Detection Of Intracellular Adhesion Gene (Icaa And Icad) And Biofilm Formation Staphylococcus Aureus Isolates From Mastitis Milk Of Cow

In the present study, a total of 75 mastitis milk samples were collected from cow and were analyzed for the presence of S.aureus. The obtained results indicate that this bacterium observed in 26.66%. The study of antibiotic susceptibility test to 9 different antibiotics showed that S. aureus was 100% resistant to penicillin and 100% sensitive to Vancomycin, Gentamycin , Clarithromycin and Chloramphenicol . Whereas for cefoxitin (alternative to methicillin) resistance was 50%.There were a variable resistance percentage for the rest of antibiotics: Tetracycline (30%), Ciprofloxacin and Clindamycin (22%). The biofilm-forming ability of S. aureus was evaluated via microtiter plates and the result revealed that, all the studied isolates were either moderate biofilm producer or weak biofilm producer while the non-biofilm producer and strong biofilm producer were not detected among the tested isolate. PCR analysis was applied to DNA extracted from S.aureus isolates from milk samples .The results of PCR assay revealed that all S.aureus isolates gave positive results for both icaA and icaD genes (100%) with Product size 151 and 211 bp, respectively. Results of this study indicate that biofilm producing S.aureus have a major role player on the occurrence of bovine mastitis in addition, there were high prevalence of MRSA isolates (50%) in mastitis milk at the study area.