The present study was performed on a total of 124 milk samples from
small scale producers, farmers and markets at El-Menofyia
Governorate.The prevalence of Streptococcus species in the examined
samples was (65.3%),where S. agalctiae, S. dysgalactiae, S. uberis, S.
pyogenes and S. pneumoniae were 28.2%, 11.3%,16.1%, 8.9% and
0.8%; respectively. The antibiogram for Streptococcus spp. revealed
that vancomycin and erythromycin were the most proper antibiotics
with the highest in vitro efficiency against isolated Streptococcus
spp., but were resistant to cefatriaxone and
chlormphenicol.Additionally, S. agalactiae and S.dysgalactiae were
sensitive to penicillin, ofloxacin ;respctively.But S.uberis was
sensitive to amoxicillin and clindamycin. By using PCR, virulence
gene hyalurinidase (hyl) was detected in 25% of S. agalactiae, while
monokine induced by IFN-gamma (mig) gene was detected in 100%
of S. dysgalactiae. Also plasminogen activator(pauA) gene was
detected in 100% of S. uberis isolates