Efficacy of an enzyme-linked immunosorbent assay for detection of urinary tract immunoglobulins for diagnosis of urinary tract infections

Abstract

Results of the Uristat test (Shield Diagnostics Ltd.), a novel enzyme-linked immunosorbent assay (ELISA) for detection of urine antibodies to seven common bacterial pathogens, were compared with results of urine culture, urinalysis, and clinical history to determine the usefulness of Uristat in the diagnosis of urinary tract infections (UTIs). Midstream, catheterized, and indwelling catheter urine specimens sent to the laboratory for culture were included in the study. Quantitative cultures were performed on both 5% sheep blood agar and eosin-methylene blue agar. Uristat ELISAs were performed according to the manufacturer's instructions. By using a Bacillus subtilis bioassay technique, antibacterial activity was detected in the urine of 236 (22.2%) of 1,061 patients. Probable, possible, or asymptomatic UTIs were diagnosed for 258 (24.3%) of the 1,061 patients. Of those infections, 219 (84.9%o) were caused by bacterial species whose antibodies were detectable by Uristat. Uristat's sensitivity and specificity were 76.7 and 56.0%o, respectively. Uristat's predictive values of positive and negative results were 31.2 and 90.2%, respectively. Further development of the Uristat test is necessary before it can be of assistance in the diagnosis of UTIs.on July 6, 2020 by guest

A review on urinary tract infections diagnostic methods: Laboratory-based and point-of-care approaches

“…The Enzyme-Linked Immunosorbent Assay (ELISA) is a biochemical assay that use antibodies and enzyme-mediated color change to detect the presence of antigens, antibodies and proteins in a sample [23]. This method is used in different diagnoses and is also the base of the urinary Uristal test (Shield Diagnostics Ltd.) to detect antibodies specific for antigens of common pathogens [23,24]. However, ELISA assays have been reported as not sufficiently sensitive and specific to be used in urine routine diagnoses [24,25].…”

“…This method is used in different diagnoses and is also the base of the urinary Uristal test (Shield Diagnostics Ltd.) to detect antibodies specific for antigens of common pathogens [23,24]. However, ELISA assays have been reported as not sufficiently sensitive and specific to be used in urine routine diagnoses [24,25].…”

Non-antibiotic compounds affecting the growth of urinary pathogens during urine culture: a preliminary in vitro study

“…Detection of inhibitory activity among the tested compounds was performed on MHA plates, containing B. subtilis ATCC 6633 spores [22,24,25]. A maximum of 6 sterile filter paper discs (impregnated with 10 µL of the solutions of the solutions of different the tested compounds) were placed on MHA, containing a B. subtilis spore suspension (250 µl per 1 liters).…”

“…The inhibitory activity of the tested compounds was assessed semi-quantitatively; the zone of inhibition around the disks impregnated with the solu-tions of the tested compounds were recorded after 16-18 h of incubation, using a caliper (expressed as milimeters ± standard deviation [SD]). Any measureable zone of inhibition was considered as positive [22,24,25]. DMSO (at 2 V/V% concentration) was used as a negative control for the tested compounds, while ciprofloxacin, meropenem and trimethoprim/sulfamethoxazole disks were used as positive controls.…”