Background and Aim: Mastitis is one of the most important diseases of cows and the most expensive pathology for the dairy industry. Therefore, this study was conducted to explore the role of microorganisms isolated from cows with mastitis in the formation of biofilms under the conditions of farm biogeocenosis in the Moscow region.
Materials and Methods: Periodic visits to 12 farms in the Moscow region were conducted to explore the microbial profile of the udder of cows with mastitis. During the visits, 103 milk samples from sick animals were collected and examined. Through microbiological analyses, 486 cultures of microorganisms were identified, which are assigned to 11 genera. Mastitis in cows is caused not only by a single pathogen but also by microbial associations, which included two to seven microbial isolates.
Results: It was observed that 309 isolates (63.6%) from the total number of isolated microorganisms could form a biofilm. The ability to form biofilms was most frequently observed in Staphylococcus aureus (18.8%), Escherichia coli (11.9%), and Staphylococcus uberis (11.7%) cultures from the total number of biofilm-forming microbial cultures. Low biofilm-forming ability among the isolated microorganisms was found in lactobacilli, wherein only 20 (22.5%) Lactobacillus strains had the ability to form biofilms. The isolated microorganisms exhibited different sensitivities to antimicrobial agents, which cause difficulty in selecting an antimicrobial agent that would act on all aspects of the parasitocenosis.
Conclusion: A high proportion of microorganisms isolated from cows with mastitis have the ability to form biofilms. The isolated microorganisms exhibited different and highly heterogeneous sensitivity to the action of antimicrobial drugs. This causes difficulty in using these tools for the effective control of mastitis in cows, which is frequently caused by pathogenic associations of microbial biofilms. Therefore, it is important to explore novel and more effective methods to combat this disease.
Florfenicol was administered to five heifers intramuscularly at a dose rate of 20 mg/kg bwt and following wash‐out period, subcutaneously at a dose rate of 40 mg/kg bwt. Blood plasma samples were collected from heifers before injection of florfenicol and up to 120 h after intramuscular (IM) injection and up to 264 h after subcutaneous (SC) injection. Florfenicol concentrations in plasma were measured by high‐performance liquid chromatography with mass‐spectrometric detection. Pharmacokinetics of florfenicol was estimated using non‐compartment analysis. Mean maximum plasma concentration, area under the concentration–time curve and elimination half‐life for florfenicol were 3.2 μg/ml, 101.5 μg × h/ml and 24.5 h, respectively, after IM injection at 20 mg/kg bwt, and 2.7 μg/ml, 194.5 μg × h/ml and 103.8 h, respectively, after SC injection at 40 mg/kg bwt. The obtained results indicated that both administration routes provided comparable bioavailability, whereas SC route was attributed with lower peak levels and markedly slower absorption of florfenicol from injection site. Both administration routes provided plasma florfenicol levels which are expected to be effective against prevalent infectious agents of cattle.
This article describes an innovative method for regulating populations of blood-sucking Diptera that parasitize cows. This relates to the field of agriculture, namely to the means of protecting farm animals from insect bites, and can be used to protect farm animals from ectoparasites during the period of their grazing. To produce these products, the polymer was treated with an impregnating solution containing pyrethroid (2-26% by weight of the untreated polymer product), an inhibitor of arthropod detoxification enzyme systems (0.5-20.0%), a lubricant (0.1-3.0%) and an aliphatic ketone (5-90%). The method was simple in execution, and the insecticidal acaricidal polymer products obtained according to the method had a long shelf life of at least seven months. The products were resistant to environmental influences and did not lead to environmental pollution with excess active substances.
Keywords: Ear tags, s-fenvalerate, piperonyl butoxide, Diptera
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