Project description:Purpose:To uncover the related mechanisms underlie virulence attenuation of Brucella canis MucR mutant strain. Methods:Three Brucella canis RM6/66 strains and three Brucella canis ΔmucR strains were grown in TSB at 37℃ until the log phase was reached, total RNA was isolated using the TRIzol according to the manufacturer’s instructions.The sequencing library of each RNA sample was prepared by using NEB Next Ultra Directional RNA Library Prep Kit for Illumina as recommended by the manufacturer. An Illumina platform was used to perform the transcriptome sequencing. Results: The results revealed that expressions of 694 genes were significantly different between RM6/66 and ΔmucR. Data analysis showed that in the COG term, the different expressed genes involved in translation, ribosomal structure and biogenesis, signal transduction mechanisms, energy production and conversion, intracellular trafficking, secretion, and vesicular transport, and extracellular structures were significantly affected. Pathway enrichment analysis indicated that the genes involved in ribosome, oxidative phosphorylation, aminoacyl-tRNA biosynthesis and protein export were significantly enriched.
Project description:Investigation of whole genome gene expression level changes in a B. suis 1330 regA mutant, compared to the wild-type strain. The two-component system RegBA of Brucella suis plays a central role in the control of respiratory systems adapted to oxygen deficiency. The mutant strain is affected in long-term persistence in vitro (this study) and in chronic infection in vivo (Abdou, E et al. 2013, Infect.Immun. 81: 2053-61). Using an original “in vitro model of persistence”, we compare large-scale transcriptome of the wild-type and ∆regA strains to identify the RegA-regulon potentially involved in the set-up of the persistence state.
Project description:To explore the role of Brucella BI-1 in Brucella suis S2, we constructed the Brucella BI-1 deletion mutant strain and its complementary strain. We then determined the effect of Brucella BI-1 deletion on the physiological characteristics of Brucella suis S2 and revealed them via integrated transcriptomic and proteomic analyses. Brucella BI-1 deletion altered the membrane properties of Brucella suis S2 and decreased its resistance to acidic pH, H2O2, polymyxin B, and lincomycin. Additionally, deleting Brucella BI-1 led to defective growth, cell division, and viability in Brucella suis S2. In conclusion, our results revealed that Brucella BI-1 is a bacterial cytoprotective protein involved in membrane homeostasis, cell division, and stress resistance in Brucella suis S2.
Project description:MucR is one of the few transcriptional regulatory proteins that has been linked to Brucella pathogenesis. We used custom-made Affymetrix B. abortus strain 2308 derived GeneChips to copare the gene expression properties of wild type and isogenic mucR mutant cells.
Project description:Investigation of whole genome gene expression level changes in a Brucella melitensis delta prlr mutant compared to the wild type strain. The mutants analyzed in this study are further described in A. Mirabella, R-M Yanez, R.M. Delrue, S. Uzureau, M.S. Zygmunt, A. Cloeckaert, X. De Bolle, J.J. Letesson (2012). The two component system PrlS/PrlR of Brucella melitensis is required for persistence in mice and appears to respond to ionic strength. Microbiology
Project description:Lytic bacteriophages able to infect and kill Dickeya spp. can be readily isolated from virtually all Dickeya spp.-containing environments, yet little is known about the selective pressure those viruses exert on their hosts. Here, we identified two spontaneous phage-resistant D. solani IPO 2222 mutants, DsR34 and DsR207, resistant to infection caused by phage vB_Dsol_D5 (ΦD5) that expressed a reduced ability to macerate potato tuber tissues compared to the wild-type, phage-susceptible D. solani IPO 2222 strain. Genome sequencing revealed that mutants had point mutations in two genes encoding: secretion protein HlyD (mutant DsR34) and elongation factor Tu (EF-Tu) (mutant DsR207). Both mutations impacted the proteoms of D. solani grown in rich and minimal media. Furthermore, DsR34 and DsR207 were characterized for features essential for their ecological success in a plant environment, including the ability to use various carbon and nitrogen sources, production of plant cell wall degrading enzymes, ability to form biofilms, siderophore production, swimming and swarming motility and virulence in planta. Compared to the wild-type ΦD5-susceptible D. solani strain, mutants DsR34 and DsR207 expressed reduced ability to macerate chicory leaves and to colonize and cause symptoms in growing potato plants. The implications of the ΦD5 resistance on the ecological performance of D. solani are discussed.
Project description:Staphylococcus aureus (S. aureus) is a known pathogen able to infect humans and animals. Human S. aureus isolates are often associated with carriage of Sa3int prophages combined with loss of beta-hemolysin production due to gene disruption, whereas animal isolates are positive for beta-hemolysin associated with absence of Sa3int prophages. Sa3int prophages are known to contribute to staphylococcal fitness and virulence in human host by providing human-specific virulence factors encoded on the prophage genome. Strain-specific differences in regard to phage transfer, lysogenization and induction are attributable to yet unknown staphylococcal factors specifically influencing prophage gene expression. In this work we used tagRNA-sequencing approach to specifically search for these unknown host factors and differences in prophage gene expression. For this purpose, we established a workflow revealing the first direct comparison for differential gene expression analysis on two distinct single-lysogenic S. aureus isolates. Further, global gene expression patterns were investigated in two S. aureus isolates upon mitomycin C treatment and compared to uninduced conditions. This provides new insights into the tightly linked host-phage interaction network.
Project description:This SuperSeries is composed of the following subset Series: GSE35612: Microarray analysis of gene expression in rams experimentally infected with a rough virulent strain of Brucella ovis (acute phase) GSE35613: Microarray analysis of gene expression in rams experimentally infected with a rough virulent strain of Brucella ovis (chronic 1 phase) GSE35614: Microarray analysis of gene expression in rams experimentally infected with a rough virulent strain of Brucella ovis (chronic 2 phase) Refer to individual Series
Project description:Brucellosis is one of the most common zoonotic epidemics worldwide. Vaccination against Brucellosis is an important control strategy to prevent the disease in many high-prevalence regions. At present, Brucella vaccine strain S2 is the most widely used vaccine in China. In this study, to uncover the related mechanisms underlie virulence attenuation of S2, we characterized the transcriptional profile of S2 and 1330 infected macrophages by transcriptome analysis. The results revealed that expressions of 440 genes were significantly different between macrophages infected by 1330 and S2. Data analysis showed that in the gene ontology term, the different expressed genes involved in innate immune response, phagoctyosis, recognition, and inflammatory response were significantly enriched. Pathway enrichment analysis indicated that the genes involved in transcriptional misregulation in cancer, staphylococcus aureus infection pathways and NF-kappa B signaling pathway were significantly affected. To reveal the molecular mechanisms related to different expression profiles of infected macrophages, the transcription levels of the different genes between the two bacterial genomes were also detected. In total, the transcription of 29 different genes was significantly changed in either culture medium or infected microphages. The results of current study can be conducive to the promotion of better understanding of the related mechanisms underlie virulence attenuation of S2 and interactions between host cells and brucella strains.