Computerised biochemical fingerprinting a new tool for typing of bacteria

Abstract

Summary Typing of bacteria below the species level is important for many epidemiological, nosocomial and ecological investigations. Desired properties of a good typing system include high reproducibility, high stability, good discriminatory power and typability. Furthermore, the practical performance should be simple and easy to learn. Reagents and equipment needed should also be easily available and relatively inexpensive. Biochemical fingerprinting is a typing method based on quantitative measurements of the kinetics of biochemical reactions of bacteria. In this review a computerised typing system based upon numerical analysis of biochemical fingerprints of bacteria (the PhenePlate (PhP) system) is described. The test is performed in pre-prepared 96-well microtitre plates containing dehydrated reagents, carefully selected to yield a high discrimination within the studied group of bacteria. The test results are automatically read by a microplate reader, which also stores data and performs all calculations and finally prints a dendrogram and a list of biochemical phenotypes (BPTs). The method is evaluated and compared with other typing methods according to the above criteria, and application examples in the fields of nosocomial infections, epidemiology and microbial ecology are given. Special attention is given to the possibility of investigating large numbers (200–500 per day) of isolates, making it possible to study the composition of complex bacterial populations.