a high content of nitrates in the technology of production of fermented milk products, in particular yogurt.
Державний науково-дослідний інститут з лабораторної діагностики та ветеринарно-санітарної експертизи; 2 Тернопільській національний технічний університет імені Івана Пулюя; 3 Державний науково-контрольний інститут біотехнології та штамів мікроорганізмів ВИВЧЕННЯ ЗДАТНОСТІ ДО ФОРМУВАННЯ БІОПЛІВОК ПОЛЬОВИМИ ІЗОЛЯТАМИ S. АUREUS, ВИДІЛЕНИМИ ІЗ СИРОВИНИ І ПРОДУКЦІЇ ТВАРИННОГО ПОХОДЖЕННЯ Формування біоплівок Staphylococcus аureus є актуальною проблемою, оскільки цей процес пов'язаний з регуляцією експресії генів, які мають особливість впливати на функції інших генів. Позаклітинний матрикс біоплівок містить компоненти, що унеможливлюють проникнення нейтрофілів крові для знешкодження збудника у глибоких шарах біоплівок, що спричиняє рецидиви стафілококової інфекції, навіть, після антибіотикотерапії. Стаття містить результати досліджень з виявлення інтенсивності біоплівкоутворення польовими ізолятами Staphylococcus аureus, виділеними із зразків сировини та продукції тваринного походження.
In the course of the research, the microorganisms that often caused disease for animals were used, according to the literature, were genetically predisposed to resistance to traditional antibiotics and needed to find new effective means to combat them. It was used different antibiotic substances benzalkonium chloride, silver nanoparticles, and promising in this direction, essential oils of plants: fir, eucalyptus. The article provides information on the selection and study of the efficacy of substances, components with essential oils necessary for the development of complex bactericidal agents and the study of their antimicrobial activity against microorganisms. In determining the antimicrobial activity of essential oils, test cultures were used: Microccoccus luteus ATCC9341, Microccoccus lisogenicus, B. subtilis AATCC6633, B.cereus ATCC6633, S. aureus 209-P, S. zooepidemicus, Clebsiella spp, Salmonella cholerae suis, Pasterella multocida from the museum of State Scientific and Control Institute of Biotechnology and strains of microorganisms. The determination of fungicidal acity was performed on microscopic molds of Penicillium citrinum, Penicillium urticae, Aspergillus flavus, Aspergillus ochraceus. In experiments with Staphilococcus aureus, Streptococcus zooepidemicus, Pasteurella multocida, the antibiotic action of essential oils of eucalyptus and puff was confirmed and the possibility of its enhancement by the addition of quaternary ammonium compounds was confirmed. According to the results, the use as an alternative to antibiotics and disinfectants of preparations based on vegetable essential oils in the form of aerosols not only improves the number of animals from respiratory infections of bacterial origin, but also significantly improves the ecological conditions of the work of personnel in livestock buildings, promotes treatment and prevention respiratory diseases. The investigations have proved the expediency of using vegetable essential oils for the design of highly effective drugs and the possibility of enhancing their antimicrobial activity by quaternary ammonium compounds and silver nanoparticles, as well as a complex preparation «Asept» for aerosol application in the presence of animals.
A comparative analysis of the use detergents disinfectants with different active ingredients: heotsyd (polihexametylenhuanidin hydrochloride, benzalkonium chloride) virosan (alkildymetylbenzylamoniya chloride, glutaraldehyde) neohlor (sodium hypochlorite) orhasept (benzalkonium chloride, lactic acid) and determination of their minimum effective concentration and exposure required for removal of E. coli and S. aureus on test sites: stainless steel, tile, concrete, brick was were conducted. At sterilized in an autoclave test objects applied to 1 cm3 culture E. coli and S. aureus at a concentration of 2 billion. mikr.til per cm3. Contaminated test objects dried and placed into cuvettes horizontally and vertically and spray disinfectants applied explored solutions, while noting their exposure concentration and amount spent. Objects whish were exposure by the same scheme, but with using sterile water were used as control. After a certain period of time by sterile cotton swab from experimental and control test objects were taken probes. Then 1 cm3 initial suspension of each of these tubes were placed in the appropriate environment for 24 hours. at thermostat at 37 °C. By the changes in defined media presence or absence of these microorganisms were determined.Stated that disinfectants orhasept and virosan in 0.1% concentration and heotsyd neohlor in 0.5% concentration completely disinfected from E. coli and S. aureus on surfaces of the test objects for 10 min, confirms their detergent disinfectant effect. Effective concentrations of disinfectants regarding test organisms consistent with regulations for their use.
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