Close this search box.
Close this search box.

De-escalation of Therapy Before Blood Culture Result is Returned

A severely dehydrated elderly patient was admitted for septic shock overnight.


This case highlights not only T2Bacteria’s ability to rapidly identify specific bacterial pathogens in whole blood but also the capability to detect the causative organism in the presence of antibiotics where blood cultures remained negative, as well as an opportunity to use the result to de-escalate therapy.


A severely dehydrated elderly patient was admitted for septic shock overnight. They presented with a fever of 102.3, WBC of 19.9, and a lactic acid of 6.5.  Upon presentation in the Emergency Room, blood cultures were taken, and they were started on broad-spectrum, empiric antimicrobials, and transferred to the ICU.  Urine cultures were taken in the morning because the suspected source of infection was genitourinary, and a T2Bacteria was run in addition to the second set of blood cultures.

Patient Selection Criteria

A septic patient presenting in the Emergency Department

Evaluation and Treatment Decision

The patient was started on piperacillin/tazobactam and levofloxacin

T2Bacteria Panel Result

Positive for E.coli

Blood Culture

Both sets of blood cultures- No growth

Urine Culture

No growth


Indicative of a urinary infection

Decision making based on the T2Bacteria Result

Overnight blood cultures were obtained for an infectious workup at the time of admission, and in the early morning, a T2Bacteria was taken with the second set of blood cultures.

Despite the pending blood cultures at the time of the positive T2 result, the patient was de-escalated to a narrower spectrum antimicrobial, ceftriaxone, within 24 hours of the patient being admitted. The patient improved and was changed to oral therapy on day 5 of therapy and later discharged.

According to the CDC, of the 154 million prescriptions for antibiotics written in doctors’ offices and emergency departments each year, 30% are unnecessary.12