Bacteriophage sp.
Ontology highlight
ABSTRACT:
PROVIDER: PRJDB14416 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:The efficacy of bacteriophages in treating bacterial infections largely depends on the phages’ vitality, which is impaired when they are naturally released from their hosts, as well as by culture media, manufacturing processes and other insults. Here, by wrapping phage-invaded bacteria individually with a polymeric nanoscale coating to preserve the microenvironment on phage-induced bacterial lysis, we show that, compared with naturally released phages, which have severely degraded proteins in their tail, the vitality of phages isolated from polymer-coated bacteria is maintained. Such latent phages could also be better amplified, and they more efficiently bound and lysed bacteria when clearing bacterial biofilms. In mice with bacterially induced enteritis and associated arthritis, latent phages released from orally administered bacteria coated with a polymer that dissolves at neutral pH had higher bioavailability and led to substantially better therapeutic outcomes than the administration of uncoated phages.
2025-02-05 | PXD054755 | Pride
Project description:Bacteriophages (hereafter “phages”) are ubiquitous predators of bacteria in the natural world, but interest is growing in their development into antibacterial therapy as complement or replacement for antibiotics. However, bacteria have evolved a huge variety of anti-phage defense systems allowing them to resist phage lysis to a greater or lesser extent, and in pathogenic bacteria these inevitably impact phage therapy outcomes. In addition to dedicated phage defense systems, some aspects of the general stress response also impact phage susceptibility, but the details of this are not well known. In order to elucidate these factors in the opportunistic pathogen Pseudomonas aeruginosa, we used the laboratory-conditioned strain PAO1 as host for phage infection experiments as it is naturally poor in dedicated phage defense systems. Screening by transposon insertion sequencing indicated that the uncharacterized operon PA3040-PA3042 was potentially associated with resistance to lytic phages. However, we found that its primary role appeared to be in regulating biofilm formation. Its expression was highly growth-phase dependent and responsive to phage infection and cell envelope stress.
2023-10-30 | GSE246284 | GEO
Project description:Virulent bacteriophages (or phages) are viruses that specifically infect and lyse a bacterial host. When multiple phages co-infect a bacterial host, the extent of lysis, dynamics of bacteria-phage and phage-phage interactions are expected to vary. The objective of this study is to identify the factors influencing the interaction of two virulent phages with different Pseudomonas aeruginosa growth states (planktonic, an infected epithelial cell line, and biofilm) by measuring the bacterial time-kill and individual phage replication kinetics. A single administration of phages effectively reduced P. aeruginosa viability in planktonic conditions and infected human lung cell cultures, but phage-resistant variants subsequently emerged. In static biofilms, the phage combination displayed initial inhibition of biofilm dispersal, but sustained control was achieved only by combining phages and meropenem antibiotic. In contrast, adherent biofilms showed tolerance to phage and/or meropenem, suggesting a spatiotemporal variation in the phage-bacterial interaction. The kinetics of adsorption of each phage to P. aeruginosa during single- or co-administration were comparable. However, the phage with the shorter lysis time depleted bacterial resources early and selected a specific nucleotide polymorphism that conferred a competitive disadvantage and cross-resistance to the second phage. The extent and strength of this phage-phage competition and genetic loci conferring phage resistance, are, however, P. aeruginosa genotype dependent. Nevertheless, adding phages sequentially resulted in their unimpeded replication with no significant increase in bacterial host lysis. These results highlight the interrelatedness of phage-phage competition, phage resistance and specific bacterial growth state (planktonic/biofilm) in shaping the interplay among P. aeruginosa and virulent phages.
2024-07-17 | GSE271537 | GEO
Project description:Natural phages isolated from holy rivers of Kathmandu against multi-drug resistant human pathogen (Escherichia coli, Klebsiella and Salmonella) collected from hospital. Genome sequencing
| PRJNA383466 | ENA
Project description:Endolysins are peptidoglycan hydrolases produced at the end of the bacteriophage (phage) replication cycle to lyse the host cell. Gram-positive phages endolysins come in a variety of multi-modular forms that combine different catalytic domains and may have evolved to adapt to their bacterial hosts. However, the reason why phage can adopt endolysin with such complex multidomain architecture is for the moment not well understood. We used the Streptococcus dysgalactiae phage endolysin PlySK1249 as a model to study the implication of multi-domain architecture in phage-induced bacterial lysis and lysis regulation. The activity of the enzyme relied on a bacteriolytic amidase (Ami), a non-bacteriolytic L-Ala-D-Ala endopeptidase (CHAP) acting as a de-chaining enzyme and central LysM cell wall binding domain (CBD). Ami and CHAP synergized for peptidoglycan digestion and bacteriolysis in the native enzyme or when expressed individually and reunified in vitro. This cooperation could be modulated by bacterial cell wall-associated proteases, which specifically cleaved the two linkers connecting the different domains. While both catalytic domains were observed to act coordinately to optimize bacterial lysis, the CBD is expected to delay diffusion of the enzyme until proteolytic inactivation is achieved. As for certain autolysins, PlySK1249 cleavage by bacterial cell wall associated proteases might be an example of dual phage-bacterial regulation and mutual coevolution.
2021-04-15 | PXD024020 | Pride
Project description:The Escherichia coli strain Nissle 1917 (EcN) is used as a probiotic for the treatment of certain gastrointestinal diseases in several European and non-European countries. In vitro studies showed EcN to efficiently inhibit the production of Shiga toxin (Stx) by Stx producing E. coli (STEC) such as Enterohemorrhagic E. coli (EHEC). The occurrence of the latest EHEC serotype (O104:H4) responsible for the great outbreak in 2011 in Germany was due to the infection of an enteroaggregative E. coli by a Stx 2-encoding lambdoid phage turning this E. coli into a lysogenic and subsequently into a Stx producing strain. Since EHEC infected persons are not recommended to be treated with antibiotics, EcN might be an alternative medication. However, because a harmless E. coli strain might be converted into a Stx-producer after becoming host to a stx encoding prophage, we tested EcN for stx-phage genome integration. Our experiments revealed the resistance of EcN towards not only stx-phages but also against the lambda phage. This resistance was not based on the lack of or by mutated phage receptors. Rather the expression of certain genes (superinfection exclusion B (sieB) and a phage repressor (pr) gene) of a defective prophage of EcN was involved in the complete resistance of EcN to infection by the stx- and lambda phage. Obviously, EcN cannot be turned into a Stx producer. Furthermore, we observed EcN to inactivate phages and thereby to protect E. coli K-12 strains against infection by stx- as well as lambda-phages. Inactivation of lambda-phages was due to binding of lambda-phages to LamB of EcN whereas inactivation of stx-phages was caused by a thermostable protein of EcN. These properties together with its ability to inhibit Stx production make EcN a good candidate for the prevention of illness caused by EHEC and probably for the treatment of already infected people.
2018-06-14 | GSE109932 | GEO