Lack of precision in commercial identification systems: correction using Bayesian analysis.

Commercial microbial identification systems rank the relative likelihood of species identity on the basis of in vitro reactions only. Failure to consider the prevalence of individual taxa results in a spurious demotion of common species; and a tendency toward over reporting of rare microbes. The incorporation of Bayesian analysis into identification matrices can provide for a realistic ranking of bacterial species which fulfil given biocode schemes.