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The aim of the present study was to assess the haemolytic and proteolytic activity of coagulase- negative staphylococci (CNS) isolated from cows with mastitis. The study was conducted on 100 CNS strains: S. xylosus (n=28), S.chromogenes (n=26), S.haemolyticus (n=25), S. sciuri (n=14), S. warneri (n=4), S.hominis (n=2), S.saprophyticus (n=1); 22 CNS were isolated from cows with clinical mastitis and 78 from those with subclinical mastitis. The CNS studied showed the ability to produce only α-haemolysin and belonged to one strain – S. haemolyticus (21.0% of isolated CNS strains). Haemolysin-positive CNS were responsible for both clinical and subclinical mastitis (22.7% and 20.5%, respectively). The ability to produce protease was found in 31.0% of CNS belonging to two strains: S. chromogenes and S. sciuri. Protease-positive CNS were the etiological factor of both clinical and subclinical mastitis (31.8% and 30.8%, respectively). All S. xylosus, S. warneri, S. hominis, and S. saprophyticus strains were found protease-negative and haemolysin-negative, irrespective of whether they caused clinical or subclinical mastitis in cows.
Thirty-seven cows affected with clinical mastitis (51 quarters) were injected iv with a single 0.02 mg/kg dose of Lydium-KLP. Fifteen cows were injected with both Lydium-KLP at the same dose given twice at a 24-hour interval and intramammary infusion of the agent (0.2 mg per quarter). It was found that the efficacy of the agent depended on the number of somatic cells in the mastitic milk and on their phagocytic activity at the beginning of the experiment.
The importance of mastitis in small ruminants is important from the point of view of 3 perspectives: economic (mortality of animals, treatment costs, reduced quantity and quality of milk); hygienic (the risk of infection or poisoning of consumers by consuming infected milk), and legal (definitions of bacteriological milk quality). Coagulase-negative staphylococci are the most prevalent pathogens of the mammary gland in sheep and goats with subclinical mastitis (affecting from 45 to 48% in sheep and from 60 to 80.7% in goats). Prevalence of clinical mastitis in small ruminants is usually below 5%. Several pathogens can cause mastitis, but Staphylococcus spp. are the most frequently diagnosed causal microorganisms of intramammary infections in goats and sheep. Somatic cell counts in milk of dairy ewes can be used to define subclinical mastitis and a threshold of about 200,000 to 400,000 cells/ml will accurately identify most infected ewes. In ewe milk somatic cell counts between 300,000 cells/ml and 1,000,000 cells/ml cause changes in the composition and plasmin activity, and suggest that milk secretion is in a period of transition from normal to mastitic milk. In goats infected glands also lead to an increase in somatic cell counts; however, increased somatic cell counts in milk are also caused by other non-infection factors, such as estrus, season of milking, milk yield or stage of lactation. A standard tool in the diagnosis of mastitis for small ruminants is bacteriological examination of milk. During milking of small ruminants there is usually a transmission of Gram-positive bacteria, mainly Staphylococci. Therefore, the control of mastitis in small ruminants should take into account the optimal milking routine and milking hygiene. In particularly justified cases and the large prevalence of disease antibiotic treatment should be administered in the dry-period.
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