MOLECULAR CHARACTERIZATION OF STAPHYLOCOCCUS AUREUS ISOLATES RECOVERED FROM NATURAL CASES OF SUBCLINICAL MASTITIS IN CHOLISTANI CATTLE AND THEIR ANTIBACTERIAL SUSCEPTIBILITY

Mastitis being the most significant disease of dairy animals largely affects the farm economics by decreasing milk production, and increasing the treatment costs (Mohammadian, 2011; Singh et al., 2015). Mastitis is a multi-etiological disease, however, Staphylococcus aureus is the most important and lethal agent (Jaradat et al., 2014) that causes chronic and deep infections in mammary tissue and becomes difficult to treat successfully and it is responsible for dairy scourge in the livestock industry (Hussain et al., 2012a; Raza et al., 2013). Staphylococcus aureus is the most commonly isolated pathogen in subclinical mastitis (Amin et al., 2011; Dieser et al., 2014; Cengiz et al., 2015). Economic significance to dairy business on account of Staphylococcal udder infection results from the subclinical mastitis escorted with a decrease in milk quantity and quality (He et al., 2014; Kucukonder et al., 2015). Staphylococcus aureus remains a major issue under different tropical and sub-tropical management situations. Staphylococcus aureus possesses several proteins which are virulent in nature and transmits simply in lactating animals (Maksymiec and Mikolajczyk, 2012). Coagulase and spa proteins are virulence factors found in S. aureus which induces mastitis (Karahan et al., 2011) and spa is a surface protein of cell wall that impairs the opsonisation and the phagocytosis process by binding with IgG antibody (Gao and Stewart, 2004). Eradication of S. aureus is very difficult despite the conduction of intense measures for control purpose. Consequently, control of the S. aureus mastitis has fundamental importance and remains as essential (Waller et al., 2009; Hussain et al., 2013b; Jaradat et al., 2014). Several approaches regarding phenotyping and genotyping procedure are being used to sub-type the Staphylococcus Pak. J. Agri. Sci., Vol. 53(4), xxx-xxx; 2016 ISSN (Print) 0552-9034, ISSN (Online) 2076-0906 DOI: 10.21162/PAKJAS/16.4828 http://www.pakjas.com.pk