Bacteriological and Molecular Studies on Streptococcus Species in Horses.

Abstract

In the present study 150 swabs "100 nasal swabs and 50 pus swabs" were collected from horses suffered clinically from strangles symptoms for examination of Streptococcus spp. The microbiological and biochemical results revealed that there were 2 S.equi isolates" all from pus swabs and 2 S.zooepidemicus isolates" one from nasal swabs and one from pus swabs " , these result confirmed serologically by using specific antisera and also molecularly by using PCR with specific primers for each species. Antibiogram for the recovered S.equi and S.zooepidemicus isolates showed that they were sensitive for Penicillin " except one isolates of S.zooepidemicus "and cephalosporins " except one isolates of S.equi " ., while they show high resistance for bacitracin , erythromycin , tetracycline and amikacin. Three essential oils (cinnamon, anise and oreganium) were tested for their antimicrobial activity against S.equi and S.zooepidemicus . Results were recorded that cinnamon oil completely inhibited the growth of all the tested bacterial isolates (100%) at a concentration of 3% and (50%) at a concentration of 2%, on contrary, 1% concentration had no effect on all the tested isolates , while anise oil did not show any growth inhibitory effect at any concentration used in the present study (1%, 2%, 3%, 4%, 5% and 6%), In other hand oreganium oil exerted a strong growth inhibitory effect on Streptococcus isolates at concentration of 1% (100%). while at 0.5% concentration has no effect.