In the present study, we employed flow cytometry to evaluate the level of parasitemia of Babesia gibsoni infecting canine erythrocytes in vivo and in vitro by using fluorescent nucleic acid staining. Peripheral blood samples from a B. gibsoni-infected dog and cultured B. gibsoni parasitizing in canine erythrocytes were stained with a membrane-permeable fluorescent nucleic acid stain, SYTO16. In this study, we utilized normal canine erythrocytes (LK erythrocytes) and canine erythrocytes containing high concentrations of potassium, reduced glutathione, and some free amino acids (HK erythrocytes) as host cells for culture. In vivo parasitized cells were discriminated completely from unparasitized cells and a correlation (r=0.998) between the percentage of SYTO16-positive cells and parasitemia in vivo was observed. On the other hand, in vitro erythrocytes could not be divided clearly into parasitized and unparasitized cells. However, when LK erythrocytes were used as host cells, the percentage of SYTO16-positive cells was the almost same as, and was well correlated (r=0.932) with the level of parasitemia. When HK erythrocytes were used as host cells, the percentage of SYTO16-positive cells was almost half of, but was correlated (r=0.982) with the level of parasitemia. Therefore, we attempted to observe the changes in the percentage of parasitized cells after treatment with antiprotozoal drug or mitochondria inhibitors by using flow cytometry. The changes in the percentage of SYTO16-positive cells corresponded well with the changes of the level of parasitemia when the parasites in HK erythrocytes were cultured with each compound. The present results suggest that flow cytometric detection using SYTO16 is a rapid and reliable method for monitoring parasitemia both in vivo and in vitro.

The necessity of creation of the optimal conditions for production of high-quality dairy products was conditional upon the fact that milk is very unstable by its chemical and physical indicators biological liquid. There is no point in improving milk quality after the realized production. Results of the realized in the conditions of the Republic of Belarus evaluation of milk according to the sanitary and hygienic indices for the further improvement of its quality were presented. According to the data on milk purchasing it noted that in Belarus there was stated a noticeable reduction of milk quality in accordance with its grade of quality. Throughout the last years the relative density of realization of the premium quality milk was less than 50% (46,5% - in 2005, 48% - in 2006), and at the same time, the volume of sales of the second second-rate quality milk reduced on 7,6%, and volume of off-grade milk - on 0,7%. Milk quality at the studied in course of investigation dairy farms in the majority of cases was conditional upon such indicators as base-titratable acidity, bacterial number and quantity of somatic cells in milk. Titrate acidity indices in over than 36% of milk does not correspond in to standards of the Republic of Belarus. Evaluation of bacterial number in the produced milk showed that its main production volume (65,2%) corresponded to the first and second grades and 6,7% were off-grade quality. Somatic cells content in the studied milk samples in 27% corresponded to the extra fine grade, and only about 2% of the analysed milk samples corresponded to off-grade milk