COAGULASE-NEGATIVE Staphylococcus SPECIES ASSOCIATED WITH SUBCLINICAL BOVINE MASTITIS: VIRULENCE FACTORS.

FILIPUZZI L; BONETTO C; CHALLIER E; PELLEGRINO M.; BOGNI C.; ODIERNO L.; RASPANTI C.

San Miguel de Tucumán

Congreso; THIRD JOINT MEETING OF THE BIOLOGY SOCIETIES OF ARGENTINA; 2015

Sociedad de Biología de Córdoba, Sociedad Argentina de Biología, Sociedad de Biología de Cuyo

Coagulase-negative Staphylococcus (CNS) are emerging as potential bacteria responsible for bovine intramammary infections (IMI) in modern dairy farms. Different species of CNS can produce various toxins and enzymes that contribute to its virulence. Our objective was to determine the presence of virulence factors in CNS species with clinical significance in IMI. A total of 37 S. chromogenes and 34 S. haemolyticus isolated from milk samples from cows with subclinical mastitis were investigated for their ability to produce biofilm, protease, lipase, DNase and -hemolysin, in micro titer plates, plates with trypticase soy agar-2% skim milk, Baird-Parker supplemented with yolk, DNase agar and blood agar 5%, respectively. The presence of genes encoding superantigens (SAgs) sea, seb, sec, seln, selq, seh and sej was investigated by PCR. Six different combinations of SAgs genes were detected. The most prevalent combination of genes (SAgs sea and sec) was found in S. chromogenes.A higher percentage of strains of S. chromogenes than of S. haemolyticus showed activity of proteases, lipase and DNase, whereas the ratio was reversed for -hemolysin production. High percentages of biofilm forming strains for both species were observed. The isolates analyzed showed the co-expression of several virulence factors, both genotypically and phenotypically, which is relevant for the design of control and prevention measures against CNS mastitis.