Table 1.
Numbers of putative drug efflux systems encoded in the genomes of reference strains of the B. cereus group, and other Firmicutes.
Fig 1.
Conservation of putative efflux systems encoded in the Bacillus cereus group.
(A) Venn diagram showing conservation of putative efflux systems in fully sequenced representatives of the B. cereus group. (B) Conservation of genes encoding efflux system components in B. cereus ATCC 14579. Reciprocal BLASTP 2.2.28+ searches (as executed through the Proteinortho tool [22]) of the B. cereus ATCC 14579 predicted proteome with 168 other strains in the B. cereus group (S1 Table) were used to determine the level of conservation. Each transporter component is represented by a single box, the size and shading of which corresponds to its conservation. Panel B was generated using TreeMap version 4.1.
Table 2.
Putative B. cereus ATCC 14579 MFS efflux pumps.
Table 3.
Putative B. cereus ATCC 14579 ABC efflux pumps.
Table 4.
Putative B. cereus ATCC 14579 RND efflux pumps.
Table 5.
Putative B. cereus ATCC 14579 SMR efflux pumps.
Table 6.
Putative B. cereus ATCC 14579 MATE efflux pumps.
Fig 2.
Gene expression changes in response to antimicrobial and environmental shock treatments.
Relative efflux pump gene expression levels were examined using qRT-PCR on RNA extracted from B. cereus ATCC 14579 treated with antimicrobial compounds compared with untreated cells. B. cereus ATCC 14579 cells were grown at 30°C in MH broth to OD600 = 0.8 and then treated for 20 minutes with the antimicrobial compounds chloramphenicol, norfloxacin, kanamycin, erythromycin, tetracycline, ethidium bromide, 2,2’-dipyridole, tannic acid and wasp extract, at concentrations corresponding to 50% of the MIC (S3 Table). The BC1744 helicase gene was used as the reference gene to normalize the data. Hierarchical clustering analysis [57] was performed on the average gene expression values using the Pearson correlation method using the TIGR Multi-Experiment Viewer TMEV software [58]. The scale shows log2 fold-changes in gene expression between treated cells and untreated controls.