In recent years, methods based on DNA analysis have been developed for rapid detection and identification of bacteria. Analysis of 16S rRNA gene sequence (1483e1489 bp) is the most commonly used method for the identification of bacteria and for elucidating bacterial phylogenetic relationships. However, due to high genetic homology inside certain bacterial genera, the 16S rRNA may not be especially useful for the discrimination of closely-related species this being the case of some Bacillus spp. such as the B. cereus and B. subtilis groups.