Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Characterization of lytic activity of Phage SAvB14 on Staphylococcus aureus variant bovis

ABSTRACT: Objective: The objective of this study was to investigate the intensity of phage infection caused by Phage SAvB14, which was isolated from dairy farms, depending on the initial number of Staphylococcus aureus cells in the medium. Material and methods: To evaluate the impact of the viable bacteria S. aureus var. bovis on the intensity of phage infection caused by Phage SAvB14, 1 mg of phagolysate (phage titer 105 CFU/ ml) was introduced in 9 ml of nutrient broth with an appropriate amount of daily culture of S. aureus var. bovis under study. The number of viable staphylococci was determined by total viable count/ml. Results: In this experiment, we found that the intensity of phages lytic activity was dependent on the number of sensitive bacterial cells in the volume of the culture medium. Effective phage therapy requires a high concentration of phages in the medium (inflammation foci) for rapid contact of the virus with bacteria. Conclusion: When developing a phage drug to treat subclinical mastitis, it is necessary to increase the phage titer in the drug or its dosage compared to the clinical form, as there is a lower probability of phage contact with a susceptible microbial cell. Besides, at a high concentration of bacteria, there is a gradual decrease in nutrients in the medium, resulting in phages going back to the condition of lysogeny.

SUBMITTER: Horiuk Y

PROVIDER: S-EPMC7521818 | biostudies-literature | 2020 Aug

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Isolation and Characterization of a Lytic Staphylococcus aureus Phage WV against Staphylococcus aureus Biofilm.

Project description:BackgroundStaphylococcus aureus is a Gram-positive, pathogenic bacterium that causes a wide range of symptoms in humans and can form biofilm, which is a multicellular community of microorganisms that attaches to nonbiological and biological surfaces.MethodsHere, we aimed to isolate and characterize an S. aureus phage and examine the bactericidal activity alone and in conjunction with streptomycin treatment.ResultsWe isolated a virulent phage, WV, from a slaughterhouse in Jiangsu, China. This strain belonged to the family Myoviridae and presented a genome size of 141,342 bp. The optimal pH of the preservation buffer was 6-7, optimal growth temperature was 37°C, and optimal multiplicity of infection was 0.01. Phage WV can sterilize most clinical strains of S. aureus that had been isolated from clinical patients in the First People's Hospital of the Yunnan Province. Against low-concentration S. aureus culture, streptomycin demonstrated a greater antibiofilm effect than that of phage WV. By contrast, in high-concentration S. aureus culture, phage WV demonstrated greater antibiofilm effect than that of streptomycin. The use of phage WV and streptomycin together had a substantially greater overall antibiofilm effect than that achieved using either component alone.ConclusionThis study provides strong evidence for the effectiveness of phage application for the reduction of S. aureus biofilm growth and suggests that phages can be considered as a viable alternative to antibiotics in clinical settings.

| S-EPMC8619764 | biostudies-literature

Are Phage Lytic Proteins the Secret Weapon To Kill Staphylococcus aureus?

Project description:Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most threatening microorganisms for global human health. The current strategies to reduce the impact of S. aureus include a restrictive control of worldwide antibiotic use, prophylactic measures to hinder contamination, and the search for novel antimicrobials to treat human and animal infections caused by this bacterium. The last strategy is currently the focus of considerable research. In this regard, phage lytic proteins (endolysins and virion-associated peptidoglycan hydrolases [VAPGHs]) have been proposed as suitable candidates. Indeed, these proteins display narrow-spectrum antimicrobial activity and a virtual lack of bacterial-resistance development. Additionally, the therapeutic use of phage lytic proteins in S. aureus animal infection models is yielding promising results, showing good efficacy without apparent side effects. Nonetheless, human clinical trials are still in progress, and data are not available yet. This minireview also analyzes the main obstacles for introducing phage lytic proteins as human therapeutics against S. aureus infections. Besides the common technological problems derived from large-scale production of therapeutic proteins, a major setback is the lack of a proper legal framework regulating their use. In that sense, the relevant health authorities should urgently have a timely discussion about these new antimicrobials. On the other hand, the research community should provide data to dispel any doubts regarding their efficacy and safety. Overall, the appropriate scientific data and regulatory framework will encourage pharmaceutical companies to invest in these promising antimicrobials.

| S-EPMC5784253 | biostudies-literature

Expression and lytic efficacy assessment of the Staphylococcus aureus phage SA4 lysin gene.

Project description:Treatment of bovine mastitis caused by Staphylococcus (S.) aureus is becoming very difficult due to the emergence of multidrug-resistant strains. Hence, the search for novel therapeutic alternatives has become of great importance. Consequently, bacteriophages and their endolysins have been identified as potential therapeutic alternatives to antibiotic therapy against S. aureus. In the present study, the gene encoding lysin (LysSA4) in S. aureus phage SA4 was cloned and the nucleotide sequence was determined. Sequence analysis of the recombinant clone revealed a single 802-bp open reading frame encoding a artial protein with a calculated mass of 30 kDa. Results of this analysis also indicated that the LysSA4 sequence shared a high homology with endolysin of the GH15 phage and other reported phages. The LysSA4 gene of the SA4 phage was subsequently expressed in Escherichia coli. Recombinant LysSA4 induced the lysis of host bacteria in a spot inoculation test, indicating that the protein was expressed and functionally active. Furthermore, recombinant lysin was found to have lytic activity, albeit a low level, against mastitogenic Staphylococcus isolates of bovine origin. Data from the current study can be used to develop therapeutic tools for treating diseases caused by drug-resistant S. aureus strains.

| S-EPMC3615230 | biostudies-literature

Characterization of novel <i>Staphylococcus aureus</i> lytic phage and defining their combinatorial virulence using the OmniLog® system.

Project description:Skin and soft tissue infections (SSTI) caused by methicillin resistant Staphylococcus aureus (MRSA) are difficult to treat. Bacteriophage (phage) represent a potential alternate treatment for antibiotic resistant bacterial infections. In this study, 7 novel phage with broad lytic activity for S. aureus were isolated and identified. Screening of a diverse collection of 170 clinical isolates by efficiency of plating (EOP) assays shows that the novel phage are virulent and effectively prevent growth of 70-91% of MRSA and methicillin sensitive S. aureus (MSSA) isolates. Phage K, which was previously identified as having lytic activity on S. aureus was tested on the S. aureus collection and shown to prevent growth of 82% of the isolates. These novel phage group were examined by electron microscopy, the results of which indicate that the phage belong to the Myoviridae family of viruses. The novel phage group requires ?-N-acetyl glucosamine (GlcNac) moieties on cell wall teichoic acids for infection. The phage were distinct from, but closely related to, phage K as characterized by restriction endonuclease analysis. Furthermore, growth rate analysis via OmniLog® microplate assay indicates that a combination of phage K, with phage SA0420?1, SA0456?1 or SA0482?1 have a synergistic phage-mediated lytic effect on MRSA and suppress formation of phage resistance. These results indicate that a broad spectrum lytic phage mixture can suppress the emergence of resistant bacterial populations and hence have great potential for combating S. aureus wound infections.

| S-EPMC5056778 | biostudies-literature

Characterization of the Three New Kayviruses and Their Lytic Activity Against Multidrug-Resistant Staphylococcus aureus.

Project description:The development of antimicrobial resistance has become a global concern. One approach to overcome the problem of drug resistance is the application of bacteriophages. This study aimed at characterizing three phages isolated from sewage, which show lytic activity against clinical isolates of multidrug-resistant Staphylococcus aureus. Morphology, genetics and biological properties, including host range, adsorption rate, latent time, phage burst size and lysis profiles, were studied in all three phages. As analyzed by transmission electron microscopy (TEM), phages vB_SauM-A, vB_SauM-C, vB_SauM-D have a myovirion morphology. One of the tested phages, vB_SauM-A, has relatively rapid adsorption (86% in 17.5 min), short latent period (25 min) and extremely large burst size (~500 plaque-forming units (PFU) per infected cell). The genomic analysis revealed that vB_SauM-A, vB_SauM-C, vB_SauM-D possess large genomes (vB_SauM-A 139,031 bp, vB_SauM-C 140,086 bp, vB_SauM-D 139,088 bp) with low G+C content (~30.4%) and are very closely related to the phage K (95-97% similarity). The isolated bacteriophages demonstrate broad host range against MDR S. aureus strains, high lytic activity corresponding to strictly virulent life cycle, suggesting their potential to treat S. aureus infections.

| S-EPMC6843549 | biostudies-literature

Staphylococcal phage 2638A endolysin is lytic for Staphylococcus aureus and harbors an inter-lytic-domain secondary translational start site.

Project description:Staphylococcus aureus is a notorious pathogen highly successful at developing resistance to virtually all antibiotics to which it is exposed. Staphylococcal phage 2638A endolysin is a peptidoglycan hydrolase that is lytic for S. aureus when exposed externally, making it a new candidate antimicrobial. It shares a common protein organization with more than 40 other reported staphylococcal peptidoglycan hydrolases. There is an N-terminal M23 peptidase domain, a mid-protein amidase 2 domain (N-acetylmuramoyl-L-alanine amidase), and a C-terminal SH3b cell wall-binding domain. It is the first phage endolysin reported with a secondary translational start site in the inter-lytic-domain region between the peptidase and amidase domains. Deletion analysis indicates that the amidase domain confers most of the lytic activity and requires the full SH3b domain for maximal activity. Although it is common for one domain to demonstrate a dominant activity over the other, the 2638A endolysin is the first in this class of proteins to have a high-activity amidase domain (dominant over the N-terminal peptidase domain). The high activity amidase domain is an important finding in the quest for high-activity staphylolytic domains targeting novel peptidoglycan bonds.

| S-EPMC3730814 | biostudies-literature

Downregulation of autolysin-encoding genes by phage-derived lytic proteins inhibits biofilm formation in Staphylococcus aureus

Project description:Phage-derived lytic proteins are a promising alternative to conventional antimicrobials. One of their most interesting properties is that they do not readily select for resistant strains, which is likely due to the fact that their targets are essential for the viability of the bacterial cell. Moreover, genetic engineering allows the design of new "tailor-made" proteins that may exhibit improved antibacterial properties. One example of this is the chimeric protein CHAPSH3b, which consists of a catalytic domain from the virion-associated peptidoglycan (PG) hydrolase of phage vB_SauS-phiIPLA88 (HydH5) and the cell wall binding domain of lysostaphin. CHAPSH3b had previously shown the ability to kill S. aureus cells. Here, we demonstrate that this lytic protein also has potential for the control of biofilm-embedded S. aureus cells. Additionally, subinhibitory doses of CHAPSH3b can decrease biofilm formation by some S. aureus strains. Transcriptional analysis revealed that exposure of S. aureus cells to this enzyme leads to the downregulation of several genes coding for bacterial autolysins. One of these proteins, namely the major autolysin AtlA, is known to participate in staphylococcal biofilm development. Interestingly, an atl mutant strain did not display inhibition of biofilm development when grown at subinhibitory concentrations of CHAPSH3b, contrary to the observations made for the parental and complemented strains. Also, deletion of atl led to low-level resistance to CHAPSH3b and endolysin LysH5. Overall, our results reveal new aspects that should be considered when designing new phage-derived lytic proteins aimed for antimicrobial applications.

2017-03-16 | GSE94512 | GEO

Downregulation of Autolysin-Encoding Genes by Phage-Derived Lytic Proteins Inhibits Biofilm Formation in Staphylococcus aureus.

Project description:Phage-derived lytic proteins are a promising alternative to conventional antimicrobials. One of their most interesting properties is that they do not readily select for resistant strains, which is likely due to the fact that their targets are essential for the viability of the bacterial cell. Moreover, genetic engineering allows the design of new "tailor-made" proteins that may exhibit improved antibacterial properties. One example of this is the chimeric protein CHAPSH3b, which consists of a catalytic domain from the virion-associated peptidoglycan hydrolase of phage vB_SauS-phiIPLA88 (HydH5) and the cell wall binding domain of lysostaphin. CHAPSH3b had previously shown the ability to kill Staphylococcus aureus cells. Here, we demonstrate that this lytic protein also has potential for the control of biofilm-embedded S. aureus cells. Additionally, subinhibitory doses of CHAPSH3b can decrease biofilm formation by some S. aureus strains. Transcriptional analysis revealed that exposure of S. aureus cells to this enzyme leads to the downregulation of several genes coding for bacterial autolysins. One of these proteins, namely, the major autolysin AtlA, is known to participate in staphylococcal biofilm development. Interestingly, an atl mutant strain did not display inhibition of biofilm development when grown at subinhibitory concentrations of CHAPSH3b, contrary to the observations made for the parental and complemented strains. Also, deletion of atl led to low-level resistance to CHAPSH3b and the endolysin LysH5. Overall, our results reveal new aspects that should be considered when designing new phage-derived lytic proteins aimed for antimicrobial applications.

| S-EPMC5404533 | biostudies-literature

Synergistic action of phage phiIPLA-RODI and lytic protein CHAPSH3b: a combination strategy to target Staphylococcus aureus biofilms.

Project description:Staphylococcus aureus is considered a priority pathogen due to its increasing acquisition of antibiotic resistance determinants. Additionally, this microbe has the ability to form recalcitrant biofilms on different biotic and inert surfaces. In this context, bacteriophages and their derived lytic proteins may be a forward-looking strategy to help combat staphylococcal biofilms. However, these antimicrobials exhibit individual limitations that may be overcome by combining them with other compounds. This work investigates the combination of a phage-derived lytic protein, CHAPSH3b, and the virulent bacteriophage phiIPLA-RODI. The obtained results show the synergy between both antimicrobials for the treatment of 24-h-old S. aureus biofilms, with greater reductions in viable cell counts observed when phage and lysin are applied together compared to the individual treatments. Time-kill curves and confocal microscopy revealed that the fast antibacterial action of CHAPSH3b reduces the population up to 7 hours after initial exposure, which is subsequently followed by phage predation, limiting regrowth of the bacterial population. Moreover, at least 90% of bacteriophage insensitive mutants are susceptible to the lytic protein. Therefore, CHAPSH3b might help curtail the development of phage resistance during treatment. The combination of the lysin and phiIPLA-RODI also showed promising results in an ex vivo pig skin model of wound infection. Overall, the results of this study demonstrate that the combination of phage-derived lytic proteins and bacteriophages can be a viable strategy to develop improved antibiofilm products.

| S-EPMC8062563 | biostudies-literature

Efficacy of Lytic Phage Cocktails on Staphylococcus aureus and Pseudomonas aeruginosa in Mixed-Species Planktonic Cultures and Biofilms.

Project description:The efficacy of phages in multispecies infections has been poorly examined. The in vitro lytic efficacies of phage cocktails AB-SA01, AB-PA01, which target Staphylococcus aureus and Pseudomonas aeruginosa, respectively, and their combination against their hosts were evaluated in S. aureus and P. aeruginosa mixed-species planktonic and biofilm cultures. Green fluorescent protein (GFP)-labelled P. aeruginosa PAO1 and mCherry-labelled S. aureus KUB7 laboratory strains and clinical isolates were used as target bacteria. During real-time monitoring using fluorescence spectrophotometry, the density of mCherry S. aureus KUB7 and GFP P. aeruginosa PAO1 significantly decreased when treated by their respective phage cocktail, a mixture of phage cocktails, and gentamicin. The decrease in bacterial density measured by relative fluorescence strongly associated with the decline in bacterial cell counts. This microplate-based mixed-species culture treatment monitoring through spectrophotometry combine reproducibility, rapidity, and ease of management. It is amenable to high-throughput screening for phage cocktail efficacy evaluation. Each phage cocktail, the combination of the two phage cocktails, and tetracycline produced significant biofilm biomass reduction in mixed-species biofilms. This study result shows that these phage cocktails lyse their hosts in the presence of non-susceptible bacteria. These data support the use of phage cocktails therapy in infections with multiple bacterial species.

| S-EPMC7291191 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data