Novel inducible filamentous sliding motility identified in pathogenic Bacillus cereus group species
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ABSTRACT:
PROVIDER: PRJNA563896 | ENA |
REPOSITORIES: ENA
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Project description:We isolated an atmospheric contaminant, subsequently identified as a new strain of Bacillus mobilis, which showed a novel, robust, inducible filamentous sliding motility and completely colonized a bacterial culture plate in less than 48 h under some conditions. This flagella-independent sliding motility was characterized by long filamentous cells at the expanding edge, and was induced when cells were inoculated onto lawns of metabolically inactive Campylobacter jejuni cells, heat killed bacterial biomass, and milk or blood dried onto agar plates. Phosphatidylcholine (PC), bacterial membrane components, and sterile human fecal extracts were sufficient to induce filamentous expansion. Screening of eight other Bacillus spp. (five from the B. cereus group and three other Bacillus spp.) showed that filamentous motility was conserved amongst B. cereus group species to varying degrees. RNAseq of filamentously expanding cells collected from PC and milk lawn plates in comparison to rod-shaped cells from control plates revealed that genes related to metabolism, ion and amino acid transport were differently regulated, genes controlling sporulation were reduced, and some virulence genes (e.g., hblA/B/C/D and plcR) were increased. We hypothesize that the robust and conserved nature of filamentous motility in pathogenic B. cereus group species can enhance bacterial colonization during host colonization.
2020-01-01 | GSE136873 | GEO
Project description:Active migration across semi-solid surfaces is important for bacterial success by facilitating colonization of unoccupied niches and is often associated with altered virulence and antibiotic resistance profiles. We isolated an atmospheric contaminant, subsequently identified as a new strain of Bacillus mobilis, which showed a unique, robust, rapid, and inducible filamentous surface motility. This flagella-independent migration was characterized by formation of elongated cells at the expanding edge and was induced when cells were inoculated onto lawns of metabolically inactive Campylobacter jejuni cells, autoclaved bacterial biomass, adsorbed milk, and adsorbed blood atop hard agar plates. Phosphatidylcholine (PC), bacterial membrane components, and sterile human fecal extracts were also sufficient to induce filamentous expansion. Screening of eight other Bacillus spp. showed that filamentous motility was conserved amongst B. cereus group species to varying degrees. RNA-Seq of elongated expanding cells collected from adsorbed milk and PC lawns versus control rod-shaped cells revealed dysregulation of genes involved in metabolism and membrane transport, sporulation, quorum sensing, antibiotic synthesis, and virulence (e.g., hblA/B/C/D and plcR). These findings characterize the robustness and ecological significance of filamentous surface motility in B. cereus group species and lay the foundation for understanding the biological role it may play during environment and host colonization.
| S-EPMC7784679 | biostudies-literature
Project description:Transcriptome comparison of Bacillus subtilis Natto under sliding permissive (0.7% agar) and restrictive (1.5% agar or spo0A mutant strain) conditions.
2015-08-04 | GSE43840 | GEO
Project description:Wild-type diploid cells were shifted from yeast-form growth in SHAD liquid (plentiful glucose and ammonium) to filamentous-form growth on SLAD agar (low ammonium). Samples of filamentous-form cells were collected hourly for 10 hours. Filamentous-form and yeast-form exponential-phase targets were co-hybridized. Keywords: time-course
2004-02-02 | GSE679 | GEO
Project description:While some members of the Bacillus cereus group constitutively display filamentous growth, other members of this group may grow filamentously as a result of environmental stimuli or genetic changes. In this study, two variants of B. cereus ATCC 14579 displaying filamentous growth during exponential phase were compared with a variant which grew as single cells or short chains during this stage of growth. Phenotypic differences between the variants were investigated by a range of methods, comparing the variants at the genomic, transcriptional and translational level to search for changes which could explain the observed phenotypes. Differences were found between filamentous and purely planktonic variants as well as between the filamentous variants. Filamentous variants displayed rougher colony morphology on agar plates, and did not lyse after death or sporulation. One filamentous variant additionally showed reduced sporulation and increased transcription of class I and and III heat shock proteins, but these phenotypes were not found in the other filamentous variant.
2010-07-01 | E-TABM-924 | biostudies-arrayexpress
Project description:Bacillus cereus is the second leading cause of collective food poisoning in France. B. cereus is also associated with severe clinical infections leading to patient death in 10% of the cases. The emergence of B. cereus as a foodborne and opportunistic pathogen has intensified the need to distinguish strains of public health concern. In this work, by performing a screen on a large collection of B. cereus strains of varying pathogenic potential, we identified genetic determinants capable of discriminating B. cereus strains inducing negative clinical outcomes. The combination of 4 biomarkers is sufficient to accurately discern clinical strains from harmless strains. Three of the biomarkers are located on the chromosome, with a fourth one identifying a plasmid carried by most pathogenic strains. A 50 kbp region of this plasmid promotes the virulence potential of these strains and could thus be defined as a new pathogenicity island of B. cereus. These new findings help in the understanding of B. cereus pathogenic potential and complexity and may provide tools for a better assessment of the risks associated with B. cereus contamination to improve patient health and food safety.
2022-01-12 | GSE171128 | GEO
Project description:Transcriptome comparison of Bacillus subtilis Natto under sliding permissive (0.7% agar) and restrictive (1.5% agar or spo0A mutant strain) conditions. B subtilis Natto wild type cells were grown on the top of LB solid medium with 1.5% and 0.7% agar concentration (samples 1-4). B subtilis Natto wild type and spo0A derivative were grown on top of LB solid medium with 0.7% agar concentration (Sample 5-7). In first experiment, 4 biological replicates were used, while in the second experiment 3 biological replicates included. Dye swaps are included in both experiments.
2015-08-04 | E-GEOD-43840 | biostudies-arrayexpress
Project description:Long-range gene regulation is rare in bacteria and is confined to the classical DNA looping model. Here, we use a combination of biophysical approaches, including X-ray crystallography and single-molecule analysis, to show that long-range gene silencing on the plasmid RK2, a source of multidrug resistance across diverse Gram-negative bacteria, is achieved cooperatively by a DNA-sliding clamp, KorB, and a clamp-locking protein, KorA. We find that KorB is a CTPase clamp that can entrap and slide along DNA to reach distal target promoters. We resolved the tripartite crystal structure of a KorB-KorA-DNA co-complex, revealing that KorA latches KorB into a closed-clamp state. KorA thus stimulates repression by stalling KorB sliding at target promoters to occlude RNA polymerase holoenzymes. Altogether, our findings explain the mechanistic basis for KorB role-switching from a DNA-sliding clamp to a co-repressor, and provide a new paradigm for the long-range regulation of gene expression.
2024-09-01 | GSE274567 | GEO
Project description:STUDY QUESTION: What are the causative genetic variants in patients with male infertility due to severe sperm motility disorders?
SUMMARY ANSWER: We identified high confidence disease-causing variants in multiple genes previously associated with severe sperm motility disorders in 9 out of 21 patients (43%). We also identified variants in novel candidate genes in 8 additional patients (38%).
WHAT IS KNOWN ALREADY: Severe sperm motility disorders are a form of male infertility characterised by vital, but immotile sperm often in combination with a spectrum of structural abnormalities of the sperm flagellum. Examples of this spectrum of disorders include dysplasia of the fibrous sheath / multiple morphological abnormalities of the sperm flagella (DFS-MMAF) and severe forms of asthenozoospermia associated to non-specific structural defects. These disorders frequently recur in families and may include chronic respiratory disease. As such, genetic causes are suspected and many genes have recently been reported. Currently, depending on the clinical sub-categorisation, up to 50% of causality in patients with severe sperm motility disorders can be explained by pathogenic variants in at least 21 known genes.
STUDY DESIGN, SIZE, DURATION: We performed exome sequencing in patients with severe sperm motility disorders from two different clinics, aiming to identify the underlying genetic defects and establishing a diagnostic yield in both.
PARTICIPANTS/MATERIALS, SETTING, METHOD: Two groups of infertile men, one from Argentina (n= 9) and one from Australia (n=12), with clinically defined sperm motility disorders were included. All patients in the Argentine cohort were diagnosed with DFS-MMAF, based on transmission electron microscopy. Exome sequencing was performed in all 21 patients and variants with an allele frequency of <1% in the gnomAD population were prioritised and interpreted.
MAIN RESULTS AND ROLE OF CHANCE: In 9/21 patients (43%), we identified pathogenic variants in known sperm motility disorder genes: CFAP43 (3 patients); CFAP44 (2 patients), QRICH2 (2 patients), DNAH1 (1 patient) and DNAH6 (1 patient). The diagnostic rate did not differ markedly between the Argentinian and the Australian cohort (44% and 42%, respectively). Furthermore, we identified patients with variants in the novel candidate sperm motility genes CFAP58, DNAH12, DRC1, MDC1, PACRG, SSPL2C and TPTE2. One patient presented with two possibly damaging variants in four candidate genes and it remains unclear which variants were responsible for the severe sperm motility defect in this patient.
LIMITATIONS, REASONS FOR CAUTION: In this study, we described patients with potential bi-allelic variants in known and novel candidate genes for severe sperm motility disorders. Due to unavailability of parental DNA, we have not assessed de novo or maternally inherited dominant variants and could not phase the mutations to establish in all cases that the mutations occur on both alleles.
WIDER IMPLICATIONS OF THE FINDINGS: Our results confirm an important role for five known genes for sperm motility and we demonstrate that exome sequencing is an effective method to diagnose patients with severe sperm motility defects (9/21 diagnosed; 43%). Furthermore, our analysis revealed seven novel candidate genes for severe sperm motility disorders. Genome-wide sequencing of additional patient cohorts and re-analysis of exome data of currently unsolved cases may reveal additional variants in these novel candidate genes.
| EGAS00001005018 | EGA