instruction: what was the name of the organism found at the first blood, venipuncture test of patient 031-23724 until 09/2104?
response: SELECT microlab.organism FROM microlab WHERE microlab.patientunitstayid IN (SELECT patient.patientunitstayid FROM patient WHERE patient.patienthealthsystemstayid IN (SELECT patient.patienthealthsystemstayid FROM patient WHERE patient.uniquepid = '031-23724')) AND microlab.culturesite = 'blood, venipuncture' AND STRFTIME('%y-%m', microlab.culturetakentime) <= '2104-09' ORDER BY microlab.culturetakentime LIMIT 1