gyrB as a phylogenetic discriminator for members of the Bacillus anthracis– cereus– thuringiensis group

• Published in: Journal of microbiological methods Vol. 56; no. 3; pp. 383 - 394
• Main Authors: La Duc, Myron T, Satomi, Masataka, Agata, Norio, Venkateswaran, Kasthuri
• Format: Journal Article
• Language: English
• Published: Legacy CDMS Elsevier B.V 01-03-2004; Elsevier Science
• Subjects: Bacillus; Bacillus - classification; Bacillus - genetics; Bacillus - pathogenicity; Bacillus anthracis; Bacillus anthracis - classification; Bacillus anthracis - genetics; Bacillus anthracis - pathogenicity; Bacillus cereus; Bacillus cereus - classification; Bacillus cereus - genetics; Bacillus thuringiensis - classification; Bacillus thuringiensis - genetics; Bacillus thuringiensis - pathogenicity; Bacterial Toxins - biosynthesis; Bacterial Typing Techniques - methods; Bacteriological methods and techniques used in bacteriology; Bacteriology; Biological and medical sciences; Discrimination; DNA Gyrase - genetics; DNA, Bacterial - isolation & purification; DNA, Ribosomal - isolation & purification; Enterotoxins - biosynthesis; Fundamental and applied biological sciences. Psychology; Genes, Bacterial; gyrB; Hemolysis; Life Sciences (General); Microbiology; Nucleic Acid Hybridization; Phylogeny; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Sequence Homology; Serotyping; Starch - metabolism; Systematics; Virulence; gyrB; TSB; Discrimination; CFU; TSA; Bacillus; Phylogeny; Bacillus anthracis; Bacillus cereus; Bacillales; Phylogenetic tree; Bacillus thuringiensis; Ribosomal DNA; Bacteria; Bacillaceae
• ISSN: 0167-7012; 1872-8359
• DOI: 10.1016/j.mimet.2003.11.004

Bacillus anthracis, the causative agent of the human disease anthrax,
Bacillus cereus, a food-borne pathogen capable of causing human illness, and
Bacillus thuringiensis, a well-characterized insecticidal toxin producer, all cluster together within a very tight clade (
B. cereus group) phylogenetically and are indistinguishable from one another via 16S rDNA sequence analysis. As new pathogens are continually emerging, it is imperative to devise a system capable of rapidly and accurately differentiating closely related, yet phenotypically distinct species. Although the
gyrB gene has proven useful in discriminating closely related species, its sequence analysis has not yet been validated by DNA:DNA hybridization, the taxonomically accepted “gold standard”. We phylogenetically characterized the
gyrB sequences of various species and serotypes encompassed in the “
B. cereus group,” including lab strains and environmental isolates. Results were compared to those obtained from analyses of phenotypic characteristics, 16S rDNA sequence, DNA:DNA hybridization, and virulence factors. The
gyrB gene proved more highly differential than 16S, while, at the same time, as analytical as costly and laborious DNA:DNA hybridization techniques in differentiating species within the
B. cereus group.