what was the organism found in the first sputum microbiological test of patient 92642 until 05/2100?
select microbiologyevents.org_name from microbiologyevents where microbiologyevents.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 92642 ) and microbiologyevents.spec_type_desc = 'sputum' and microbiologyevents.org_name is not null and strftime('%y-%m',microbiologyevents.charttime) <= '2100-05' order by microbiologyevents.charttime asc limit 1