Isolation and partial characterization of a bacteriophage active on Hyphomicrobium sp. WI-926

1988 ◽  
Vol 34 (2) ◽  
pp. 101-106 ◽  
Author(s):  
W. C. Preissner ◽  
S. Maier ◽  
H. Völker ◽  
P. Hirsch
Keyword(s):  
Burst Size ◽  
Soft Agar ◽  
Single Step ◽  
Gram Positive Bacteria ◽  
Daughter Cells ◽  
Phage Adsorption ◽  
Individual Host ◽  
Filtration Enrichment ◽  
Phage Multiplication ◽  
Step Growth

Isolation of a Hyphomicrobium phage from raw sewage from Athens, Ohio, was achieved by a combination of differential centrifugation, filtration, enrichment in mixed Hyphomicrobium cultures, and purification on individual host strains by subculturing single plaques in soft agar overlayers. Enrichments with water from Lake Erie and Lake Beechwood (Ohio) were unsuccessful. Out of 21 Hyphomicrobium strains and 22 other Gram-negative and Gram-positive bacteria tested, only Hyphomicrobium WI-926 (isolated from a German forest pond) was susceptible. This phage had an isometric head (diameter between opposite apices, 67 nm) and a short (12 nm), noncontractile tail and belongs thus to the morphogroup C1. It contained double-stranded DNA. The single-step growth curve showed a latent period of 9 h, a rise period of 6 h, and a burst size of 35. The various differentiation stages in the host development exhibited different affinities for phage adsorption and development. While all stages allowed phage adsorption, the daughter cells were most efficient. Phage multiplication was limited to daughter cells, and the development of infected swarmer cells was arrested permanently at this stage.

scholarly journals Characterization of Bacteriophage against Enterococcus faecium Resistant to Vancomycin Isolated from Chicken Skin

2019 ◽  
pp. 1-14
Author(s):  
Hazzierah Syaffieqah An Nadiah Azlan ◽  
Muhajir Hamid ◽  
Adelene Ai-Lian Song
Keyword(s):  
Latent Period ◽  
Growth Kinetics ◽  
Enterococcus Faecium ◽  
Burst Size ◽  
Single Step ◽  
Vancomycin Resistant Enterococcus ◽  
Chicken Skin ◽  
Step Growth ◽  
Vancomycin Resistant ◽  
Faecium Strain

Aims: To characterize bacteriophages with strong in vitro lytic activity against vancomycin resistant Enterococcus faecium before testing on the chicken skin for their efficacy. Study Design: An experimental was carried out to characterize two isolated bacteriophages against Enterococcus faecium and test for their efficacy on chicken skin. Study Place: The study was carried out in Laboratory of Vaccine and Immunotherapeutics, Institue of Bioscience, Universiti Putra Malaysia in Selangor, which is the most populous state in Malaysia. Methodology: Two host specific lytic phages against vancomycin resistant Enterococcus faecium strain FM8, designated as FM8-P1 and FM8-P2 were physiological characterized. This includes determination of their adsorption rate, multiplicity of infection, and single step growth kinetics. The optimum pH and temperature for both bacteriophages activity were also determined before tested on chicken skin at 4°C and 25°C, which represent chiller and room temperature in poultry production line. Results: Based on the result of single-step growth kinetics, the latent period of FM8-P1 was 35 min with a burst size of 460 particles per infected cells, while FM8-P2 has a shorter latent period (20 min) but a smaller burst size of 60 particles. The highest adsorption rate for FM8-P1 was 83% and FM8-P2 was 90% at 2 min and 4 min respectively. Both bacteriophages also exihibited a wide range of pH and temperature for their activity. Conclusion: The specificity, lytic activity and stability of FM8-P1 and FM8-P2 emphasized their potential in effectively eliminating the vancomycin resistant Enterococcus faecium strain FM8. However, further works are required to validate their in situ reliability.

scholarly journals Characterization of Six Bacteriophages ofSerratia liquefaciens CP6 Isolated from the Sugar Beet Phytosphere

1999 ◽  
Vol 65 (5) ◽  
pp. 1959-1965 ◽  
Author(s):  
Kevin E. Ashelford ◽  
John C. Fry ◽  
Mark J. Bailey ◽  
Aaron R. Jeffries ◽  
Martin J. Day
Keyword(s):  
Sugar Beet ◽  
Burst Size ◽  
Single Step ◽  
The Other ◽  
Cross Hybridization ◽  
The Family ◽  
Step Growth ◽  
Natural Ecology ◽  
Changes Over Time

ABSTRACT Six phages (ΦCP6-1 to ΦCP6-6) that are commonly found in the phytosphere of sugar beet (Beta vulgaris var. Amethyst) were investigated, and their relative impacts on their host (Serratia liquefaciens CP6) were compared. There were fundamental differences between the two most abundant predators of CP6 (ΦCP6-1 and ΦCP6-4). Like ΦCP6-2 and ΦCP6-5, ΦCP6-1 belonged to the family Siphoviridae, while ΦCP6-4 exhibited the morphology of the family Podoviridae. The other phages were members of the family Myoviridae. DNA-DNA cross-hybridization revealed that ΦCP6-1 and ΦCP6-4 had little common DNA, although all of the other phages exhibited some genetic similarity. Like ΦCP6-2, ΦCP6-3, and ΦCP6-5, ΦCP6-1 was capable of forming a lysogenic association with its host, while ΦCP6-4 and ΦCP6-6 appeared to be entirely virulent. Single-step growth curve experiments revealed that ΦCP6-4 had a much shorter latent period and a smaller burst size than ΦCP6-1. Also, ΦCP6-1 could transduce a number of host chromosomal markers with transfer frequencies of 2.9 × 10−9 to 3.9 × 10−7, whereas ΦCP6-4 could not transduce S. liquefaciens CP6 genes. When viewed in the context of the strikingly different temporal niches of these phages, our data provide an insight into how bacteriophage interactions with their hosts might reflect the natural ecology of bacteriophages. Our data also illustrate how the potential for gene transfer changes over time in an environment that supports several different phages.

scholarly journals PH1: An Archaeovirus ofHaloarcula hispanicaRelated to SH1 and HHIV-2

Archaea ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-17 ◽  
Author(s):  
Kate Porter ◽  
Sen-Lin Tang ◽  
Chung-Pin Chen ◽  
Pei-Wen Chiang ◽  
Mei-Jhu Hong ◽  
...  
Keyword(s):  
Salt Lake ◽  
Burst Size ◽  
Growth Conditions ◽  
Single Step ◽  
Linear Dsdna ◽  
Step Growth ◽  
Terminal Proteins ◽  
Relationship Of ◽  
Haloarcula Hispanica ◽  
The Relationship

Halovirus PH1 infectsHaloarcula hispanicaand was isolated from an Australian salt lake. The burst size in single-step growth conditions was 50–100 PFU/cell, but cell density did not decrease until well after the rise (4–6 hr p.i.), indicating that the virus could exit without cell lysis. Virions were round, 51 nm in diameter, displayed a layered capsid structure, and were sensitive to chloroform and lowered salt concentration. The genome is linear dsDNA, 28,064 bp in length, with 337 bp terminal repeats and terminal proteins, and could transfect haloarchaeal species belonging to five different genera. The genome is predicted to carry 49 ORFs, including those for structural proteins, several of which were identified by mass spectroscopy. The close similarity of PH1 to SH1 (74% nucleotide identity) allowed a detailed description and analysis of the differences (divergent regions) between the two genomes, including the detection of repeat-mediated deletions. The relationship of SH1-like and pleolipoviruses to previously described genomic loci of virus and plasmid-related elements (ViPREs) of haloarchaea revealed an extensive level of recombination between the known haloviruses. PH1 is a member of the same virus group as SH1 and HHIV-2, and we propose the namehalosphaerovirusto accommodate these viruses.

Rapid Single-Step Growth of MOF Exoskeleton on Mammalian Cells for Enhanced Cytoprotection

2021 ◽  
Author(s):  
Laura Ha ◽  
UnJin Ryu ◽  
Dong-Chang Kang ◽  
Jung-Kyun Kim ◽  
Dengrong Sun ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Single Step ◽  
Step Growth

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

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.

scholarly journals Self-Crosslinked Ellipsoidal Poly(Tannic Acid) Particles for Bio-Medical Applications

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2429
Author(s):  
Nurettin Sahiner
Keyword(s):  
Tannic Acid ◽  
Hydrolytic Degradation ◽  
Single Step ◽  
Trolox Equivalent Antioxidant Capacity ◽  
Total Phenol Content ◽  
Frap Assay ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Trolox Equivalent ◽  
Free Media

Self-crosslinking of Tannic acid (TA) was accomplished to obtain poly(tannic acid) (p(TA)) particles in single step, surfactant free media using sodium periodate (NaIO4) as an oxidizing agent. Almost monodisperse p(TA) particles with 981 ± 76 nm sizes and −22 ± 4 mV zeta potential value with ellipsoidal shape was obtained. Only slight degradation of p(TA) particles with 6.8 ± 0.2% was observed at pH 7.4 in PBS up to 15 days because of the irreversible covalent formation between TA units, suggesting that hydrolytic degradation is independent from the used amounts of oxidation agents. p(TA) particles were found to be non-hemolytic up to 0.5 mg/mL concentration and found not to affect blood clotting mechanism up to 2 mg/mL concentration. Antioxidant activity of p(TA) particles was investigated by total phenol content (TPC), ferric reducing antioxidant potential (FRAP), trolox equivalent antioxidant capacity (TEAC), total flavanoid content (TFC), and Fe (II) chelating activity. p(TA) particles showed strong antioxidant capability in comparison to TA molecules, except FRAP assay. The antibacterial activity of p(TA) particles was investigated by micro-dilution technique on E. coli as Gram‑negative and S. aureus as Gram-positive bacteria and found that p(TA) particles are more effective on S. aureus with over 50% inhibition at 20 mg/mL concentration attained.

Single-step growth of CuInS2 nanospheres morphology thin films by electrospray chemical aerosol deposition technique

2019 ◽  
Vol 238 ◽  
pp. 206-209
Author(s):  
Logu Thirumalaisamy ◽  
Soundarrajan Palanivel ◽  
Ramesh Raliya ◽  
Shalinee Kavadiya ◽  
Kunjithapatham Sethuraman ◽  
...  
Keyword(s):  
Thin Films ◽  
Aerosol Deposition ◽  
Single Step ◽  
Deposition Technique ◽  
Step Growth

scholarly journals Autographa californica Nucleopolyhedrovirus orf69 Encodes an RNA Cap (Nucleoside-2′-O)-Methyltransferase

2003 ◽  
Vol 77 (6) ◽  
pp. 3430-3440 ◽  
Author(s):  
Xiaofeng Wu ◽  
Linda A. Guarino
Keyword(s):  
Late Phase ◽  
Growth Curves ◽  
Immunoblot Analysis ◽  
Single Step ◽  
Coding Region ◽  
Methyltransferase Activity ◽  
Autographa Californica Nucleopolyhedrovirus ◽  
High Conservation ◽  
Step Growth

ABSTRACT The AcNPV orf69 gene encodes a protein that contains an S-adenosylmethionine (AdoMet)-dependent methyltransferase signature motif. More significantly, ORF69 shows high conservation at residues diagnostic for (nucleoside 2′-O)-methyltransferase activity. To analyze the function of this protein, which was renamed MTase1, it was overexpressed in Escherichia coli and purified to homogeneity. Photo cross-linking experiments showed that MTase1 bound AdoMet, and functional assays demonstrated cap 0-dependent methyltransferase activity. In vivo expression assays in insect cells showed that MTase1 was synthesized during the late phase of infection and that its expression was dependent on viral DNA replication. Primer extension analysis identified a late promoter motif, ATAAG, at the transcription start site. A mutant virus was constructed by inserting the lacZ gene into the coding region of mtase1. Immunoblot analysis confirmed that MTase1 was not synthesized in these cells, and single-step growth curves revealed that the rate of virus replication in tissue culture was not affected by the absence of MTase1.

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