In a study conducted by Lee Health System clinicians at Lee Memorial Hospital, Fort Myers, Florida, T2Bacteria® Panel research use only (RUO) results were compared to conventional standard of care culture results. This comparison allows an analysis of how the use of the T2Bacteria Panel could have potentially changed clinical practice and outcomes.
53-year-old immunocompromised, morbidly obese female with recent history of surgery to drain an intra-abdominal abscess
Presentation in the Emergency Room: Patient presented at the emergency department 8 days post-op with fever, chills and abdominal pain. She was started on empiric antibiotics and admitted to the emergency room. Patient continued on empiric IV antibiotic therapy for 5 days, then transitioned to 2 days of oral antibiotics prior to discharge.
Empiric Therapy Decision: Patient was started on linezolid, aztreonam, and metronidazole. Linezolid was chosen for gram-positive coverage because vancomycin dosing is very difficult for obese patients. Patient had allergies to penicillin and bactrim. Aztreonam was chosen for gram-negative coverage as the piperacillin-tazobactam substitute because of the patient’s allergy. Metronidazole was chosen for anerobic coverage.
Culture Results: Blood and urine cultures were negative.
Paired T2Bacteria Result: Positive for E. coli and P. aeruginosa and negative for S. aureus, E. faecium, and K. pneumoniae.
Case Study Analysis: The T2Bacteria Panel result could have been a powerful aid in stewardship through the identification of E. coli and P. aeruginosa and the rule out of S. aureus (and therefore rule out of MRSA).
While the empiric choice was effective and the patient responded well, it was also broader than necessary, as it covered for MRSA, a primary species of concern at this community hospital.
The negative S. aureus result meant that the patient did not have MRSA and therefore linezolid could have been discontinued after the first dose when the T2Bacteria result was available. The 4.5 day reduction in linezolid ($289 per dose and two doses per day) amounts to an estimated savings of $2,600 as these antibiotics were not needed.
The patient’s therapy could have been more targeted by switching to meropenem to cover E. coli and P. aeruginosa, as well as providing the anaerobic coverage needed. The penicillin allergy history precluded the utilization of a more narrow beta-lactam or beta-lactam agent combination.