Automated bacteriuria screening using the Berthold LB 950 luminescence analyser

Area of Science:

• Clinical Microbiology
• Biochemistry

Background:

• Bacteriuria diagnosis traditionally relies on urine culture, which is time-consuming.
• Rapid and automated methods are needed for efficient screening of bacterial infections in urine.

Purpose of the Study:

• To evaluate the performance of an automated luminescence analyzer for estimating bacterial adenosine triphosphate (ATP) in urine.
• To assess the utility of this automated method as a rapid screening test for bacteriuria.

Main Methods:

• The Berthold LB950 Automatic Luminescence Analyser was used to measure bacterial ATP in 1040 urine samples.
• Bioluminescence results were compared against two reference culture methods (pour plate and standard loop).
• Frequency distributions of bacterial counts and ATP levels were analyzed.

Main Results:

• The automated test provided results within 15 minutes, detecting bacteriuria at the 10^5 CFU/ml level.
• Specificities ranged from 79% to 98% (when contaminated urines were excluded).
• Sensitivities were 84% (pour plate) and 91% (standard loop), improving to 98% with uncontaminated samples.

Conclusions:

• The automated bioluminescence assay is a rapid and effective screening tool for bacteriuria.
• The method demonstrates good sensitivity and specificity, particularly for high-quality urine specimens.
• While the automated test is expensive, it offers significant time advantages over traditional culture methods.