Microorganisms in raw milk from cows with subclinical mastitis

The microorganisms in raw milk are an important factor in terms of food safety and food waste; and it is significant for the consumption and subsequent processing of milk. The objective of this study was to identify the DNA of pathogenic bacteria in the milk from animals with subclinical mastitis. The studies were carried out using the Real-time PCR technique, using a “Vet-Septoskrin” reagent kit (IDS, Russia), on a “Rotor-Gene 3000” instrument (Australia) in n = 45 milk samples from 35 cows black –motley breed (1 quarter affected in 25 cows, 2 in 10 cows). Milk samples were sampled 50 days post-partum. DNA of the following pathogenic and conditional-pathogenic microorganisms was found in 95.6% of cow’s milk samples: Staphylococcus (Staph) spp. (46.5%), Staph aureus (27.9%), Escherichia coli (16.3%), Streptococcus (Strept) agalactiae 9.3%). The microflora was absent in 4.4% of the samples. The following microorganisms were represented by monoculture (Staph aureus, E. coli) in 19.15% of the samples; in 80.85% of the samples mixed bacterial cultures were found. 40.65% of the mixed bacterial cultures included Staph spp. (Staph epidermidis + Staph saprophyticus + Staph haemolyticus). The other 59.35% of the samples included mixed bacterial cultures of E. coli + Staph spp. (15.65%), Staph aureus + Staph spp. (12.70%), E. coli + Strept agalactiae (12.25%), Staph aureus + E. coli + Staph spp. (10.50%), Staph aureus + Strept agalactiae (8.25%). At the end of the observation period (4 months), 8.57% of cows with subclinical mastitis suffered from clinical mastitis and 57.14% were cured. Our analyses revealed that raw milk of cows with subclinical mastitis can be affected with different groups of bacteria and results of culture will help to choose treatment regimens