scholarly journals Discovery of Three Toxic Proteins of Klebsiella Phage fHe-Kpn01

Viruses ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 544
Author(s):  
Cindy M. Spruit ◽  
Anu Wicklund ◽  
Xing Wan ◽  
Mikael Skurnik ◽  
Maria I. Pajunen
Keyword(s):  
Virulence Genes ◽  
Phage Therapy ◽  
Sewage Water ◽  
Lytic Phage ◽  
Gene Products ◽  
Proteomics Analysis ◽  
Narrow Host Range ◽  
Extended Spectrum Beta Lactamase ◽  
The Family ◽  
Associated Proteins

The lytic phage, fHe-Kpn01 was isolated from sewage water using an extended-spectrum beta-lactamase-producing strain of Klebsiella pneumoniae as a host. The genome is 43,329 bp in size and contains direct terminal repeats of 222 bp. The genome contains 56 predicted genes, of which proteomics analysis detected 29 different proteins in purified phage particles. Comparison of fHe-Kpn01 to other phages, both morphologically and genetically, indicated that the phage belongs to the family Podoviridae and genus Drulisvirus. Because fHe-Kpn01 is strictly lytic and does not carry any known resistance or virulence genes, it is suitable for phage therapy. It has, however, a narrow host range since it infected only three of the 72 tested K. pneumoniae strains, two of which were of capsule type KL62. After annotation of the predicted genes based on the similarity to genes of known function and proteomics results on the virion-associated proteins, 22 gene products remained annotated as hypothetical proteins of unknown function (HPUF). These fHe-Kpn01 HPUFs were screened for their toxicity in Escherichia coli. Three of the HPUFs, encoded by the genes g10, g22, and g38, were confirmed to be toxic.

scholarly journals Identification and Functional Analysis of Temperate Siphoviridae Bacteriophages of Acinetobacter baumannii

Viruses ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 604 ◽  
Author(s):  
Shimaa Badawy ◽  
Maria I. Pajunen ◽  
Johanna Haiko ◽  
Zakaria A. M. Baka ◽  
Mohamed I. Abou-Dobara ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Trna Gene ◽  
Phage Therapy ◽  
Morphological Characteristics ◽  
Opportunistic Pathogen ◽  
Clinical Strains ◽  
Narrow Host Range ◽  
Clinical Challenge ◽  
Transmission Electron ◽  
The Family

Acinetobacter baumannii is an opportunistic pathogen that presents a serious clinical challenge due to its increasing resistance to all available antibiotics. Phage therapy has been introduced recently to treat antibiotic-incurable A. baumannii infections. In search for new A. baumannii specific bacteriophages, 20 clinical A. baumannii strains were used in two pools in an attempt to enrich phages from sewage. The enrichment resulted in induction of resident prophage(s) and three temperate bacteriophages, named vB_AbaS_fEg-Aba01, vB_AbaS_fLi-Aba02 and vB_AbaS_fLi-Aba03, all able to infect only one strain (#6597) of the 20 clinical strains, were isolated. Morphological characteristics obtained by transmission electron microscopy together with the genomic information revealed that the phages belong to the family Siphoviridae. The ca. 35 kb genomic sequences of the phages were >99% identical to each other. The linear ds DNA genomes of the phages contained 10 nt cohesive end termini, 52–54 predicted genes, an attP site and one tRNA gene each. A database search revealed an >99% identical prophage in the genome of A. baumannii strain AbPK1 (acc. no. CP024576.1). Over 99% identical prophages were also identified from two of the original 20 clinical strains (#5707 and #5920) and both were shown to be spontaneously inducible, thus very likely being the origins of the isolated phages. The phage vB_AbaS_fEg-Aba01 was also able to lysogenize the susceptible strain #6597 demonstrating that it was fully functional. The phages showed a very narrow host range infecting only two A. baumannii strains. In conclusion, we have isolated and characterized three novel temperate Siphoviridae phages that infect A. baumannii.

scholarly journals Transcription of Candidate Virulence Genes ofHaemophilus ducreyi during Infection of Human Volunteers

2001 ◽  
Vol 69 (3) ◽  
pp. 1483-1487 ◽  
Author(s):  
Robert E. Throm ◽  
Stanley M. Spinola
Keyword(s):  
Experimental Infection ◽  
Virulence Genes ◽  
Human Model ◽  
Specific Gene ◽  
Gene Products ◽  
Virulence Determinants ◽  
Reverse Transcription Pcr ◽  
Human Volunteers

ABSTRACT Haemophilus ducreyi expresses several putative virulence factors in vitro. Isogenic mutant-to-parent comparisons have been performed in a human model of experimental infection to examine whether specific gene products are involved in pathogenesis. Several mutants (momp, ftpA, losB, lst, cdtC, and hhdB) were as virulent as the parent in the human model, suggesting that their gene products did not play a major role in pustule formation. However, we could not exclude the possibility that the gene of interest was not expressed during the initial stages of infection. Biopsies of pustules obtained from volunteers infected with H. ducreyiwere subjected to reverse transcription-PCR. Transcripts corresponding to momp, ftpA, losB, lst, cdtB, and hhdA were expressed in vivo. In addition, transcripts for other putative virulence determinants such as ompA2, tdhA, lspA1, andlspA2 were detected in the biopsies. These results indicate that although several candidate virulence determinants are expressed during experimental infection, they do not have a major role in the initial stages of pathogenesis.

Complete Genome Sequence of Bacteriophage EFC1 Infecting Enterococcus Faecalis From Chicken

2021 ◽  
Author(s):  
Qi Wang ◽  
Na Liu
Keyword(s):  
Enterococcus Faecalis ◽  
Virulence Genes ◽  
Large Subunit ◽  
Antibiotic Resistance Genes ◽  
Lytic Phage ◽  
High Similarity ◽  
Protein Coding ◽  
Circular Dna ◽  
Intron Structure ◽  
Comparative Phylogenetic Analysis

Abstract In response to Enterococcus faecalis infection of chicken origin, a multi host lytic phage, EFC1 was isolated and characterized the double-stranded circular DNA genome with size of 56099 bp, containing 89 predicted protein coding genes as well as 2 tRNAs involved in intron, structure, transcription, packaging, DNA replication, modification, lysis. Observation of the structure by electron microscopy and comparative phylogenetic analysis of terminase large subunit showed that the phage EFC1 belongs to a new member of Siphoviridae, which is relatively distantly related to its high similarity phages. The phage EFC1 has no relevant virulence genes and antibiotic resistance genes.

scholarly journals PnuC and the Utilization of the Nicotinamide Riboside Analog 3-Aminopyridine in Haemophilus influenzae

2004 ◽  
Vol 48 (12) ◽  
pp. 4532-4541 ◽  
Author(s):  
Elizabeta Sauer ◽  
Melisa Merdanovic ◽  
Anne Price Mortimer ◽  
Gerhard Bringmann ◽  
Joachim Reidl
Keyword(s):  
Haemophilus Influenzae ◽  
Pasteurella Multocida ◽  
Growth Inhibitor ◽  
Narrow Host Range ◽  
Nicotinamide Riboside ◽  
E Coli ◽  
Nicotinamide Mononucleotide ◽  
The Family ◽  
Serovar Typhimurium ◽  
Utilization Pathway

ABSTRACT The utilization pathway for the uptake of NAD and nicotinamide riboside was previously characterized for Haemophilus influenzae. We now report on the cellular location, topology, and substrate specificity of PnuC. pnuC of H. influenzae is only distantly related to pnuC of Escherichia coli and Salmonella enterica serovar Typhimurium. When E. coli PnuC was expressed in an H. influenzae pnuC mutant, it was able to take up only nicotinamide riboside and not nicotinamide mononucleotide. Therefore, we postulated that PnuC transporters in general possess specificity for nicotinamide riboside. Earlier studies showed that 3-aminopyridine derivatives (e.g., 3-aminopyridine adenine dinucleotide) are inhibitory for H. influenzae growth. By testing characterized strains with mutations in the NAD utilization pathway, we show that 3-aminopyridine riboside is inhibitory to H. influenzae and is taken up by the NAD-processing and nicotinamide riboside route. 3-Aminopyridine riboside is utilized effectively in a pnuC+ background. In addition, we demonstrate that 3-aminopyridine adenine dinucleotide resynthesis is produced by NadR. 3-Aminopyridine riboside-resistant H. influenzae isolates were characterized, and mutations in nadR could be detected. We also tested other species of the family Pasteurellaceae, Pasteurella multocida and Actinobacillus actinomycetemcomitans, and found that 3-aminopyridine riboside does not act as a growth inhibitor; hence, 3-aminopyridine riboside represents an anti-infective agent with a very narrow host range.

Bacteriophage gene products as potential antimicrobials against tuberculosis

2019 ◽  
Vol 47 (3) ◽  
pp. 847-860 ◽  
Author(s):  
Maria Puiu ◽  
Christina Julius
Keyword(s):  
Phage Therapy ◽  
Basic Research ◽  
Gene Products ◽  
Cellular Processes ◽  
Tb Treatment ◽  
Current State ◽  
Rapid Spread ◽  
Long Time ◽  
State Of Research ◽  
Host Target

Abstract Tuberculosis (TB) is recognised as one of the most pressing global health threats among infectious diseases. Bacteriophages are adapted for killing of their host, and they were exploited in antibacterial therapy already before the discovery of antibiotics. Antibiotics as broadly active drugs overshadowed phage therapy for a long time. However, owing to the rapid spread of antibiotic resistance and the increasing complexity of treatment of drug-resistant TB, mycobacteriophages are being studied for their antimicrobial potential. Besides phage therapy, which is the administration of live phages to infected patients, the development of drugs of phage origin is gaining interest. This path of medical research might provide us with a new pool of previously undiscovered inhibition mechanisms and molecular interactions which are also of interest in basic research of cellular processes, such as transcription. The current state of research on mycobacteriophage-derived anti-TB treatment is reviewed in comparison with inhibitors from other phages, and with focus on transcription as the host target process.

All in the Family: Primary Megakaryocytes for Studies of Platelet αIIbβ3 Signaling

2001 ◽  
Vol 86 (07) ◽  
pp. 259-265 ◽  
Author(s):  
Andrew Leavitt ◽  
Sanford Shattil
Keyword(s):  
Molecular Basis ◽  
Intrinsic Value ◽  
Model System ◽  
Integrin Signaling ◽  
Gene Products ◽  
Hematopoietic Stem ◽  
The Family ◽  
Viral Transduction ◽  
Inside Out ◽  
Platelet Formation

SummaryIntegrin αIIbβ3 mediates key platelet adhesive responses during hemostasis and thrombosis. Adhesive ligand binding to αIIbβ3 is regulated by “inside-out” signals, while adhesion-dependent cytoskeletal events are regulated by “outside-in” signals from αIIbβ3. Currently, the molecular basis of bidirectional αIIbβ3 signaling is incompletely understood. The functional assessment of integrin signaling pathways in nucleated cells has been facilitated by techniques such as viral transduction which enable expression of dominant-active and dominant-inhibitory gene products. This approach cannot be used with anucleate platelets. However, recent advances in the ability to expand human and murine megakaryocytes from hematopoietic stem cells provide a tractable and genetically manipulatable system for studies of αIIbβ3 signaling. This overview will discuss some of the advantages and limitations of this approach and provide examples of its utility. Thus, in addition to their intrinsic value for understanding hematopoiesis and platelet formation, primary megakaryocytes represent a model system complementary to platelets for unraveling the remaining mysteries of αIIbβ3 signaling.

scholarly journals Multiplex proteomics analysis of gender-associated proteins in Brugia malayi

2012 ◽  
Vol 42 (9) ◽  
pp. 841-850 ◽  
Author(s):  
Daojun Jiang ◽  
James Malone ◽  
Reid Townsend ◽  
Gary J. Weil ◽  
Benwen Li
Keyword(s):  
Brugia Malayi ◽  
Proteomics Analysis ◽  
Associated Proteins

scholarly journals Identification of Tissue-Restricted Transcripts in Human Islets

Endocrinology ◽  
2004 ◽  
Vol 145 (10) ◽  
pp. 4513-4521 ◽  
Author(s):  
Antonella Maffei ◽  
Zhuoru Liu ◽  
Piotr Witkowski ◽  
Federica Moschella ◽  
Giovanna Del Pozzo ◽  
...  
Keyword(s):  
Gene Expression ◽  
Islet Cell ◽  
Ex Vivo ◽  
Expression Profiles ◽  
Kidney Tissue ◽  
Gene Expression Profiles ◽  
Human Islets ◽  
Gene Products ◽  
Associated Proteins

Abstract The purpose of our study was to identify transcripts specific for tissue-restricted, membrane-associated proteins in human islets that, in turn, might serve as markers of healthy or diseased islet cell masses. Using oligonucleotide chips, we obtained gene expression profiles of human islets for comparison with the profiles of exocrine pancreas, liver, and kidney tissue. As periislet presence of type 1 interferon is associated with the development of type 1 diabetes, the expression profile of human islets treated ex vivo with interferon-α2β (IFNα2β) was also determined. A set of genes encoding transmembrane- or membrane-associated proteins with novel islet-restricted expression was resolved by determining the intersection of the islet set with the complement of datasets obtained from other tissues. Under the influence of IFNα2β, the expression levels of transcripts for several of the identified gene products were up- or down-regulated. One of the islet-restricted gene products identified in this study, vesicular monoamine transporter type 2, was shown to bind [3H]dihydrotetrabenazine, a ligand with derivatives suitable for positron emission tomography imaging. We report here the first comparison of gene expression profiles of human islets with other tissues and the identification of a target molecule with possible use in determining islet cell masses.

scholarly journals The effect of lipocalin-2 (LCN2) on apoptosis: a proteomics analysis study in an LCN2 deficient mouse model

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Dongming Wu ◽  
Xiaopeng Wang ◽  
Ye Han ◽  
Yayun Wang
Keyword(s):  
Knockout Mice ◽  
Quantitative Proteomics ◽  
Energy Homeostasis ◽  
Metabolic Diseases ◽  
Differentially Expressed Proteins ◽  
Label Free ◽  
Lipocalin 2 ◽  
Wild Type ◽  
Proteomics Analysis ◽  
Associated Proteins

Abstract Background Recent studies have shown that lipocalin-2 (LCN2) has multiple functions involved in various biological and pathological processes including energy homeostasis, cancer, inflammation, and apoptosis. We aimed to investigate the effect of LCN2 on apoptosis that influences the pathogenetic process of metabolic diseases and cancer. Methods We performed a proteomics analysis of livers taken from LCN2-knockout mice and wild type mice by using label-free LC-MS/MS quantitative proteomics. Results Proteomic analysis revealed that there were 132 significantly differentially expressed proteins (49 upregulated and 83 downregulated) among 2140 proteins in the liver of LCN2-knockout mice compared with wild type mice. Of these, seven apoptosis-associated proteins were significantly upregulated and seven apoptosis-associated proteins downregulated. Conclusion Proteomics demonstrated that there were seven upregulated and seven downregulated apoptosis-associated proteins in liver of LCN2-knockout mice. It is important to clarify the effect of LCN2 on apoptosis that might contribute to the pathogenesis of insulin resistance, cancer, and various nervous system diseases.

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