“Phenotypic and Genotypic characterization of Staphylococcus species”

Abstract

In the present investigation, The confirmation of 45 strains of coagulase negative Staphylococcus isolates was studied among mastitic cows, buffaloes. 23 from cow milk and 22 from buffalo milk. In addition to 18 S.aureus isolates, 11from cow milk and 7 from buffalo milk. S.aureus was isolated from the examined cow and buffaloes samples in pure culture (61.1 and 38.9 % respectively). CNS were isolated from the examined cow and buffaloes pure cultures was 51.1 and 48.9 % respectively. Identification of isolates was achieved by using convetional identification methods, the API staph ID test (BioMerieux) and PCR amplification. 14 S. xylosus. 12 S. hominis. 7 S. lugdunensis. 6 S. cohnii, 4 S. saprophyticus, 1 S. simulans, 1 S. lentus strains were confirmed. All B lactamase CNS producers (100%) detected from the examined buffaloe milk samples were resistant to penicillin. While 72.7% of B lactamase CNS producers detected from the examined cows were resistant to it. Most of CNS isolates were sensitive to neomycin, gentamicin, florfenicol and erythromycin. Mean while the examined isolates were resistant to cloxacillin, amoxycillin, ampicillin, penicillin and oxacillin. 52.2% and 18.2% CNS isolated from cows and buffaloes respectively were toxin (A) producers, while 4.35% and 4.5% respectively were toxin (A+D) producers, And 4.35% isolated from cows were toxin A+C+D and 4.5% isolated from buffaloes were toxin A+C producers. Sodium Dodecyl Sulfate-Poly Acrylamide Gel Electrophoresis (SDS-PAGE) showed the protein profile analysis of 41 CNS strains. It obvious that protein profile of CNS strains is separated into 1-12 fractions. The proportion of similarity in the samples that were separated ranged between 88% and 97%