This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Staphylococci, Subject name: Microbiology
[{'content': 'Blood culture of a patient shows growth of gram positive cocci which are catalase positive and coagulase negative. The patient was on a CVP line last week. The most likely etiological agent is? \nSelect and explain. \nA. Staphylococcus aureus, B. Staphylococcus epidermidis, C. Streptococcus pyogenes, D. Enterococcus faecalis', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. (b) Staphylococcus epidermidisRef: Microbiology by Ananthanarayati and Paniker 8th ed. /655, 679STAPHYLOCOCCUS* Gram positive cocci, coagulase and Catalase positive: Staphylococcus aureus* Gram positive cocci, Coagulase negative: Staphylococcus epidermidis and saprophyticus.* Staph. Epidermis infect most commonly through artificial device like: IV canula, Prosthetic device, shunts and implants.* MCC of catheter associated blood stream infection: Staph. Epidermis* MC organism causing prosthetic valve endocarditits: Staph. Epidermis.', 'role': 'assistant'}]