Abstract
The current study was carried out on 10 flocks of sheep and goats in Al-Ameria district, Alexandria Province during the period extended from January 2016 till December 2017. A total of 500 milk and environmental samples were collected and examined for isolation and identification of Streptococcus species especially those accused to be a reason for environmental mastitis. The samples were divided into; 300 milk samples of clinically suspected mastitic cases of sheep (150 samples) and goats (150 samples), 100 bedding samples of different sites of yards of sheep (50 samples) and goats (50 samples) particularly those wetted areas with high moisture and organic matter load, finally about 100 representative water samples were collected from water in front of the animals in different sites of yards of sheep (50 samples) and goats (50 samples) by a rate of 10 samples per visit. The obtained results clarified that the total prevalence of Streptococci in the examined samples of sheep and goats farms was 29.20% and 31.20%, respectively. In addition, the prevalence of Streptococci in milk, bedding and water samples was 25.33%, 46%, and 24%, respectively in sheep farms while it recorded 28.67%, 38% and 32%, respectively in goat farms. Biochemical identification of the recovered isolates revealed the presence of Str. agalactiae, Str. dysgalactiae, Str. uberis, Str. canis, Str. faecalis and Str. pyogenes with different rates. Antibiogram test for Str. dysgalactiae and Str. uberis was performed and clarified that Str. dysgalactiae was highly sensitive to Amoxicillin and Erythromycin while it was weak sensitive for Flumequine, Doxycycline and Sulphamethoxazole-Trimethoprim. On the other hand, Str. uberis was found to be quite sensitive to Ciprofloxacin and Amoxicillin while it was resistant to Gentamycin, Flumequine, Enrofloxacin, Doxycycline, Oxytetracycline and Erythromycin. Finally, multiplex PCR was applied for simultaneous detection of Str. dysgalactiae and Str. uberis.

Key words: Streptococci, Environmental mastitis, Prevalence, Antibiogram, PCR