Genetic Diversity of Bacillus thuringiensis from Different Geo-Ecological Regions of Ukraine by Analyzing the 16S rRNA and gyrB Genes and by AP-PCR and saAFLP

Abstract

The Bacillus cereus group consists of closely related species of bacteria and is of interest to researchers due to its importance in industry and medicine. However, it remains difficult to distinguish these bacteria at the intra- and inter-species level. Bacillus thuringiensis (Bt) is a member of the B. cereus group. In this work, we studied the inter-species structure of five entomopathogenic strains and 20 isolates of Bt, which were collected from different geo-ecological regions of Ukraine, using various methods: physiological and biochemical analyses, analysis of the nucleotide sequences of the 16S rRNA and gyrB genes, by AP-PCR (BOX and ERIC), and by saAFLP. The analysis of the 16S rRNA and gyrB genes revealed the existence of six subgroups within theB.cereus group: B anthracis, B. cereus I and II, Bt I and II, and Bt III, and confirmed that these isolates belong to the genus Bacillus. All strains were subdivided into 3 groups. Seventeen strains belong to the group Bt II of commercial, industrial strains. The AP-PCR (BOX and ERIC) and saAFLP results were in good agreement and with the results obtained for the 16S rRNA and gyrB genes. Based on the derived patterns, all strains were reliably combined into 5 groups. Interestingly, a specific pattern was revealed by the saAFLP analysis for the industrial strain Bt 0376 р.о., which is used to produce the entomopathogenic preparation “STAR-t”.

Reliable Identification of Bacillus cereus Group Species Using Low Mass Biomarkers by MALDI-TOF MS

“…Moreover, errors in conventional identification methods may lead to discordant results of MALDI-TOF MS identification [3]. Due to the high genetic and phenotypic similarity between B. thuringiensis and B. cereus [31,43], they might represent the same species [30], thus could not be distinguished based on sequencing alone [44]. For these reasons, we paid special attention to the verification of 22 strains to ensure specific biomarkers for reliable identification of B. cereus and B. thuringiensis.…”

“…For example, B. anthracis is non-motile, non-hemolytic, and non-penicillin resistant, which distinguishes it from B. cereus, B. thuringiensis, and B. mycoides [28]. Both B. cereus and B. thuringiensis are motile; however, B. thuringiensis can be distinguished from B. cereus based on its ability to produce the Bt toxin [29][30][31]. However, it is known that phenotypic tests and sequence analysis of the 16S rRNA genes could fail to differentiate between members of the B. cereus group [32].…”

Characterization of lepidopteran-specific cry1 and cry2 gene harbouring native Bacillus thuringiensis isolates toxic against Helicoverpa armigera

“…16S rRNA gene sequencing is a routine method used for the taxonomic identification of bacteria [35] . However, the method has not been successful in clearly distinguishing the members of the B. cereus group of which B. thuringiensis is one of the member [35] . So, the partial 16S rRNA gene sequences were considered B. thuringiensis for the statistical counting if they showed maximum similarity to either B. thuringiensis or B. cereus .…”

Evaluación in vitro de la formación de biopelículas de bacterias marinas del Caribe colombiano

“…The nearby strains were used for maximum likelihood phylogenetic analyses. However, the use of other markers such as gyrB and XRE is recommended (Helgason et al, 2000;Punina et al, 2013;Wei et al, 2019) to identify all strains up to the species taxonomic level (Helgason et al, 2000;Punina et al, 2013;Wei et al, 2019).…”