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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.

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The aim of the research was to study the features of formation of dairy equipment microflora, the ability of microorganisms to form biofilms on the noncorrosive steel surface with the different roughness and to determine the effectiveness of disinfectants. It was established, that bacteria of Bacillus, Lactobacillus genera of Enterobacteriaceae family are most often extracted from the dairy equipment after the sanitary processing by modern disinfectors, in less number of cases – staphylococci, enterococci, streptococci and pseudomonades. Extracted bacteria form mainly biofilms of the high and middle density. In 100 % of cases biofilms of the high density were formed by Bacillus spp. and Enterococcus faecalis bacteria. It indicates the fact that at the disinfection of the dairy equipment, only stable bacteria that have the ability to produce a biofilm of the high density, remain on its surface. It was established, that the dairy equipment surface relief, namely roughness, has an influence on the process of biofilm formation in Escherichia coli. On the noncorrosive steel surface with the roughness 0,16±0,065 mcm Escherichia coli form biofilms of the lower density comparing with the surface with the density 0,63–0,072 mcm during 24 hours at the temperature 17 °С. It was established, that working solutions of disinfectants P3-ansep CIP, Eco chlor, Medicarine and Maxidez were more effective as to plankton bacteria. Microorganisms, formed in biofilms, turned out stable to these disinfectants. Most effective disinfectant for the influence on bacteria on biofilms is Р3-oxonia active – 150. So, the obtained data indicate that for the effective sanitary processing of the dairy equipment it is necessary to use disinfectants that influence bacteria in biofilms.

Staphylococcus aureus is one of the most important microorganism in the process of raw milk production and has significance for people’s health as it causes dangerous microbial contamination of dairy production. Furthermore, raw milk and the environment of livestock farms may be potential vehicles for distribution of antibiotic-resistant strains of S. aureus. The aim of the present study was to establish antibiotic sensitivity profiles of S. aureus depending on its origin from dairy farms, with a special focus on methicillin-resistant isolates. A total of 165 samples were collected for investigation in the period 2014–2016 from 5 dairy farms in Ukraine. All samples were analyzed for the presence of S. aureus using the Baird Parker Agar with Egg Yolk Tellurite Emulsion. Typical staphylococcal colonies were examined morphologically and for presence of coagulase and hemolysin activities. From these, positive samples for S. aureus were 62 (37.6%): 4 (6.5%) raw milk, 17 (77.4%) swabs of udder skin, 18 (29.0%) milk from cows with subclinical mastitis and 21 (33.9%) environmental samples. The standard disk diffusion method was used to determine sensitivity of S. aureus isolates to 10 antibiotics. The antimicrobial sensitivity profiles of S. aureus isolates showed differences between them, which depends on the origin of the isolates. Our results demonstrated that most of S. aureus isolates were resistant to penicillin, oxacillin and vancomycin. Of the 62 S.aureus isolates, 20 (32.3%) and 5 (8.1%) were found to be multiresistant to 3 different antibiotics, 6 (9.8%) isolates to 4 antibiotics, 12 (19.4%) and 3 (4.8%) to 5 antibiotics (P10, OX1, VA5, L10, TE30 and P10, OX1, VA5, CIP10, TE30 respectively). All isolates resistant to penicillin and oxacillin were typed by mec A gene in PCR with two primers (MecA147-F and MecA147-R). The results show that 66.7% of these isolates yielded a mecA product. The information obtained from this study is useful for understanding the prevalence of S. aureus and its antibiotic sensitivity in dairy farms and can be useful for local and national monitoring or for designing specific control programs of methicillin- and multiresistance isolates present in the food chain of milk production.

Meat and meat products are a major part of a person's ration. However, due to their high nutritional value, they are a favorable environment for the development of microorganisms and require refrigerated storage. The purpose of this work was to evaluate the storage methods for refrigerated and frozen beef by microbiological and chemical parameters and to suggest criteria for evaluating beef by the content of psychrotrophic microorganisms. It was found out that the storage of beef meat with an initial mesophilic bacterial content of about 4.88 log CFU.cm-2 of surface and psychrotrophic bacteria 3.79 log CFU.cm-2 at temperature 0 °C is only possible for 8 days, further, the microbiological indices exceed the acceptable standards. Investigation of the dynamics of microflora reproduction during the storage of beef in the frozen state at temperature -2 to -3 °C for 20 days established a decrease in 1.3 times the number of mesophilic bacteria in 10 days of storage. At the same time, the number of psychrotrophic microorganisms during this storage time was increased in 4.5 times, and 20 days in 7.9 times and amounted to 5.3 log CFU.cm-2 of surface area. This indicates that the storage of meat in the frozen state inhibits or completely stops the development of mesophilic microorganisms for 20 days. It was found out that storing of beef in the cooled state at a temperature of 0 ±0.5 °C for more than eight days is impractical, as its biochemical indices are worsening and signs of spoilage are appearing. At the same time, storing of beef in the frozen state at a temperature of -2 to -3 °C for 20 days does not cause such significant biochemical changes as in beef stored in the cooled state at a temperature of 0 ±0.5 °C for 16 days. Therefore, we have experimentally substantiated the quantitative indicators of the content of psychrotrophic microorganisms on the surface of beef intended for storage in a cooled or frozen state. The proposed microbiological criteria will improve the safety of beef.

The microorganisms that are formed in biofilm cause about 60% of chronic and recurrent diseases, and as a consequence, traditional etiotropic antibacterial therapy is ineffective. Chronic anal fissures are also a disease which is caused by biofilm forms of bacteria, has a chronic course and is difficult to treat. The sensitivity of planktonic and biofilm forms of bacteria isolated from chronic anal fissures to antibacterial drugs was determined and the method of degradation of biofilm by electrophoresis for the effective treatment of fissures was developed. It was found that the most effective antibiotics against planktonic forms of bacteria were cephalosporins III and IV generations: cefеpime, cefoperazone and ceftazidime. Exceptionally, only bacteria of the genus Enterococcus, which were sensitive to ceftazidime, were found to be 38.9%. The sensitivity of the bacteria to Furamag was from 60.0% to 100.0%, and only P. aeruginosa exhibited resistance in 100.0% of the studied cultures. The number of sensitive to gatifloxacin strains of P. aeruginosa and Enterobacter spp. was 71.4%, all other isolated bacteria were sensitive to this preparation from 77.8% to 100.0%. Among the five studied antiseptics (chlorhexidine, decasan, octinisept, povidone iodine, dioxidine), the greatest antimicrobial activity was found in dioxidine and betadine (povidone iodine) solutions, the sensitivity of the microflora was from 60.0% to 100.0%. We found that the most protected biofilm matrix was P. aeruginosa and Enterococcus spp. We found that the antibiotic which had the best effect on cells in biofilm was fluoroquinoione gatifloxacin. After its influence on the biofilm P. aeruginosa and Enterococcus spp., the number of living cells didn’t exceed lg 1.5 ± 0.02 CFU/cm2 in the area of the biofilm, and S. aureus and E. coli cells were completely inactivated. After the influence of other antibiotics, the number of microbial cells that survived in the biofilm did not exceed lg 2.9 ± 1.6 CFU/cm2 of the area. It was found that after the action of dioxin, the amount of viable microbial cells was up to lg 2.9 ± 1.7 CFU/cm2 of biofilm area. Antiseptics: octine septum, ranopost, decaSan and chlorhexidine exhibited less strong bactericidal action on cells in biofilms, and the number of bacteria that survived after their action ranged from 2.9 ± 1.8 to lg 3.7 ± 2.1 CFU/cm2 of biofilm area. We propose using solution "Dioxysol-Darnitsa" (active substance dioxidine) for local treatment of patients with chronic anal fissures for intracutaneous electrophoresis of the fissure. We established that under the influence of electrophoresis at a current of 0.05–0.10 mA/cm2 of the area of the biofilm with dioxidine, bacteria were not isolated. This indicates on the destruction of the matrix and the effective contact of dioxidine with microbial cells and the manifestation of bactericidal action. Consequently, laboratory microbiological studies indicate that the use of electrophoresis with dioxysole in the treatment of chronic anal fissures is promising.