A patient in an ICU is on central venous line for the past one week. He is on ceftazidime and amikacin. After 7 days of antibiotics he develops a spike of fever and his blood culture is positive for gram positive cocci arranged in pairs, which are catalase negative. Following this vancomycin was staed but the culture remained positive for the same organism even after 10 days of therapy. The most likely organism causing this infection is-:
Catalase negative, Gram positive cocci in pair - indicates that they are Enterococcus . Enterococci (earlier known as group d streptococci) are commonly seen in hospital acquired infections and they are resistant to cephalosporins and even to vancomycin.
Staphylococcus aureus
Virdans streptococci
Enterococcus faecalis
Coagulase negative staphylococcus
Systemic Bacteriology Pa 1 (Gram Positive Cocci, Gram Negative Cocci)