False-positive Chlamydiazyme results during urine sediment analysis due to bacterial urinary tract infections.
Our study examined whether urinary tract infections (UTIs) would cause false-positive results when urine sediment was tested with the Chlamydiazyme (CZ) system. Thirty-six infected urine samples and fifteen controls were studied. All controls were negative. Forty-seven percent of Escherichia coli UTIs (n = 30) and 100% of Klebsiella pneumoniae UTIs (n = 4) were positive on CZ testing of urine sediment. Nine E. coli UTIs positive by CZ were negative by direct fluorescent-antibody staining. When suspensions of the pure cultures were analyzed, 47% of E. coli and 100% of K. pneumoniae samples were CZ positive. False-positive results were not related to organism biotype or urine characteristics, including pH, specific gravity, and leukocyte count. We conclude that the presence of a UTI and also bacterial contamination must be ruled out prior to urine sediment testing.
Demaio
J
J
27th Medical Group (TAC), Cannon Air Force Base, New Mexico 88103.
Boyd
R S
RS
Rensi
R
R
Clark
A
A
D000942:Antigens, Bacterial / Q000652:urine; D001431:Bacteriological Techniques; D002690:Chlamydia Infections / Q000175:diagnosis* / Q000652:urine; D002692:Chlamydia trachomatis; D003429:Cross Reactions; D005069:Evaluation Studies as Topic; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008297:Male; D014552:Urinary Tract Infections / Q000175:diagnosis* / Q000652:urine
D000942:Antigens, Bacterial