Dataset Information

Ribosomal background of the Bacillus cereus group thermotypes.

ABSTRACT: In this study we reconstructed the architecture of Bacillus cereus sensu lato population based on ribosomal proteins, and identified a link between the ribosomal proteins' variants and thermal groups (thermotypes) of the bacilli. The in silico phyloproteomic analysis of 55 ribosomal proteins (34 large and 21 small subunit r-proteins) of 421 strains, representing 14 well-established or plausible B. cereus sensu lato species, revealed several ribosomal clusters (r-clusters), which in general were well correlated with the strains' affiliation to phylogenetic/thermal groups I-VII. However, a conformity and possibly a thermal characteristic of certain phylogenetic groups, e.g. the group IV, were not supported by a distribution of the corresponding r-clusters, and consequently neither by the analysis of cold-shock proteins (CSPs) nor by a content of heat shock proteins (HSPs). Furthermore, a preference for isoleucine and serine over valine and alanine in r-proteins along with a lack of HSP16.4 were recognized in non-mesophilic thermotypes. In conclusion, we suggest that the observed divergence in ribosomal proteins may be connected with an adaptation of B. cereus sensu lato members to various thermal niches.

SUBMITTER: Fiedoruk K

PROVIDER: S-EPMC5390287 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:The Bacillus cereus group comprises 18 different species, including human pathogens as well as psychrotolerant strains that are an important cause of fluid milk spoilage. To enhance our understanding of the genetic markers associated with psychrotolerance (defined here as > 1 log10 increase in cfu/mL after 21 days incubation at 6°C) among dairy-associated B. cereus group isolates, we used genetic (whole genome sequencing) and phenotypic methods [growth in Skim Milk Broth (SMB) and Brain Heart Infusion (BHI) broth] to characterize 23 genetically-distinct representative isolates from a collection of 503 dairy-associated isolates. Quality threshold clustering identified three categories of psychrotolerance: (i) 14 isolates that were not psychrotolerant in BHI or SMB, (ii) 6 isolates that were psychrotolerant in BHI but not in SMB, and (iii) 2 isolates that were psychrotolerant in BHI and SMB. One isolate, which was psychrotolerant in BHI broth but was just below the cut-off of >1 log10 cfu/mL increase in SMB was not assigned to a cluster. A maximum likelihood phylogeny constructed with core genome single nucleotide polymorphisms classified all psychrotolerant isolates (i.e., psychrotolerant in BHI) into clade VI (representing B. mycoides/weihenstephanensis). Analysis of correlations between gene ortholog presence or absence patterns and psychrotolerance identified 206 orthologous gene clusters that were significantly overrepresented among psychrotolerant strains, including two clusters of cold shock proteins, which were identified in 8/9 and 7/9 psychrotolerant isolates. Gene ontology analyses revealed 36 gene ontology terms that were overrepresented in psychrotolerant isolates, including putrescine catabolic processes and putrescine transmembrane transporter activity. Lastly, Hidden Markov Model searches identified three protein family motifs, including cold shock domain proteins and fatty acid hydroxylases that were significantly associated with psychrotolerance in BHI broth. Analyses of CspA sequences revealed a positive association between psychrotolerant strains and a previously identified "psychrotolerant" CspA sequence. Overall, our data highlight genetic and phenotypic differences in psychrotolerance among B. cereus group dairy-associated isolates and show that psychrotolerance is dependent on the growth medium. We also identified a number of gene targets that could be used for specific detection or control of psychrotolerant B. cereus group isolates.

Dataset Information

Ribosomal background of the Bacillus cereus group thermotypes.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets