Numerical identification of bacteria with a hand-held calculator as an alternative to code books

Abstract

The Hewlett-Packard HP 41C hand-held calculator can be used for the numerical identification of bacteria. The dimensions of the identification matrix are limited to about 30 by 22; however, many groups of clinically important bacteria can be numerically identified by this method. Hand-held calculators can be used as an alternative to code books. At present, these calculators and additional tests can help solve identification problems in profiles not contained in code books.

Numerical evaluation of minimal biochemical test combinations for the identification of Enterobacteriaceae species

“…Numerical identification procedures were developed in conjunction with pioneering work in numerical taxonomy (6–8). The methods and procedures described can nowadays be applied quite easily given the availability of microcomputers (10, 17–20). Some constraints on these methods preclude their use in routine work, such as the difficulty of including frequency of occurrence of a given species in certain patient groups or geographical areas.…”

“…Numerical identification was performed according to established principles (6–8, 10, 11) using a software package, IdBact, which is available on the Internet (http://ki.se/labmed/clim/). Percentage positivity in each of the biochemical tests for each species among Enterobacteriaceae was taken from Farmer et al (12).…”