scholarly journals Characterization of the Bacteriophage vB_EfaS-271 Infecting Enterococcus faecalis

2020 ◽  
Vol 21 (17) ◽  
pp. 6345
Author(s):  
Gracja Topka-Bielecka ◽  
Sylwia Bloch ◽  
Bożena Nejman-Faleńczyk ◽  
Michał Grabski ◽  
Agata Jurczak-Kurek ◽  
...  

A newly isolated bacteriophage infecting Enterococcus faecalis strains has been characterized, including determination of its molecular features. This phage, named vB_EfaS-271, has been classified as a Siphoviridae member, according to electron microscopy characterization of the virions, composed of a 50 nm-diameter head and a long, flexible, noncontractable tail (219 × 12.5 nm). Analysis of the whole dsDNA genome of this phage showed that it consists of 40,197 bp and functional modules containing genes coding for proteins that are involved in DNA replication (including DNA polymerase/primase), morphogenesis, packaging and cell lysis. Mass spectrometry analysis allowed us to identify several phage-encoded proteins. vB_EfaS-271 reveals a relatively narrow host range, as it is able to infect only a few E. faecalis strains. On the other hand, it is a virulent phage (unable to lysogenize host cells), effectively and quickly destroying cultures of sensitive host bacteria, with a latent period as short as 8 min and burst size of approximately 70 phages per cell at 37 °C. This phage was also able to destroy biofilms formed by E. faecalis. These results contribute to our understanding of the biodiversity of bacteriophages, confirming the high variability among these viruses and indicating specific genetic and functional features of vB_EfaS-271.

2021 ◽  
Author(s):  
Manoj Kumawat ◽  
Irungbam Karuna ◽  
Divya Chaudhary ◽  
Neeraj Ahlawat ◽  
Bilkees Nabi ◽  
...  

Abstract Salmonella Typhimurium (ST) is the zoonotic pathogenic Gram-negative bacteria to causes infectious disease in humans as well as in animals. It causes gastrointestinal illness and fever called salmonellosis, which is foodborne diarrheal and leading cause of millions of deaths worldwide. Salmonella enterica serovar Typhimurium (S. Typhimurium) during its pathogenesis takeaway the actin cytoskeleton of their host cells and this is the crucial step of its infection cycle. Cyclophilin A, a type of peptidyl-prolyl isomerase that’s encoded by the ppiA gene in ST, plays pleiotropic roles in maintaining bacterial physiology. In this research, the proteomic characterization of the peptidyl-prolyl cis-trans isomerase- A (Cyclophilin A) from Salmonella Typhimurium is reported. Cyclophilin A (CypA) protein from Salmonella Typhimurium proved to be a highly conserved protein sequence and highly homologous compared to other organisms. This protein was expressed in Escherichia coli and then purified in a recombinant form protein exhibited a characteristic PPIases activity (Vmax = 0.8752 ± 0.13892 µmoles/ min, Km = 0.9315 ± 0.5670 µM) in comparison to control. Also, in this study the mass spectrometry analysis of Cyp A protein-peptide showed the highest sequence similarity with the cyclophilin protein of Salmonella. PPIases proteins enzyme data suggest that Ppi-A has roles in the protein folding that may be contributing to the virulence of Salmonella by isomerization of protein outline. These results suggest an active and vital role of this protein in protein folding along with regulation in Salmonella Typhimurium.


2020 ◽  
Author(s):  
Jing Xu ◽  
Yu Gu ◽  
Xinyan Yu ◽  
Ruiyang Zhang ◽  
Xuesen Zhang ◽  
...  

Abstract BackgroundPhage therapy has regained more attention due to the rise of multidrug-resistant (MDR) bacteria. Several case reports demonstrated clinical application of phage in resolving infections caused by MDR bacteria in recent years. ResultsWe isolated a new phage, vB_ShiP-A7, and then investigated its characteristics. Phage vB_ShiP-A7 is a member of Podoviridae that has an icosahedral spherical head and a short tail. vB_ShiP-A7 has large burst size and short replication time. vB_ShiP-A7’s genome is linear double stranded DNA composed of 40058 bp, encoding forty-three putative open reading frames. Comparative genome analysis demonstrated vB_ShiP-A7’s genome sequence is closely related to fifteen different phages (coverage 74-88%, identity 86-93%). Mass Spectrometry analysis revealed that twelve known proteins and six hypothetical proteins exist in particles of vB_ShiP-A7. Genome and proteome analyses confirmed the absence of lysogen-related proteins and toxic proteins in this phage. In addition, phage vB_ShiP-A7 can significantly reduce the growth of clinical MDR stains of Shigella flexneri and Escherichia coli in liquid culture. Furthermore, vB_ShiP-A7 can disrupt biofilms formed by Shigella flexneri or Escherichia coli in vitro. ConclusionPhage vB_ShiP-A7 is a stable novel phage, which has a strong application potential to inhibit MDR stains of Shigella flexneri and Escherichia coli. Comparing the genomes between vB_ShiP-A7 and other closely-related phages will help us better understand the evolutionary mechanism of phages.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Katarzyna Kozłowicz ◽  
Renata Różyło ◽  
Bożena Gładyszewska ◽  
Arkadiusz Matwijczuk ◽  
Grzegorz Gładyszewski ◽  
...  

Abstract This work aimed at the chemical and structural characterization of powders obtained from chestnut flower honey (HFCh) and honey with Inca berry (HBlu). Honey powders were obtained by spray drying technique at low temperature (80/50 °C) with dehumidified air. Maltodextrin (DE 15) was used as a covering agent. The isolation and evaluation of phenolic compounds and sugars were done by gas chromatography–mass spectrometry analysis. Scanning electron microscopy, Fourier-transform infrared (FTIR) spectroscopy, and X-ray diffraction were performed to determine the morphology of the studied honey powders. The obtained results showed that the content of simple sugars amounted to 72.4 and 90.2 g × 100 g−1 in HFCh and HBlu, respectively. Glucose was found to be the dominant sugar with a concentration of 41.3 and 51.6 g × 100 g−1 in HFCh and HBlu, respectively. 3-Phenyllactic acid and ferulic acid were most frequently found in HFCh powder, whereas m-coumaric acid, benzoic acid, and cinnamic acid were the most common in HBlu powder. The largest changes in the FTIR spectra occurred in the following range of wavenumbers: 3335, 1640, and below 930 cm−1. The X-ray diffraction profiles revealed wide peaks, suggesting that both honey powders are amorphous and are characterized by a short-range order only.


2012 ◽  
Vol 58 (8) ◽  
pp. 1027-1034 ◽  
Author(s):  
Chrystal L. Berry ◽  
Ann Karen C. Brassinga ◽  
Lynda J. Donald ◽  
W.G. Dilantha Fernando ◽  
Peter C. Loewen ◽  
...  

Pseudomonas sp. strain DF41 produces a lipopeptide, called sclerosin that inhibits the fungal pathogen Sclerotinia sclerotiorum . The aim of the current study was to deduce the chemical structure of this lipopeptide and further characterize its bioactivity. Mass spectrometry analysis determined the structure of sclerosin to be CH3-(CH2)6-CH(OH)-CH2-CO-Dhb-Pro-Ala-Leu/Ile-Ala-Val-Val-Dhb-Thr-Val-Leu/Ile-Dhp-Ala-Ala-Ala-Val-Dhb-Dhb-Ala-Dab-Ser-Val-OH, similar to corpeptins A and B of the tolaasin group, differing by only 3 amino acids in the peptide chain. Subjecting sclerosin to various ring opening procedures revealed no new ions, suggesting that this molecule is linear. As such, sclerosin represents a new member of the tolaasin lipopeptide group. Incubation of S. sclerotinia ascospores and sclerotia in the presence of sclerosin inhibited the germination of both cell types. Sclerosin also exhibited antimicrobial activity against Bacillus species. Conversely, this lipopeptide demonstrated no zoosporicidal activity against the oomycete pathogen Phytophthora infestans . Next, we assessed the effect of DF41 and a lipopeptide-deficient mutant on the growth and development of Caenorhabditis elegans larvae. We discovered that sclerosin did not protect DF41 from ingestion by and degradation in the C. elegans digestive tract. However, another metabolite produced by this bacterium appeared to shorten the life-span of the nematode compared to C. elegans growing on Escherichia coli OP50.


2019 ◽  
Vol 85 (13) ◽  
Author(s):  
Hongming Zhang ◽  
Bettina A. Buttaro ◽  
Derrick E. Fouts ◽  
Salar Sanjari ◽  
Bradley S. Evans ◽  
...  

ABSTRACTϕEf11 is a temperateSiphoviridaebacteriophage that infects strains ofEnterococcus faecalis. The ϕEf11 genome, encompassing 65 open reading frames (ORFs), is contained within 42,822 bp of DNA. Within this genome, a module of six lysis-related genes was identified. Based upon sequence homology, one of these six genes, ORF28, was predicted to code for anN-acetylmuramoyl-l-alanine amidase endolysin of 46.133 kDa, composed of 421 amino acids. The PCR-amplified ORF28 was cloned and expressed, and the resulting gene product was affinity purified to homogeneity. The purified protein was obtained from a fusion protein that exhibited a molecular mass of 72.5 kDa, consistent with a 46.1-kDa protein combined with a fused 26.5-kDa glutathioneS-transferase tag. It produced rapid, profound lysis inE. faecalispopulations and was active against 73 of 103 (71%)E. faecalisstrains tested. In addition, it caused substantial destruction ofE. faecalisbiofilms. The lysin was quite stable, retaining its activity for three years in refrigerated storage, was stable over a wide range of pHs, and was unaffected by the presence of a reducing agent; however, it was inhibited by increasing concentrations of Ca2+. Liquid chromatography-mass spectrometry analysis ofE. faecaliscell wall digestion products produced by the ORF28 endolysin indicated that the lysin acted as anN-acetylmuramidase, an endo-β-N-acetylglucosaminidase, and an endopeptidase, rather than anN-acetylmuramoyl-l-alanine amidase. The ϕEf11 ORF28 lysin shared 10% to 37% amino acid identity with the lytic enzymes of all other characterizedE. faecalisbacteriophages.IMPORTANCEThe emergence of multidrug-resistant pathogenic microorganisms has brought increasing attention to the urgent need for the development of alternative antimicrobial strategies. One such alternative to conventional antibiotics employs lytic enzymes (endolysins) that are produced by bacteriophages in the course of lytic infection. During lytic infection by a bacteriophage, these enzymes hydrolyze the cell wall peptidoglycan, resulting in the lysis of the host cell. However, external endolysin application can result in lysis from without. In this study, we have cloned, expressed, purified, and characterized an endolysin produced by a bacteriophage infecting strains ofEnterococcus faecalis. The lysin is broadly active against most of the testedE. faecalisstrains and exhibits multifunctional enzymatic specificities that differ from all other characterized endolysins produced byE. faecalisbacteriophages.


Nanoscale ◽  
2017 ◽  
Vol 9 (46) ◽  
pp. 18359-18367 ◽  
Author(s):  
Han-Wei Chu ◽  
Ju-Yi Mao ◽  
Chia-Wen Lien ◽  
Pang-Hung Hsu ◽  
Yu-Jia Li ◽  
...  

Mass spectrometry analysis of pulse laser-induced fragmentation of carbon quantum dots allows characterization of the surface functional groups and carbon core with various heteroatom doping.


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