Clinical evaluation of the slide centrifuge (cytospin) gram's stained smear for the detection of bacteriuria and comparison with the FiltraCheck-UTI and UTIscreen

Abstract

The cytospin Gram's stained smear method for the detection of bacteriuria was compared with the FiltraCheck-UTI, the UTIscreen and culture of urine specimens from adult male and female inpatients and outpatients in a tertiary care medical institution. At a level of > or = 10(5) CFU/mL, the sensitivity of all three methods was at least 93% for organisms identified as potential pathogens. Investigation of false-negative screening tests by chart review demonstrated that only 5 of 10 combined misses in this category were clinically significant. At a level of > or = 10(4) CFU/mL, the sensitivity of the cytospin method remained essentially unchanged, whereas that of the FiltraCheck-UTI and the UTIscreen decreased to 89% and 85%, respectively. False positives were most frequent with the FiltraCheck-UTI, which was due in part to the presence of white blood cells in the urine. All three tests performed well in this population of patients.