A method for determining whether bacteria in a sample obtained from a subject at a point of care in a clinical setting is susceptible to an antibiotic, within a time period associated with a point of care. The method includes measuring a bioluminescent indication from a first test sample based on released ATP to determine a characteristic associated with the bioluminescent indication and comparing the characteristic associated with the bioluminescent indication to a first threshold. The method includes determining whether a bacteria is present by comparing the difference between a characteristic associated with a first confirmatory bioluminescent signal and a characteristic associated with a second confirmatory bioluminescent signal to an confirmatory threshold. The method includes determining that bacteria is susceptible to an antibiotic by comparing a difference between a characteristic associated with a second bioluminescent signal and a characteristic associated with the first bioluminescent signal to a s
