LAMBEDA PHAGE

Background: Recognition of bacteriophages in many aspects plays an important role such as controlling the number and variation of bacteria and participation in horizontal gene transfer, which is an important process in bacterial evolution. Bacteriophages use small proteins to take over the host molecular machinery and thus interfere with central metabolic processes in infected bacteria. In general, phages inhibit or reverse host transcription to transcribe their genome. Mechanical and structural studies of phage host transcription may lead to the development of new antibacterial agents. Result: The result shows that phage vB_Eco4M-7 must be a lytic virus. This was confirmed by monitoring faglitic development by a one-step growth test. In addition, phage of relatively small uniform plaques (1 mm in diameter) occur without lysogenesis. Electron microscopic analysis showed that vB_Eco4M-7 belongs to the family Myoviridae. Based on mass spectrometric analysis, including the fragmentation pattern of unique peptides, 33 vB_Eco4M-7 phage proteins are assigned to the annotated reading frames. The results indicate that the phage studied is a potential candidate for phage treatment and / or food protection against E. coli, which produce Shiga toxin, as most of these strains belong to the O157 serotype. Conclusion: In general, phages inhibit or reverse host transcription to transcribe their genome. Mechanical and structural studies of phage host transcription may lead to the development of new antibacterial agents. The result shows that phage vB_Eco4M-7 must be a lytic virus. This was confirmed by monitoring faglitic development by a one-step growth test.

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Bacteriophages vB_Sen-TO17 and vB_Sen-E22, Newly Isolated Viruses from Chicken Feces, Specific for Several Salmonella enterica Strains

International Journal of Molecular Sciences ◽

10.3390/ijms21228821 ◽

2020 ◽

Vol 21 (22) ◽

pp. 8821

Author(s):

Katarzyna Kosznik-Kwaśnicka ◽

Łukasz Grabowski ◽

Michał Grabski ◽

Mateusz Kaszubski ◽

Marcin Górniak ◽

...

Keyword(s):

Salmonella Enterica ◽

Functional Characterization ◽

Electron Microscopic ◽

Putative Gene ◽

Phylogenetic Studies ◽

Gene Coding ◽

Molecular Phylogenetic ◽

One Step ◽

Chicken Feces ◽

Step Growth

Two newly discovered bacteriophages, isolated from chicken feces and infecting Salmonella enterica strains, are described in this report. These phages have been named vB_Sen-TO17 and vB_Sen-E22, and we present their molecular and functional characterization. Both studied viruses are able to infect several S. enterica strains and develop lytically, but their specific host ranges differ significantly. Electron microscopic analyses of virions have been performed, and full genome sequences were determined and characterized, along with molecular phylogenetic studies. Genomes of vB_Sen-TO17 (ds DNA of 41,658 bp) and vB_Sen-E22 (dsDNA of 108,987 bp) are devoid of homologs of any known or putative gene coding for toxins or any other proteins potentially deleterious for eukaryotic cells. Both phages adsorbed efficiently (>95% adsorbed virions) within 10 min at 42 °C (resembling chicken body temperature) on cells of most tested host strains. Kinetics of lytic development of vB_Sen-TO17 and vB_Sen-E22, determined in one-step growth experiments, indicated that development is complete within 30–40 min at 42 °C, whereas burst sizes vary from 9 to 79 progeny phages per cell for vB_Sen-TO17 and from 18 to 64 for vB_Sen-E22, depending on the host strain. Virions of both phages were relatively stable (from several percent to almost 100% survivability) under various conditions, including acidic and alkaline pH values (from 3 to 12), temperatures from −80 °C to 60 °C, 70% ethanol, chloroform, and 10% DMSO. These characteristics of vB_Sen-TO17 and vB_Sen-E22 indicate that these phages might be considered in further studies on phage therapy, particularly in attempts to eliminate S. enterica from chicken intestine.

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Two-Dimensional Crystallization Procedure, from Protein Expression to Sample Preparation

BioMed Research International ◽

10.1155/2015/693869 ◽

2015 ◽

Vol 2015 ◽

pp. 1-10 ◽

Cited By ~ 1

Author(s):

Qie Kuang ◽

Pasi Purhonen ◽

Hans Hebert

Keyword(s):

Membrane Proteins ◽

General Idea ◽

General Description ◽

Two Dimensional ◽

Structural Studies ◽

Electron Crystallography ◽

Electron Microscopic ◽

Small Proteins ◽

Crystallization Procedure ◽

Related Proteins

Membrane proteins play important roles for living cells. Structural studies of membrane proteins provide deeper understanding of their mechanisms and further aid in drug design. As compared to other methods, electron microscopy is uniquely suitable for analysis of a broad range of specimens, from small proteins to large complexes. Of various electron microscopic methods, electron crystallography is particularly well-suited to study membrane proteins which are reconstituted into two-dimensional crystals in lipid environments. In this review, we discuss the steps and parameters for obtaining large and well-ordered two-dimensional crystals. A general description of the principle in each step is provided since this information can also be applied to other biochemical and biophysical methods. The examples are taken from our own studies and published results with related proteins. Our purpose is to give readers a more general idea of electron crystallography and to share our experiences in obtaining suitable crystals for data collection.

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Phage Xp12 of Xanthomonas oryzae (Uyeda et Ishiyama) Dowson

Canadian Journal of Microbiology ◽

10.1139/m68-190 ◽

1968 ◽

Vol 14 (10) ◽

pp. 1139-1142 ◽

Cited By ~ 5

Author(s):

Tsong-teh Kuo ◽

Tan-chi Huang ◽

Rong-yang Wu ◽

Chi-pien Chen

Keyword(s):

Deoxyribonucleic Acid ◽

Thermal Inactivation ◽

Sucrose Solution ◽

Burst Size ◽

Gradient Centrifugation ◽

Xanthomonas Oryzae ◽

Electron Microscopic ◽

Microscopic Studies ◽

One Step ◽

Step Growth

The properties of bacteriophage Xp12 of Xanthomonas oryzae, isolated from the water in a paddy field in Taiwan and found to contain 5-methylcytosine instead of cytosine, were studied. Phage preparations with high purity were obtained by a procedure involving differential centrifugation and density gradient centrifugation in sucrose solution. Electron microscopic studies revealed that this phage had a head of elliptical hexagonal outline which measured 76 × 55 mμ and a tail of 6 × 133 mμ. Phage Xp12 differed both morphologically and serologically from phages Xp10, Xp20, and Xf. The temperature of thermal inactivation for Xp12 was 66 °C. One step growth studies showed that the latent period for Xp12 was 140 minutes and the burst size was 35. According to the base ratio and composition of Xp12 nucleic acid, it was characteristically a highly ordered double-stranded deoxyribonucleic acid.

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Simultaneous Deletion of Pseudorabies Virus Tegument Protein UL11 and Glycoprotein M Severely Impairs Secondary Envelopment

Journal of Virology ◽

10.1128/jvi.78.6.3024-3034.2004 ◽

2004 ◽

Vol 78 (6) ◽

pp. 3024-3034 ◽

Cited By ~ 56

Author(s):

Martina Kopp ◽

Harald Granzow ◽

Walter Fuchs ◽

Barbara Klupp ◽

Thomas C. Mettenleiter

Keyword(s):

Pseudorabies Virus ◽

Plaque Formation ◽

Tegument Protein ◽

Electron Microscopic ◽

Glycoprotein E ◽

Intracytoplasmic Inclusions ◽

One Step ◽

Infected Cells ◽

Step Growth ◽

Growth Phenotype

ABSTRACT The pseudorabies virus (PrV) proteins UL11, glycoprotein E (gE), and gM are involved in secondary envelopment of tegumented nucleocapsids in the cytoplasm. To assess the relative contributions of these proteins to the envelopment process, virus mutants with deletions of either UL11, gM, or gE as well as two newly constructed mutant viruses with simultaneous deletions of UL11 and gE or of UL11 and gM were analyzed in cell culture for their growth phenotype. We show here that simultaneous deletion of UL11 and gE reduced plaque size in an additive manner over the reduction observed by deletion of only UL11 or gE. However, one-step growth was not further impaired beyond the level of the UL11 deletion mutant. Moreover, in electron microscopic analyses PrV-ΔUL11/gE exhibited a phenotype similar to that of the UL11 mutant virus. In contrast, plaque formation was virtually abolished by the simultaneous absence of UL11 and gM, and one-step growth was significantly reduced. Electron microscopy showed the presence of huge intracytoplasmic inclusions in PrV-ΔUL11/gM-infected cells, with a size reaching 3 μm and containing nucleocapsids embedded in tegument. We hypothesize that UL11 and gM are involved in different steps during secondary envelopment and that simultaneous deletion of both interrupts both processes, resulting in the observed drastic impairment of secondary envelopment.

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One step “growth to spinning” of biaxially multilayered CNT web electrode for long cycling Li-O2 batteries

Carbon ◽

10.1016/j.carbon.2021.06.031 ◽

2021 ◽

Author(s):

Young Shik Cho ◽

Hyunjin Kim ◽

Minhoo Byeon ◽

Yeonsu Jung ◽

DongJoon Lee ◽

...

Keyword(s):

One Step ◽

Step Growth

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T4-like Bacteriophages Isolated from Pig Stools Infect Yersinia pseudotuberculosis and Yersinia pestis Using LPS and OmpF as Receptors

Viruses ◽

10.3390/v13020296 ◽

2021 ◽

Vol 13 (2) ◽

pp. 296

Author(s):

Mabruka Salem ◽

Maria I. Pajunen ◽

Jin Woo Jun ◽

Mikael Skurnik

Keyword(s):

Yersinia Pseudotuberculosis ◽

Host Recognition ◽

Tail Fiber ◽

Long Tail ◽

Phage T4 ◽

One Step ◽

In Trans ◽

Step Growth ◽

Resistant Strains ◽

Salmonella Phage

The Yersinia bacteriophages fPS-2, fPS-65, and fPS-90, isolated from pig stools, have long contractile tails and elongated heads, and they belong to genus Tequatroviruses in the order Caudovirales. The phages exhibited relatively wide host ranges among Yersinia pseudotuberculosis and related species. One-step growth curve experiments revealed that the phages have latent periods of 50–80 min with burst sizes of 44–65 virions per infected cell. The phage genomes consist of circularly permuted dsDNA of 169,060, 167,058, and 167,132 bp in size, respectively, with a G + C content 35.3%. The number of predicted genes range from 267 to 271. The phage genomes are 84–92% identical to each other and ca 85% identical to phage T4. The phage receptors were identified by whole genome sequencing of spontaneous phage-resistant mutants. The phage-resistant strains had mutations in the ompF, galU, hldD, or hldE genes. OmpF is a porin, and the other genes encode lipopolysaccharide (LPS) biosynthetic enzymes. The ompF, galU, and hldE mutants were successfully complemented in trans with respective wild-type genes. The host recognition was assigned to long tail fiber tip protein Gp38, analogous to that of T-even phages such as Salmonella phage S16, specifically to the distal β-helices connecting loops.

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Aztreonam Lysine Increases the Activity of Phages E79 and phiKZ against Pseudomonas aeruginosa PA01

Microorganisms ◽

10.3390/microorganisms9010152 ◽

2021 ◽

Vol 9 (1) ◽

pp. 152

Author(s):

Carly M. Davis ◽

Jaclyn G. McCutcheon ◽

Jonathan J. Dennis

Keyword(s):

Pseudomonas Aeruginosa ◽

Morphological Changes ◽

Burst Size ◽

Type Iv Pili ◽

Biofilm Growth ◽

Promising Alternative ◽

Type Iv ◽

Alternative Treatment Option ◽

One Step ◽

Step Growth

Pseudomonas aeruginosa is a pernicious bacterial pathogen that is difficult to treat because of high levels of antibiotic resistance. A promising alternative treatment option for such bacteria is the application of bacteriophages; the correct combination of phages plus antibiotics can produce synergistic inhibitory effects. In this study, we describe morphological changes induced by sub-MIC levels of the antibiotic aztreonam lysine (AzLys) on P. aeruginosa PA01, which may in part explain the observed phage–antibiotic synergy (PAS). One-step growth curves for phage E79 showed increased adsorption rates, decreased infection latency, accelerated time to lysis and a minor reduction in burst size. Phage E79 plus AzLys PAS was also able to significantly reduce P. aeruginosa biofilm growth over 3-fold as compared to phage treatment alone. Sub-inhibitory AzLys-induced filamentation of P. aeruginosa cells resulted in loss of twitching motility and a reduction in swimming motility, likely due to a reduction in the number of polar Type IV pili and flagella, respectively, on the filamented cell surfaces. Phage phiKZ, which uses Type IV pili as a receptor, did not exhibit increased activity with AzLys at lower sub-inhibitory levels, but still produced phage–antibiotic synergistic killing with sub-inhibitory AzLys. A one-step growth curve indicates that phiKZ in the presence of AzLys also exhibits a decreased infection latency and moderately undergoes accelerated time to lysis. In contrast to prior PAS studies demonstrating that phages undergo delayed time to lysis with cell filamentation, these PAS results show that phages undergo accelerated time to lysis, which therefore suggests that PAS is dependent upon multiple factors, including the type of phages and antibiotics used, and the bacterial host being tested.

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The growth and assembly of the multidimensional hierarchical Ni3S2 for aqueous asymmetric supercapacitors

CrystEngComm ◽

10.1039/c4ce02558j ◽

2015 ◽

Vol 17 (24) ◽

pp. 4495-4501 ◽

Cited By ~ 33

Author(s):

Bin Yang ◽

Lei Yu ◽

Qi Liu ◽

Jingyuan Liu ◽

Wanlu Yang ◽

...

Keyword(s):

Thin Film ◽

Energy Storage ◽

High Performance ◽

Electrode Materials ◽

Hydrothermal Process ◽

Nanorod Arrays ◽

Asymmetric Supercapacitors ◽

One Step ◽

Step Growth

We synthesized the mushroom-like Ni3S2 with step by step growth that is the thin film growing on the nanorod arrays with one-step hydrothermal process, which is a novel ways to fabricate the multidimensional hierarchical electrode materials for high performance energy storage.

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