This is an experimental study of participants who had positive blood culture to compare time to appropriate antibiotic between using Microarray Assay and Mass Spectrometry to bacterial Identification.

Between June to Dec 2018, 200 participants those met the eligibility criteria were enrolled in this study that is a quasi experimental study. All participants were empirical antibiotic therapy by infectious physician. 100 patients in Pre-intervention group had bacterial identification by Mass spectrometry technique from bacterial colony and 100 patients in Post-intervention group had bacterial identification by Microarray assay from blood culture. Antibiotic adjustment were considered after bacterial identification and result of antibiotic susceptibility testing. Then all participants were re-evaluated outcome after treatment. Finally, the results were ready to analysis in January 2019.

Inclusion Criteria:

• Age ≥ 18 year old with positive hemoculture between June 2018 and Dec 2018
• Internal medicine wards patients at Maharaj Nakorn Chiang Mai Hospital
• Ability to provide informed consent

Exclusion Criteria:

• Suspected contaminated positive blood culture
• Bacteremia cause by more than two species of bacteria, as suspected from the gram staining examinations
• Terminally ill patients