Project description:The phage protein gp70.1 encoded by Pseudomonas aerugonosa phage PaP3 was toxic to both P. aerugonosa and E. coli, microarry analysis was used to investigate the effects of gp70.1 on P. aerugonosa with three periods of bacterial growth.
Project description:Pseudomonas syringae pv. phaseolicola (Pph) is a significant bacterial pathogen of agricultural crops, and phage Φ6 and other members of the dsRNA virus family Cystoviridae undergo lytic (virulent) infection of Pph, using the type IV pilus as the initial site of cellular attachment. Despite the popularity of Pph/phage Φ6 as a model system in evolutionary biology, Pph resistance to phage Φ6 remains poorly characterized. To investigate differences between phage Φ6 resistant Pseudomonas syringae pathovar phaseolicola strains, we performed expression analysis of super and non piliated strains of Pseudomonas syringae to determine the genetic cause of resistance to viral infection.
Project description:Pseudomonas aeruginosa bacteriophage PhiKZ is the type representative of the M-bM-^@M-^XgiantM-bM-^@M-^Y phage genus with unusually large virions and genomes. By unraveling the transcriptional map of the 280 kb genome to single-nucleotide resolution, we show that it encodes 369 genes organized in 134 operons, 20% more than originally annotated. Early transcription is initiated from 28 highly conserved AT-rich promoters distributed over the PhiKZ genome, all located on the same strand. Transcription of middle and late genes is dependent on protein synthesis and mediated by very poorly conserved middle (6) and late (16) promoters. As a result of massive PhiKZ transcription, halfway through infection only 1.5% of all mRNAs in the infected cell remain bacterial. Unique to PhiKZ is its ability to complete its infection in complete absence of bacterial RNA polymerase (RNAP) enzyme activity. Its transcription is performed by the consecutive action of two PhiKZ-encoded, non-canonical RNAPs, one of which is packed within the virion. This unique, rifampicin-resistant transcriptional machinery is conserved among giant viruses, seems to function without auxiliary factors and might have its origin preceding the split between Gram-positive and Gram-negative bacteria. Construction of transcription maps for the PhiKZ phage and analysis of differential expression of host and phage genes using RNA-Seq data from samples taken in duplicate at 0, 5, 10, 15, and 35 minutes into infection.
Project description:Differential RNA-seq (dRNA-seq) was performed on Pseudomonas aeruginosa alone or shortly after iinfection with the jumbo phage phiKZ
Project description:Quorum sensing (QS) is the cell density-dependent virulence factor regulator in Pseudomonas aeruginosa. Here, we elucidate PIT2, a phage-encoded inhibitor of the QS regulator LasR, derived from the lytic Pseudomonas phage LMA2. PIT2 inhibits the effectors PrpL and LasA of the type 2 secretion system of P. aeruginosa and attenuates bacterial virulence towards HeLa cells and in Galleria mellonella. Using RNAseq-based differential gene expression analysis, the effect of PIT2 on the LasR regulatory network was revealed. Moreover, the specific interaction between LasR and PIT2 was determined. These data expand our knowledge on phage-encoded modulators of the bacterial metabolism, as this examples an anti-virulence protein derived from a lytic phage. From an applied perspective, this phage protein reveals and exploits an interesting anti-virulence target in P. aeruginosa. As such, it lays the foundation for a new phage-inspired anti-virulence strategy to combat multidrug resistant pathogens and opens the door for SynBio applications.
Project description:The global transcriptional profile of novel T7-like Pseudomonas aeruginosa phage LUZ100 was obtained using the long read RNA sequencing technique ONT-cappable-seq. Using this approach we obtained a comprehensive genome-wide map of viral transcription start sites, terminators and transcription units and gained new insights in the molecular mechanisms of transcriptional regulation of T7-like temperate phages.
