The relation between the number of some trinucleotides in the sequence of 16S rRNA gene and pathogenicity of bacterial species from the genera of Bacillus and Clostridium was revealed. The species of genus Bacillus, which are pathogenic for humans, mammals and insects, have an increased number of AAA and TAT triplets in 16S rRNA gene. Theoretically, these species, B. anthracis and B. cereus for example, may be detected in the specimen by the higher ratio of AAA plus TAT triplets to the number of GGG triplet. Species of genus Clostridium, which are pathogenic for humans and mammals, have a maximum ratio of AAA and TAT triplet numbers. This ratio was higher than 2.6 for pathogenic species and lower than 2.2 for saprophytic ones. These theoretical data may open a new way for detecting pathogenic bacteria through the determination of triplet numbers in the sequences of 16S rRNA or rRNA. However, the mechanism of evolutionary relation between the number of AAA and TAT triplets in the sequence of 16S rRNA gene and the pathogenicity of bacterial species is not known.
Copyright 2000 Academic Press.