Production of slime by coagulase-negative staphylococci (CNS) isolated from clinical and subclinical mastitis in cows

The aim of the study was to evaluate the slime-producing ability of coagulase-negative staphylococci (CNS) isolated from clinical and subclinical mastitis in cows. The study was carried out on 100 isolates of CNS obtained from milk of 86 cows from farms located in the Lublin region (Poland). Slime-producing ability was observed in over half of coagulase-negative staphylococci (54.0% of isolated CNS), including 19 isolates of methicillin-resistant staphylococci (95.5% of all MRCNS). Of 22 isolates of CNS responsible for the clinical form of mastitis, 20 isolates (90.9%) produced slime: S. xylosus (7 isolates), S. haemolyticus (6 isolates), S. chromogenes (4 isolates), and S. sciuri (3 isolates), including 9 isolates of MRCNS (45.0%). The remaining 34 isolates of CNS (43.6%) with the ability to produce this exopolysaccharide were isolated from the milk of cows with subclinical form of mastitis: S. xylosus (12 isolates), S. sciuri (9 isolates), S. chromogenes (6 isolates), S. haemolyticus (3 isolates), S. warneri (3 isolates) and S. saprophyticus (1 isolate), including 10 isolates of MRCNS (12.8%).