مرکز منطقه ای اطلاع رساني علوم و فناوري -

چكيده لاتين :

Staphylococci isolated from 98 mastitic cow’s milk samples were analyzed for the production of alpha, beta and delta-hemolysin on sheep, bovine and horse red blood cells and in vitro susceptibility to several antimicrobial agents. Out of a total of 18 isolated strains, 100% demonstrated hemolytic activity either alone or in combined forms. Among 8 isolates of S. aureus 3 isolates produced alpha/beta and 5 produced alpha/beta/delta hemolysins. From 10 isolates of coagulase-negative staphylococci (CNS), 2 alpha , 2 delta , and 4 alpha/beta/delta hemolysins producing isolates were confirmed. S. aureus isolates were resistant to cloxacillin (100%), penicillin (87%) and ampicillin (62.5%). CNSs showed resistance only to amoxicillin (60%). The results suggest that a cow’s infected mammary glands are an important reservoir of hemolytic staphylococci. A high degree of S. aureus antimicrobial resistances was detected.