Coherent fluctuation nephelometry in clinical microbiology

Abstract

In this article data concerning coherent fluctuation nephelometry (CFN) use in clinical microbiology is presented. CFN-analyzer allows to solve two important problems – fast urine screening for bacteriuria within 2-4 hours and antibiotic susceptibility testing within 3-6 hours. Altogether more than 650 urine samples were tested, and the effectivity of CFN-analyzer for preliminary selection of samples for further analysis was shown. Method allows to detect negative samples, reducing the number of urine analyses by 70-80%. Simultaneous analysis of growth curves and concentration of microorganisms shows high sensitivity and specificity (95.2% и 96.9%). Also more than 250 antibiotic susceptibility tests were performed using CFN-analyzer to show its effectiveness for determination of resistant properties of both pure cultures and urine microflora without isolation of bacteria. The agreement with traditional methods was from 84% to 88%. The use of CFN-analyzer with express methods of identification of microorganisms (chromogenic nutrient broths or mass-spectrometry) allows to make full urine analysis within 1-2 days. In the future CFN-analyzer gives an opportunity to screen different human biological liquids, and finds an application for other microbiological tasks, including standardization and speeding-up in sanitary bacteriology.