Haemolytic and proteolytic activity of coagulase-negative staphylococci isolated from mastitis cows

Abstract

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.

Application of Matrix-assisted Laser Desorption Ionization Time-of-flight Mass Spectrometry for Identification of Coagulase-negative Staphylococci Isolated from Milk of Cows with Subclinical Mastitis

“…Staphylococcus equorum, S. warneri and S. lentus are less frequently present in such material according to the literature data (Anaya-López et al 2006, Bochniarz et al 2012. The available literature fails to offer data concerning subclinical infections in the udders of cows caused by S. vitilinus, even though in the present study these microorganisms were identified by MALDI-TOF MS in 15% of the disease cases.…”

Virulence factors and ability of staphylococci from bovine milk and the cowshed environment to biofilm formation

“…The pathogenicity of staphylococci is related to the production of several virulence factors responsible for the development of disease process ( factors were found in S. aureus strains isolated from bovine mastitis (Silva et al 2005, Hata et al 2006, Peles et al 2007, Melchior et al 2009, Capurro et al 2010, but only few studies involved search of virulence factors of CNS isolated from bovine mastitis (Zhang andMaddox 2000, Bochniarz andWawron 2012). Virulence factors of staphylococci have been investigated by measuring phenotypic expression of products associated with virulence (Taponen and Pyörälä 2009).…”

“…CNS strains isolated from milk of cows with mastitis produced proteases and haemolysins (Zhang andMaddox 2000, Bochniarz andWawron 2012). Moreover, biofilm formation has been proposed as an important virulence factor of CNS, by which mastitis-causing staphylococci avoid the immune response of the cow and cause persistent intramammary infections (Simojoki et al 2012).…”

Detection of methicillin resistant and slime factor production of coagulase negative Staphylococcus spp. in bovine clinical mastitis by using PCR

“…In the present work the presence of the mecA gene was investigated by PCR, the incidence of methicillin resistance in the tested MRCoNS was 50% [3/6] by the presence of mecA gene, as shown in Table [ 4] and Fig. [3].…”

“…The pathogenic mechanisms of CoNS are expressed by two parameters: invasiveness [ability to permeate through protective barriers, to adhere to host cells and to form a biofilm] and toxicity [capacity to produce enzymes and toxins, including haemolysins and proteases], [4] .…”