Abstract
Septic arthritis in poultry is related to massive losses in poultry industry. Staphylococcus aureus is one of the most common bacteria recovered from leg and joint infections of poultry .Staphylococcal infection requires multitude of virulence factors that intricately coordinated and regulated such as microbial surface components adhesive matrix molecules (MSCRAMMs). Members of this family (clfA- clfB- cna- fnbA-fnbB) genes allow colonization of wounds and skin surface within body associated with specific diseases such as arthritis .Thus, cell- wall anchored proteins and genes encoding them are essential virulence factors for the survival of S.aureus in both commensal state and invasive infections and targeting them with vaccines could combat S.aureus infections .
The aim of this study was to screen the S.aureus isolated from chicken clinically arthritic hock joint synovial fluid , collected from different broiler chickens farms for the presence of( MSCRAMMs )genes. The samples were cultivated on mannitol salt media and biochemically identified for S.aureus.The results in this study revealed that out of total 70 isolates suspected to be Staphylococci, 37 isolates were positive for tube coagulase test (TCT) at a percentage of (52.8%). The antimicrobial sensitivity pattern of Staphylococcus aureus against 12 commercially available antibiotic discs showed 100 % resistance to oxytetracycline followed by Amoxicillin (71.43%), Erythromycin (57.14%), Chloramphenicol (73.33%), Norfloxacin (14.29%), Tetracycline (42.86), Sulphamethoxazol (42.86%), Gentamicin (42.86%), Ampicillin (42.86%), kanamycin (28.57),cephalotin (28.57) ,deoxycycline (0%) and The least was observed with chloramphenicol (0%). .The result of PCR amplification of MSCRAMMs genes of S.aureus(clfA- clfB- cna- fnbA-fnbB) reveled that all isolates (7) were positive for clfA and fnbA at a percentage of (100%) and negative for clfB and fnbB and cna (0%) genes .

Key words: Staphylococcus aureus Septic arthritis chickens MSCRAMMs PCR