Measurement of urinary lipopolysaccharide antibodies by ELISA as a screen for urinary tract infection.

Abstract

Five hundred and twenty two clinical urine specimens submitted for routine microbiological examination were tested in parallel by conventional microscopy and culture and for lipopolysaccharide antibodies by an enzyme linked immunoabsorbent assay (ELISA) to assess the ELISA as a screen for urinary tract infection. When the ELISA alone was compared with routine methods the specificity sensitivity, and predictive value of positive and negative tests was 73-2%, 75 7%, 51-1% and 38-5%. For ELISA with microscopy the same variables were 71-1%, 82-2%, and 92-4% and 94 7%, respectively. The ELISA absorbency increased with increasing bacterial numbers, but results varied widely. Only 65-4% of urines which contained > 105 bacterial/ml were positive by ELISA; 36-8% of urines with < 103 bacterialml were positive by ELISA; 100% of > 105 bacteria/ml cultures of Pseudomonas sp (n = 4), Staphylococcus aureus (n = 3), and Streptococcus faecalis (n = 2) were positive by ELISA but only 71-4% of Proteus sp (n = 7), 61-4% coliforms (n = 70), and 25% of coagulase negative staphylococci (n = 4).It is concluded that further development is required before the ELISA can be used for routine screening for urinary tract infection.

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

“…The Uristat assay also cannot detect antibodies to Chlamydia trachomatis, another significant uropathogen (6), or to additional pathogens including Mycoplasma species, Corynebacterium species, and anaerobes (which are rarely uropathogens) (33,45). The results of the current study, showing low Uristat sensitivity and specificity, are similar to those of a previous report of another commercially available ELISA system for detection of urinary tract antibodies (20).…”

“…Falsely negative results of the Uristat test could be expected to occur because of many factors other than test insensitivity. These factors include decreased synthesis or increased degradation of antibodies in some patients (4,20,28,34), variations in water diuresis (4,21), antibiotic therapy (28), low levels of antibodies in infants younger than 1 year of age (1,4,8,12), and the presence of either bacteria (1,8) or soluble bacterial antigen (31) in the urine, resulting in absorption and a reduction in free detectable antibodies. Falsely positive Uristat results might also be expected for reasons other than lack of test specificity.…”

Urinary IgG antibody against mixed heat-killed coliform antigen and lipopolysaccharide core antigen.

“…Other workers have found that measuring lipopolysaccharide antibodies in urine is not a useful way of screening urine samples before culture. 6 It is clear that urinary antibodies can be measured in association with symptoms sug-gestive of urinary tract infection. It may be possible to define particular classes or specificities of urinary antibody which are of predictive value in the diagnosis of urinary tract infection.…”

Identifying Bacteria in Human Urine: Current Practice and the Potential for Rapid, Near-Patient Diagnosis by Sensing Volatile Organic Compounds

“…A negative test result provides valuable clinical information and may eliminate the need for quantitative culture (39). These enzymatic urine screening tests have not yet been utilised as an efficient tool for diagnosis of UTI since they have not exhibited results superior to those of methods regarded previously (41). This method is based on the chemical detection of nitrites, because most bacteria (e.g.…”

“…No further development of the method has been reported for the detection of UTI, probably due to its lack of sensitivity (41). No further development of the method has been reported for the detection of UTI, probably due to its lack of sensitivity (41).…”