Bacteriological and molecular detection of Staphylococcus Aureussuperantigenic toxin genes in women ,cows and buffaloes milk

الملخص EN

A total of 300 random samples of milk represented by women, cows and buffaloes (100 for each) were examined by conventional bacteriology, serology and molecular biology tests for the presence of Staphylococcus aureus and its super antigenic toxin and its relation to methicillin-resistance.Positive bacterial isolation was observed in 82(27.3%.) milk samples,including37 (37%) cows, 30 (30%) women and 15 (15%) buffaloes samples.

By using latex agglutination test,all buffaloes milk S.

aureus isolatesexhibitedpositive results(100% ,n=15)followed by isolates of women(83.1%,n=25)and cows(81.1%,n=30) with an overall percentage(23.3%,n=70.).

Amplification of S aureus species, staphylococcal superantigenic toxin (sea, seb and sec) and methicillin-resistant S.

aureus(mecA) gene using Polymerase Chain Reaction (PCR) revealed that, 82/300 (27.3%) of the total examined milk samples were positive for bothspecies(nuc)and resistance(mecA) genes.

While, sea positive results exhibited by 5 (38.5)%) cows milkisolates .Both women and buffaloesmilk isolatesshowedsebpositive resultsin a percentage of 55.5% (5 isolates for each),sec was not producedby women milk isolates and appeared in cows and buffaloes milk isolates (7.7 and 11.1% respectively).Further confirmation for the S aureus diagnosis was performed by sequencing analysis and BLAST comparative analysis, the results of this analysis revealed that partial nucgene sequences of local tested isolates of S.

ureusshowed 100% sequence identity with published data of S.aureus(strain 08-02300, coStaphylococcusaureusmplete genome and Staphylococcus aureus isolate 22_LA_562 genome assembly, chromosome: I