what specimen tests did patient 13897 undergo for the last time until 11/2101?
select microbiologyevents.spec_type_desc from microbiologyevents where microbiologyevents.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 13897 ) and strftime('%y-%m',microbiologyevents.charttime) <= '2101-11' order by microbiologyevents.charttime desc limit 1