One has done two times of urine culture test. The first time it shows E-coli >=10,000 cfu/ml and one of antibiotic Ampicillin is Resistant >=32. A few years late the second time of urine culture does not show E-Coli but Enterococcus 1,000 – 10,000 cfu/ml and the same antibiotics Ampicillin changes to Sensitive <= 2.
Why does two urine culture show different bacteria? Is it due to only one bacteria is detectable while others do not exist in a given urine culture test or it is due to the lab checks only ONE specific bacteria? Thank you for your answer.