Automated methods for detection of bacteriuria.

Urine specimens represent a large portion of cultures received by the clinical microbiology laboratory. Much time and effort are spent screening these specimens and approximately 80 percent show no growth. The methods employed for detection of bacteriuria include microscopic, chemical, culture, and automated. The most widely used procedure has been an agar plate culture method. However, this method requires overnight incubation and therefore results are delayed. Within the last decade many automated methods have been introduced for detecting bacteriuria, and results are available more rapidly than with the agar plate culture method. In addition to decreased detection time, these systems are accurate and cost-effective. The purpose of this report is to review these automated bacteriuria screening systems, which include bioluminescence, colorimetry, electrochemical screening, electrical impedance, microcalorimetry, photometry, and radiometry. Accuracy, detection time, and cost are also discussed in this review.