PlyPH, a bacteriolytic enzyme with a broad pH range of activity and lytic action against Bacillus anthracis.
Ontology highlight
ABSTRACT:
SUBMITTER: Yoong P
PROVIDER: S-EPMC1428399 | biostudies-literature | 2006 Apr
REPOSITORIES: biostudies-literature
Publications
PlyPH, a bacteriolytic enzyme with a broad pH range of activity and lytic action against Bacillus anthracis.
Yoong Pauline P Schuch Raymond R Nelson Daniel D Fischetti Vincent A VA
Journal of bacteriology 20060401 7
We have cloned a lytic enzyme, PlyPH, with a specific lytic effect on Bacillus anthracis strains. PlyPH remains active between pH 4 and 10.5, and a single dose rescued a significant percentage of mice infected intraperitoneally with an attenuated B. anthracis strain. We propose PlyPH as a novel therapeutic agent. ...[more]
Similar Datasets
Project description:There continues to be a need for developing efficient and environmentally friendly treatments for Bacillus anthracis, the causative agent of anthrax. One emerging approach for inactivation of vegetative B. anthracis is the use of bacteriophage endolysins or lytic enzymes encoded by bacterial genomes (autolysins) with highly evolved specificity toward bacterium-specific peptidoglycan cell walls. In this work, we performed in silico analysis of the genome of Bacillus anthracis strain Ames, using a consensus binding domain amino acid sequence as a probe, and identified a novel lytic enzyme that we termed AmiBA2446. This enzyme exists as a homodimer, as determined by size exclusion studies. It possesses N-acetylmuramoyl-l-alanine amidase activity, as determined from liquid chromatography-mass spectrometry (LC-MS) analysis of muropeptides released due to the enzymatic digestion of peptidoglycan. Phylogenetic analysis suggested that AmiBA2446 was an autolysin of bacterial origin. We characterized the effects of enzyme concentration and phase of bacterial growth on bactericidal activity and observed close to a 5-log reduction in the viability of cells of Bacillus cereus 4342, a surrogate for B. anthracis. We further tested the bactericidal activity of AmiBA2446 against various Bacillus species and demonstrated significant activity against B. anthracis and B. cereus strains. We also demonstrated activity against B. anthracis spores after pretreatment with germinants. AmiBA2446 enzyme was also stable in solution, retaining its activity after 4 months of storage at room temperature.
| S-EPMC3811352 | biostudies-literature
Project description:The emergence of antibiotic-resistant bacteria has become a serious global health threat requiring the development of novel treatments. Klebsiella pneumoniae is an encapsulated bacterium considered a major concern due to its high resistance, prevalence, and mortality rates. Phage therapy has been proposed as a very promising alternative to combat infections by Klebsiella sp. infections. However, most of the Klebsiella phages described so far present a high specificity, infecting one or a few capsular types due to the presence of depolymerases in their genomes, which limits their therapeutic potential. Here, we present three new Klebsiella phages isolated from the environment, vB_Kpn_K7PH164C4, vB_Kpn_K30λ2.2, and vB_Kpl_K32PH164C1, belonging to the family Demerecviridae and the genus Sugarlandvirus. The most important feature of these new Klebsiella phages is their broad host range, especially vB_Kpn_K7PH164C4 and vB_Kpn_K30λ2.2, which infects strains of more than 20 different capsular types, representing the broadest infection range observed for Klebsiella phages. Genomic analysis revealed the presence of three receptor-binding proteins lacking depolymerase domains. Nevertheless, capsule expression is suggested to be a determining factor in phage infectivity, despite the absence of depolymerase activity against capsular components. Our findings hold potential for the development of promising phage-based therapeutics directed against K. pneumoniae.IMPORTANCEThe emergence of multi-drug resistant bacteria is a global health problem. Among them, Klebsiella pneumoniae is considered a high-priority pathogen, making it necessary to develop new therapeutic tools to reduce the bacterial burden in an effective and sustainable manner. Phages, bacterial viruses, are very promising tools. However, phages are highy specific, rendering large-scale therapeutics costly to implement. This is especially certain in Klebsiella, a capsular bacterium in which phages have been shown to be capsular type dependent, infecting one or a few capsular types through specific enzymes called depolymerases. In this study, we have isolated and characterized novel phages with lytic ability against bacteria from a wide variety of capsular types, representing the Klebsiella phages with the widest range of infection described. Remarkably, these broad-range phages showed capsule dependency, despite the absence of depolymerases in their genomes, implying that infectivity could be governed by alternative mechanisms yet to be uncovered.
| S-EPMC10714931 | biostudies-literature
Project description:Vibriosis is one of the most common bacterial diseases that cause high rates of mortality and considerable economic losses in aquaculture. Phage therapy has been considered as a promising alternative method to antibiotics in the biocontrol of infectious diseases. Genome sequencing and characterization of the phage candidates are prerequisites before field applications to ensure environmental safety. In this study, a lytic phage, named vB_VhaS-R18L (R18L), was isolated from the coastal seawater of Dongshan Island, China. The phage was characterized in terms of morphology, genetic content, infection kinetics, lytic profile, and virion stability. Transmission electronic microscopy indicated that R18L is siphovirus-like, comprising an icosahedral head (diameter 88.6 ± 2.2 nm) and a long noncontractile tail (225 × 11 nm). Genome analysis indicated R18L to be a double-stranded DNA virus with a genome size of 80,965 bp and a G + C content of 44.96%. No genes that encode known toxins or genes implicated in lysogeny control were found in R18L. A one-step growth experiment showed that R18L had a latent period of approximately 40 min and a burst size of 54 phage particles per infected cell. R18L showed lytic activity against a wide range of at least five Vibrio species (V. alginolyticus, V. cholerae, V. harveyi, V. parahemolyticus, and V. proteolyticus). R18L was relatively stable at pH 6-11 and at temperatures ranging from 4°C to 50°C. The broad lytic activity across Vibrio species and the stability in the environment make R18L a potential candidate for phage therapy in controlling vibriosis in aquaculture systems.
| S-EPMC10272388 | biostudies-literature
Project description:The genome sequence of a Bacillus anthracis-specific clear plaque mutant phage, AP50c, contains 31 open reading frames spanning 14,398 bp, has two mutations compared to wild-type AP50t, and has a colinear genome architecture highly similar to that of gram-positive Tectiviridae phages. Spontaneous AP50c-resistant B. anthracis mutants exhibit a mucoid colony phenotype.
| S-EPMC2576697 | biostudies-literature
Project description:BACKGROUND: Comparatively little information is available on members of the Myoviridae infecting low G+C content, Gram-positive host bacteria of the family Firmicutes. While numerous Bacillus phages have been isolated up till now only very few Bacillus cereus phages have been characterized in detail. RESULTS: Here we present data on the large, virulent, broad-host-range B. cereus phage vB_BceM_Bc431v3 (Bc431v3). Bc431v3 features a 158,618 bp dsDNA genome, encompassing 239 putative open reading frames (ORFs) and, 20 tRNA genes encoding 17 different amino acids. Since pulsed-field gel electrophoresis indicated that the genome of this phage has a mass of 155-158 kb Bc431v3 DNA appears not to contain long terminal repeats that are found in the genome of Bacillus phage SPO1. CONCLUSIONS: Bc431v3 displays significant sequence similarity, at the protein level, to B. cereus phage BCP78, Listeria phage A511 and Enterococcus phage ØEF24C and other morphologically related phages infecting Firmicutes such as Staphylococcus phage K and Lactobacillus phage LP65. Based on these data we suggest that Bc431v3 should be included as a member of the Spounavirinae; however, because of all the diverse taxonomical information has been addressed recently, it is difficult to determine the genus. The Bc431v3 phage contains some highly unusual genes such as gp143 encoding putative tRNAHis guanylyltransferase. In addition, it carries some genes that appear to be related to the host sporulation regulators. These are: gp098, which encodes a putative segregation protein related to FstK/SpoIIIE DNA transporters; gp105, a putative segregation protein; gp108, RNA polymerase sigma factor F/B; and, gp109 encoding RNA polymerase sigma factor G.
| S-EPMC3601020 | biostudies-literature
Project description:Bacillus anthracis elaborates a poly-gamma-d-glutamic acid capsule that protects bacilli from phagocytic killing during infection. The enzyme CapD generates amide bonds with peptidoglycan cross-bridges to anchor capsular material within the cell wall envelope of B. anthracis. The capsular biosynthetic pathway is essential for virulence during anthrax infections and can be targeted for anti-infective inhibition with small molecules. Here, we present the crystal structures of the gamma-glutamyltranspeptidase CapD with and without alpha-l-Glu-l-Glu dipeptide, a non-hydrolyzable analog of poly-gamma-d-glutamic acid, in the active site. Purified CapD displays transpeptidation activity in vitro, and its structure reveals an active site broadly accessible for poly-gamma-glutamate binding and processing. Using structural and biochemical information, we derive a mechanistic model for CapD catalysis whereby Pro(427), Gly(428), and Gly(429) activate the catalytic residue of the enzyme, Thr(352), and stabilize an oxyanion hole via main chain amide hydrogen bonds.
| S-EPMC2782033 | biostudies-literature
Project description:The structural characteristics of a spore enable it to withstand stresses that typically kill a vegetative cell. Spores remain dormant until small molecule signals induce them to germinate into vegetative bacilli. Germination requires degradation of the thick cortical peptidoglycan by germination-specific lytic enzymes (GSLEs). Bacillus anthracis has four putative GSLEs, based upon sequence similarities with enzymes in other species: SleB, CwlJ1, CwlJ2, and SleL. In this study, the roles of SleB, CwlJ1, and CwlJ2 were examined. The expression levels of all three genes peak 3.5 h into sporulation. Genetic analysis revealed that, similar to other known GSLEs, none of these gene products are individually required for growth, sporulation, or triggering of germination. However, later germination events are affected in spores lacking CwlJ1 or SleB. Compared to the wild type, germinating spores without CwlJ1 suffer a delay in optical density loss and cortex peptidoglycan release. The absence of SleB also causes a delay in cortex fragment release. A double mutant lacking both SleB and CwlJ1 is completely blocked in cortex hydrolysis and progresses through outgrowth to produce colonies at a frequency 1,000-fold lower than that of the wild-type strain. A null mutation eliminating CwlJ2 has no effect on germination. High-performance liquid chromatography and mass spectroscopy analysis revealed that SleB is required for lytic transglycosylase activity. CwlJ1 also clearly participates in cortex hydrolysis, but its specific mode of action remains unclear. Understanding the lytic germination activities that naturally diminish spore resistance can lead to methods for prematurely inducing them, thus simplifying the process of treating contaminated sites.
| S-EPMC2655533 | biostudies-literature
Project description:The poly-γ-d-glutamic acid capsule of Bacillus anthracis is a barrier to infection by B. anthracis-specific bacteriophages. Capsule expression was found to completely inhibit lytic infection by γ phage, an observation supported by the demonstration that this phage does not elaborate a hydrolase that would facilitate penetration through the protective capsule outer layer.
| S-EPMC3553781 | biostudies-literature
Project description:Staphylococcus aureus is a very successful opportunistic pathogen capable of causing a variety of diseases ranging from mild skin infections to life-threatening sepsis, meningitis and pneumonia. Its ability to display numerous virulence mechanisms matches its skill to display resistance to several antibiotics, including β-lactams, underscoring the fact that new anti-S. aureus drugs are urgently required. In this scenario, the utilization of lytic bacteriophages that kill bacteria in a genus -or even species- specific way, has become an attractive field of study. In this report, we describe the isolation, characterization and sequencing of phages capable of killing S. aureus including methicillin resistant (MRSA) and multi-drug resistant S. aureus local strains from environmental, animal and human origin. Genome sequencing and bio-informatics analysis showed the absence of genes encoding virulence factors, toxins or antibiotic resistance determinants. Of note, there was a high similarity between our set of phages to others described in the literature such as phage K. Considering that reported phages were obtained in different continents, it seems plausible that there is a commonality of genetic features that are needed for optimum, broad host range anti-staphylococcal activity of these related phages. Importantly, the high activity and broad host range of one of our phages underscores its promising value to control the presence of S. aureus in fomites, industry and hospital environments and eventually on animal and human skin. The development of a cocktail of the reported lytic phages active against S. aureus-currently under way- is thus, a sensible strategy against this pathogen.
| S-EPMC5526547 | biostudies-literature
Project description:Anthrax lethal toxin directly targets human peripheral monocytes and causes multiple aberrant gene responses that would be expected to result in defects in human monocyte’s normal signaling transduction pathways and nction. This study provides further insights into the mechanisms associated with the host immune system collapse during an anthrax infection, and suggests that anthrax LT may have additional targets outside the well-known MAPK pathway.
2012-12-12 | GSE34407 | GEO