Catalase positive coagulase negative beta hemolytic bacteria-
**Core Concept**
The question is testing the identification of a specific type of bacteria based on its biochemical and hemolytic properties. The bacteria in question are catalase positive, coagulase negative, and beta-hemolytic, which means they break down hydrogen peroxide, do not produce a coagulase enzyme, and cause complete hemolysis of red blood cells, respectively.
**Why the Correct Answer is Right**
The correct answer is likely a species of Staphylococcus, specifically Staphylococcus aureus. This bacterium is catalase positive, meaning it contains the enzyme catalase that breaks down hydrogen peroxide into water and oxygen. It is also coagulase negative, which distinguishes it from Staphylococcus aureus, which is coagulase positive. The beta-hemolytic pattern is consistent with S. aureus, which causes complete hemolysis of red blood cells on agar plates.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is likely incorrect because it does not match the biochemical and hemolytic properties of the bacteria in question. Other Staphylococcus species, such as Staphylococcus epidermidis, may be catalase positive and coagulase negative, but they typically exhibit different hemolytic patterns.
**Option B:** This option is likely incorrect because it does not match the biochemical and hemolytic properties of the bacteria in question. Enterococci, such as Enterococcus faecalis, are typically catalase negative and may exhibit different hemolytic patterns.
**Option C:** This option is likely incorrect because it does not match the biochemical and hemolytic properties of the bacteria in question. Streptococci, such as Streptococcus pyogenes, are typically catalase negative and may exhibit different hemolytic patterns.
**Option D:** This option is likely incorrect because it does not match the biochemical and hemolytic properties of the bacteria in question. Other bacteria, such as E. coli, may exhibit different biochemical and hemolytic properties.
**Clinical Pearl / High-Yield Fact**
Staphylococcus aureus is a common cause of skin and soft tissue infections, as well as more severe conditions such as endocarditis and sepsis. It is often resistant to methicillin and other antibiotics, making it a significant public health concern.
**Correct Answer: C. Staphylococcus aureus**