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ABSTRACT:
PROVIDER: PRJNA750911 | ENA |
REPOSITORIES: ENA
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Project description:Cyanobacteria are highly abundant in the oceans where they are constantly exposed to lytic viruses. Some viruses are restricted to a narrow host range while others infect a broad range of hosts. It is currently unknown whether broad-host range phages employ the same infection program, or regulate their program in a host-specific manner to accommodate for the different genetic makeup and defense systems of each host. Here we used a combination of microarray and RNA-seq analyses to investigate the interaction of three phylogentically distinct Synechococcus strains, WH7803, WH8102, and WH8109, with the broad-host range T4-like myovirus, Syn9, during infection. Strikingly, we found that the phage led a nearly identical expression program in the three hosts despite considerable differences in host gene content. On the other hand, host responses to infection involved mainly host-specific genes, suggesting variable attempts at defense against infection. A large number of responsive host genes were located in hypervariable genomic islands, substantiating genomic islands as a major axis of phage-bacteria interactions in cyanobacteria. Furthermore, transcriptome analyses and experimental determination of the complete phage promoter map revealed three temporally regulated modules and not two as previously thought for cyanophages. In contrast to T4, an extensive, previously unknown regulatory motif drives expression of early genes and host-like promoters drive middle-gene expression. These promoters are highly conserved among cyanophages and host-like middle promoters extend to other T4-like phages, indicating that the well-known mode of regulation in T4 is not the rule among the broad family of T4-like phages. We investigated the infection process and transcriptional program of the P-TIM40 cyanophage during infection of a Prochlorococcus NATL2A host. The results are discussed in conjunction with results obtained from the infection process for the Syn9 cyanophage in three different Synechococcus hosts: WH7803 (Dufresne et al. 2008), WH8102 (Palenik et al. 2003) and WH8109 (sequenced as part of this study).
2015-08-30 | E-GEOD-63690 | biostudies-arrayexpress
Project description:ϕXacN1 is a novel jumbo myovirus infecting the causative agent of Asian citrus canker, Xanthomonas citri. Its linear 384,670 bp double-stranded DNA genome encodes 592 predicted protein coding genes and shows 65,875 bp direct terminal repeats (DTRs), so far the longest DTRs among sequence phage genomes. The DTRs harbor 56 tRNA genes, corresponding to all 20 amino acids. This is the highest number of tRNA genes reported in a phage genome. Codon usage analyses revealed a propensity that the phage encoded tRNAs target codons that are highly used by the phage but less frequently by its host. The existence of these tRNA genes, additional seven translation-related genes as well as a chaperonin gene found in the ϕXacN1 genome suggests an increased level of independence of phage replication on host molecular machinery and a wide host range. Consistently, ϕXacN1 showed a wider host range than other X. citri phages in an infection test against a panel of X. citri strains. Phylogenetic analyses revealed a clade of phages composed of ϕXacN1 and ten other jumbo phages showing an evolutionary stability in their large genome sizes.
2018-10-30 | PXD008065 | JPOST Repository
Project description:Antibiotic use can lead to expansion of multi-drug resistant pathobionts within the gut microbiome that can cause life-threatening infections. Selective alternatives to conventional antibiotics are in dire need. Here, we describe a Klebsiella PhageBank that enables the rapid design of antimicrobial bacteriophage cocktails to treat multi-drug resistant Klebsiella pneumoniae. Using a transposon library in carbapenem-resistant K. pneumoniae, we identified host factors required for phage infection in major Klebsiella phage families. Leveraging the diversity of the PhageBank and experimental evolution strategies, we formulated combinations of phages that minimize the occurrence of phage resistance in vitro. Optimized bacteriophage cocktails selectively suppressed the burden of multi-drug resistant K. pneumoniae in the mouse gut microbiome and drove bacterial populations to lose key virulence factors that act as phage receptors. Further, phage-mediated diversification of bacterial populations in the gut enabled co-evolution of phage variants with higher virulence and a broader host range. Altogether, the Klebsiella PhageBank represents a roadmap for both phage researchers and clinicians to enable phage therapy against a critical multidrug-resistant human pathogen.
2024-10-01 | GSE272297 | GEO
Project description:Klebsiella pneumoniae has risen to prominence as a major threat to human health, with hypervirulent and drug-resistant lineages spreading globally. Given their antimicrobial resistant phenotypes, new therapies are required for the treatment of these infections, and bacteriophages (phages) that kill Klebsiella are being identified for use in phage therapy. In order to circumvent the evolution of phage-resistance taking hold the way that drug-resistance has, clear and considered actions are needed in selecting the phages that would be used in therapeutic cocktails. It is known that annotation of phage genomes is poor, potentially obscuring those phages with the most therapeutic potential. Here we show that phages isolated from infrequently sampled environments have features of therapeutic potential and developed a computational tool called STEP3 to understand the evolutionary features that distinguish the component parts of diverse phages, features that proved particularly suitable to detection of virion proteins with only distantly related homologies. These features were integrated into an ensemble framework to achieve a stable and robust prediction performance by STEP3. Proteomics-based analysis of two phages validated the prediction accuracy of STEP3 and revealed the virions contain component parts that include DNA-binding factors, otherwise unrecognizable capsule degradation enzymes and membrane translocation factors.
2021-04-30 | PXD020607 | Pride
Project description:Cyanobacteria are highly abundant in the oceans and are constantly exposed to lytic viruses. The T4-like cyanomyoviruses are abundant in the marine environment and have broad host ranges relative to other cyanophages. It is currently unknown whether broad-host-range phages specifically tailor their infection program for each host, or employ the same program irrespective of the host infected. Also unknown is how different hosts respond to infection by the same phage. Here we used microarray and RNA-seq analyses to investigate the interaction between the Syn9 T4-like cyanophage and three phylogenetically, ecologically and genomically distinct marine Synechococcus strains: WH8102, WH7803 and WH8109. Strikingly, Syn9 led a nearly identical infection and transcriptional program in all three hosts. Different to previous assumptions for T4-like cyanophages, three temporally regulated gene expression classes were observed. Furthermore, a novel regulatory element controlled early gene transcription, and host-like promoters drove middle gene transcription, different to the regulatory paradigm for T4. Similar results were found for the P-TIM40 phage during infection of Prochlorococcus NATL2A. Moreover, genomic and metagenomic analyses indicate that these regulatory elements are abundant and conserved among T4-like cyanophages. In contrast to the near-identical transcriptional program employed by Syn9, host responses to infection involved host-specific genes primarily located in hypervariable genomic islands, substantiating islands as a major axis of phage-cyanobacteria interactions. Our findings suggest that the ability of broad host-range phages to infect multiple hosts is more likely dependent on the effectiveness of host defense strategies than on differential tailoring of the infection process by the phage.
2015-08-30 | GSE63690 | GEO
Project description:Cyanobacteria are highly abundant in the oceans and are constantly exposed to lytic viruses. The T4-like cyanomyoviruses are abundant in the marine environment and have broad host ranges relative to other cyanophages. It is currently unknown whether broad-host-range phages specifically tailor their infection program for each host, or employ the same program irrespective of the host infected. Also unknown is how different hosts respond to infection by the same phage. Here we used microarray and RNA-seq analyses to investigate the interaction between the Syn9 T4-like cyanophage and three phylogenetically, ecologically and genomically distinct marine Synechococcus strains: WH8102, WH7803 and WH8109. Strikingly, Syn9 led a nearly identical infection and transcriptional program in all three hosts. Different to previous assumptions for T4-like cyanophages, three temporally regulated gene expression classes were observed. Furthermore, a novel regulatory element controlled early gene transcription, and host-like promoters drove middle gene transcription, different to the regulatory paradigm for T4. Similar results were found for the P-TIM40 phage during infection of Prochlorococcus NATL2A. Moreover, genomic and metagenomic analyses indicate that these regulatory elements are abundant and conserved among T4-like cyanophages. In contrast to the near-identical transcriptional program employed by Syn9, host responses to infection involved host-specific genes primarily located in hypervariable genomic islands, substantiating islands as a major axis of phage-cyanobacteria interactions. Our findings suggest that the ability of broad host-range phages to infect multiple hosts is more likely dependent on the effectiveness of host defense strategies than on differential tailoring of the infection process by the phage.
2015-11-13 | GSE74921 | GEO
Project description:Oomycetes, such as the broad host-range necrotrophic plant pathogen Pythium myriotylum, cause devastating crop losses. We have previously identified P. myriotylum as the major pathogen infecting ginger (Zingiber officinale) rhizomes in China with symptoms of Pythium soft rot (PSR) disease. Ginger is an important crop with global production estimated at approximately three million metric tonnes with about 20% of this production in China. To better understand how P. myriotylum infects ginger, transcriptomic analysis was performed on two P. myriotylum isolates (SWQ7 and SL2) infecting ginger leaves. From both of the isolates, there was a clear separation between the transcriptome replicates from the mycelial control condition and those from the infection of the ginger leaf. In SWQ7 and SL2, there were 2,110 and 2,513 genes upregulated during infection of ginger, respectively. Of the putative effectors, a subset of the NEP1-like toxin protein (NLP) effectors were highly induced during the infection of ginger leaves. Insights from the transcriptome highlight the important role of a subset of plant cell wall degrading enzymes (PCWDEs) and effectors in the pathogenicity of P. myriotylum towards ginger. The surprisingly large numbers of P. myriotylum PCWDEs and effectors within the genome may be due to the broad host-range of P. myriotylum whereby particular subsets of the PCWDEs and effectors are required for pathogenicity towards particular hosts.
2022-07-22 | GSE174557 | GEO
Project description:Klebsiella pneumoniae is an arising threat to human health. However, host immune responses in response to this bacterium remain to be elucidated. The goal of this study was to identify the dominant host immune responses associated with Klebsiella pneumoniae pulmonary infection. Pulmonary mRNA profiles of 6-8-weeks-old BALB/c mice infected with/without Klebsiella pneumoniae were generated by deep sequencing using Illumina Novaseq 6000. qRT–PCR validation was performed using SYBR Green assays. Using KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis, we identified several immune associated pathways, including complement and coagulation cascades, Toll-like receptor signaling pathway, Rap1 signaling pathway, chemokine signaling pathway, TNF signaling pathway, phagosome and NOD-like receptor signaling pathway, were involved in Klebsiella pneumoniae pulmonary infection. Using ICEPOP (Immune CEll POPulation) analysis, we found that several cell types were involved in the host immune response to Klebsiella pneumoniae pulmonary infection, including dendritic cells, macrophages, monocytes, NK (natural killer) cells, stromal cells. Further, IL-17 chemokines were significantly increased during Klebsiella pneumoniae infection. This study provided evidence for further studying the pathogenic mechanism of Klebsiella pneumoniae pneumonia infection.
2021-03-30 | GSE171048 | GEO