Rapid screening for significant bacteriuria using a Coulter Counter.

Abstract

(Hoeprich, 1960) and dip-slides (Mackey and Sandys, 1965) are used. Recently, the estimation of bacterial adenosine 5'-triphosphate (ATP) in urine by instrumental analysis (Alexander et al., 1976;Johnston et al., 1976) has added a new approach to the detection of significant bacteriuria, due to the speed with which results can be obtained.This paper describes a study in which the Coulter Counter was tested to determine its suitability for the rapid screening of urines for significant bacteriuria. Material and methods CULTURE METHODA total of 956 urine specimens, mainly from male and female inpatients, were studied. The specimens were those received in a diagnostic bacteriological service and were stored at 4'C before examination by "Present address: Laboratory of the Government Chemist,

Analysis of the disagreement between automated bioluminescence-based and culture methods for detecting significant bacteriuria, with proposals for standardizing evaluations of bacteriuria detection methods

“…The samples positive by the pour plate method and negative by the automated test were, in large part, also negative by the standard loop method. This is also demonstrated in Table 1; when those urine samples for which standard loop and pour plate results differed were excluded from the analysis, then the false-negative rate of the automated test decreased substantially, from 25 to 9%.…”

“…This has led to the use of a variety of different reference methods for detecting bacteriuria, for example, pour plate quantitative colony counts (27), "Droplette" quantitative colony counts (4a, 8), surface quantitative colony counts (11), semiquantitative standard loop colony counts (1, 2, 4a, 7, 8, 10, 12, 17, 20), filter paper strip methods (4a, 25), and a spiral plating method (24a). Moreover, these quantitative or semiquantitative procedures have been defined as positive on the basis of different colony count criteria: 1 x 105 colony-forming units (CFU)/ml (1,7,8,10,12,20,23,27), 7 x 104 CFU/ml (11), or different counts depending on qualitative factors such as the identity of the organism(s) grown or the presence or absence of leukocytes (2, [24][25]. It is thus extremely difficult to compare the results of one rapid or automated method with another.…”

Clinical laboratory evaluation of a urine screening device

“…Many of these techniques can be automated, although the cost of the instruments and consumable supplies can be high. Growth-independent techniques include biochemical tests such as the nitrite or glucose tests (7,15), leukocyte esterase determination (17), detection of endotoxin (10), measurement of bacterial ATP (5), quantitation of bacteria with a particle counter (20), and microscopic examination of urine for the presence of bacteria (10,12,14) or pyuria (6,19,22) or both. The results of these techniques can be obtained much faster in comparison with the growth-dependent tests.…”

Limit of Resolution of Flow Cytometry for the Detection of Selected Bacterial Species

“…To date, there have been few published reports on the use of flow cytometry to quantitate specific bacterial species in (Smither, 1977;Dow et al, 1979;Alexander et al, 1981;Baker et al, 1983) have been directed toward the qualitative detection of specific micro-organisms. Our finding that light-scatter counting efficiency is quite low (Table 3) is in accord with the results of Kornman et al (1984), Barnett et al (1984), and Phillips and Martin (1988).…”