Abstract
This study aimed to throw the light on the incidence of coagulase negative staphylococcus (CNS) in clinical mastitis and its surrounded people and if there is a relationships between the incidence of CNS in mastitic cows and in surrounded peoples.
The samples of human and animals collected from the Talaat Mustafa dairy farm located in Noubareia Alexandria Egypt at Cairo-Alexandria Desert Road (Private farm) and the worker act in this farm. These samples were examined for mastitis by collecting mastitic milk
In this study a total number of 50 lactating Fresian cows were investigated for clinical mastitis .
The pharyngeal swabs (50 samples) collected from the farmers that closely related and intact with the cattle. The age of this individuals ranged from 15 – 60 years for determination the relationships between the bacteria isolated from the milk and human. The number of pharyngeal swabs samples were 50 samples.
The samples isolated from mastitis cows were examined bacteriologically: 20 out of 50 samples(40%) were positive for staphylococcus. 8 out of 20 samples (40%)were coagulase positive staphylococcus while 12 out of 20 samples (60%) were coagulase negative staphylococcus.
The samples from human contact (50 samples) : 15 out of 50(30%) samples were positive for staphylococcus and7 out of 15 (70%) of samples were coagulase positive while 8 out of 15 (53%) of samples were coagulase negative staphylococcus.
The coagulase negative staphylococcus isolates were very high sensitive to ciprofloxacin and amikacin while the intermediate drugs were ampicillin/fnlbacterin and gentamycin and the resistant drugs were amoxicillin and trimethoprime+ sulphamethaxol.

Key words: This study concluded that, the incidence of coagulase negative staphylococci higher than that coagulase positive staphylococci Coagulase-negative staphylococci (CoNS) belong to saprophytic microbiota on the skin and mucous membranes, its incidence in winter higher than that, of summer season, it causes changes in milk consistency, its colour , it can causes respiratory manifestation in surrounded people and causes changes in the colour and consisten