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  • 1
    Online Resource
    Online Resource
    Role of orf73 in the development of lambdoid bacteriophages during infection of the Escherichia coli host
    Polskie Towarzystwo Biochemiczne (Polish Biochemical Society) ; 2019
    In:  Acta Biochimica Polonica ( 2019-11-26)
    Details
    In: Acta Biochimica Polonica, Polskie Towarzystwo Biochemiczne (Polish Biochemical Society), ( 2019-11-26)
    Abstract: Shiga toxin-producing Escherichia coli (STEC) is a group of pathogenic strains responsible for human infections that result in bloody diarrhea and hemorrhagic colitis, often with severe complications. The main virulence factors of STEC are Shiga toxins encoded by stx genes located in genomes of Shiga toxin-converting bacteriophages (Stx phages). These bacterial viruses are clustered in the lambdoid bacteriophages family represented by phage λ. Here, we report that expression of orf73 from the exo-xis region of the phage genome promotes the lysogenic pathway of development of λ and Φ24B phages. We demonstrated that the mutant phages with deletions of orf73 revealed higher burst size during the lytic cycle. Moreover, survival rates of E. coli infected with mutant bacteriophages were lower relative to wild-type viruses. Additionally, orf73 deletion negatively influenced the lysogenization process of E. coli host cells. We conclude that orf73 plays an important biological role in the development of lambdoid viruses, and probably it is involved in the network of molecular mechanism of the lysis-vs.-lysogenization decision.
    Type of Medium: Online Resource
    ISSN: 1734-154X , 0001-527X
    URL: Article
    DOI: 10.18388/abp.2019_2886
    Language: Unknown
    Publisher: Polskie Towarzystwo Biochemiczne (Polish Biochemical Society)
    Publication Date: 2019
    detail.hit.zdb_id: 2086022-5
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  • 2
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    The ea22 gene of lambdoid phages: preserved prolysogenic function despite of high sequence diversity
    Springer Science and Business Media LLC ; 2020
    In:  Virus Genes Vol. 56, No. 2 ( 2020-04), p. 266-277
    Details
    In: Virus Genes, Springer Science and Business Media LLC, Vol. 56, No. 2 ( 2020-04), p. 266-277
    Abstract: The exo-xis region of lambdoid phages contains open reading frames and genes that appear to be evolutionarily important. However, this region has received little attention up to now. In this study, we provided evidence that ea22 , the largest gene of this region, favors the lysogenic pathway over the lytic pathway in contrast to other characterized exo-xis region genes including ea8.5 , orf61, orf60a , and orf63. Our assays also suggest some functional analogies between Ea22 and the phage integrase protein (Int). While it is unsurprising that Ea22 operates similarly in both λ and Stx phages, we have observed some distinctions that may arise from considerable sequence dissimilarity at the carboxy termini of each protein.
    Type of Medium: Online Resource
    ISSN: 0920-8569 , 1572-994X
    URL: Article
    DOI: 10.1007/s11262-020-01734-8
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2020
    detail.hit.zdb_id: 2011138-1
    SSG: 12
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  • 3
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    Characterization of the Bacteriophage vB_EfaS-271 Infecting Enterococcus faecalis
    MDPI AG ; 2020
    In:  International Journal of Molecular Sciences Vol. 21, No. 17 ( 2020-09-01), p. 6345-
    Details
    In: International Journal of Molecular Sciences, MDPI AG, Vol. 21, No. 17 ( 2020-09-01), p. 6345-
    Abstract: 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.
    Type of Medium: Online Resource
    ISSN: 1422-0067
    URL: Article
    DOI: 10.3390/ijms21176345
    Language: English
    Publisher: MDPI AG
    Publication Date: 2020
    detail.hit.zdb_id: 2019364-6
    SSG: 12
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  • 4
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    Phage–Bacteria Interactions in Potential Applications of Bacteriophage vB_EfaS-271 against Enterococcus faecalis
    MDPI AG ; 2021
    In:  Viruses Vol. 13, No. 2 ( 2021-02-19), p. 318-
    Details
    In: Viruses, MDPI AG, Vol. 13, No. 2 ( 2021-02-19), p. 318-
    Abstract: Phage therapy is one of main alternative option for antibiotic treatment of bacterial infections, particularly in the era of appearance of pathogenic strains revealing resistance to most or even all known antibiotics. Enterococcus faecalis is one of such pathogens causing serious human infections. In the light of high level of biodiversity of bacteriophages and specificity of phages to bacterial species or even strains, development of effective phage therapy depend, between others, on identification and characterization of a large collection of these viruses, including understanding of their interactions with host bacterial cells. Recently, isolation of molecular characterization of bacteriophage vB_EfaS-271, infecting E. faecalis strains have been reported. In this report, phage–host interactions are reported, including ability of vB_EfaS-271 to infect bacteria forming biofilms, efficiency of eliminating bacterial cells from cultures depending on multiplicity of infection (m.o.i.), toxicity of purified phage particles to mammalian cells, and efficiency of appearance of phage-resistant bacteria. The presented results indicate that vB_EfaS-271 can significantly decrease number of viable E. faecalis cells in biofilms and in liquid cultures and reveals no considerable toxicity to mammalian cells. Efficiency of formation of phage-resistant bacteria was dependent on m.o.i. and was higher when the virion-cell ratio was as high as 10 than at low (between 0.01 and 0.0001) m.o.i. values. We conclude that vB_EfaS-271 may be considered as a candidate for its further use in phage therapy.
    Type of Medium: Online Resource
    ISSN: 1999-4915
    URL: Article
    DOI: 10.3390/v13020318
    Language: English
    Publisher: MDPI AG
    Publication Date: 2021
    detail.hit.zdb_id: 2516098-9
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  • 5
    Online Resource
    Online Resource
    Roles of orf60a and orf61 in Development of Bacteriophages λ and Φ24B
    MDPI AG ; 2018
    In:  Viruses Vol. 10, No. 10 ( 2018-10-11), p. 553-
    Details
    In: Viruses, MDPI AG, Vol. 10, No. 10 ( 2018-10-11), p. 553-
    Abstract: The exo-xis region of lambdoid bacteriophage genomes contains several established and potential genes that are evolutionarily conserved, but not essential for phage propagation under laboratory conditions. Nevertheless, deletion or overexpression of either the whole exo-xis region and important regulatory elements can significantly influence the regulation of phage development. This report defines specific roles for orf60a and orf61 in bacteriophage λ and Φ24B, a specific Shiga toxin-converting phage with clinical relevance. We observed that mutant phages bearing deletions of orf60a and orf61 impaired two central aspects of phage development: the lysis-versus-lysogenization decision and prophage induction. These effects were more pronounced for phage Φ24B than for λ. Surprisingly, adsorption of phage Φ24B on Escherichia coli host cells was less efficient in the absence of either orf60a or orf61. We conclude that these open reading frames (ORFs) play important, but not essential, roles in the regulation of lambdoid phage development. Although phages can propagate without these ORFs in nutrient media, we suggest that they may be involved in the regulatory network, ensuring optimization of phage development under various environmental conditions.
    Type of Medium: Online Resource
    ISSN: 1999-4915
    URL: Article
    DOI: 10.3390/v10100553
    Language: English
    Publisher: MDPI AG
    Publication Date: 2018
    detail.hit.zdb_id: 2516098-9
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  • 6
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    Characterization of a bacteriophage, vB_Eco4M-7, that effectively infects many Escherichia coli O157 strains
    Springer Science and Business Media LLC ; 2020
    In:  Scientific Reports Vol. 10, No. 1 ( 2020-02-28)
    Details
    In: Scientific Reports, Springer Science and Business Media LLC, Vol. 10, No. 1 ( 2020-02-28)
    Abstract: The characterization of a recently isolated bacteriophage, vB_Eco4M-7, which effectively infects many, though not all, Escherichia coli O157 strains, is presented. The genome of this phage comprises double-stranded DNA, 68,084 bp in length, with a GC content of 46.2%. It contains 96 putative open reading frames (ORFs). Among them, the putative functions of only 35 ORFs were predicted (36.5%), whereas 61 ORFs (63.5%) were classified as hypothetical proteins. The genome of phage vB_Eco4M-7 does not contain genes coding for integrase, recombinase, repressors or excisionase, which are the main markers of temperate viruses. Therefore, we conclude that phage vB_Eco4M-7 should be considered a lytic virus. This was confirmed by monitoring phage lytic development by a one-step growth experiment. Moreover, the phage forms relatively small uniform plaques (1 mm diameter) with no properties of lysogenization. Electron microscopic analyses indicated that vB_Eco4M-7 belongs to the Myoviridae family. Based on mass spectrometric analyses, including the fragmentation pattern of unique peptides, 33 phage vB_Eco4M-7 proteins were assigned to annotated open reading frames. Importantly, genome analysis suggested that this E. coli phage is free of toxins and other virulence factors. In addition, a similar, previously reported but uncharacterized bacteriophage, ECML-117, was also investigated, and this phage exhibited properties similar to vB_Eco4M-7. Our results indicate that both studied phages are potential candidates for phage therapy and/or food protection against Shiga toxin-producing E. coli , as the majority of these strains belong to the O157 serotype.
    Type of Medium: Online Resource
    ISSN: 2045-2322
    URL: Article
    DOI: 10.1038/s41598-020-60568-4
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2020
    detail.hit.zdb_id: 2615211-3
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  • 7
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    Bacteriophage-Derived Depolymerases against Bacterial Biofilm
    MDPI AG ; 2021
    In:  Antibiotics Vol. 10, No. 2 ( 2021-02-10), p. 175-
    Details
    In: Antibiotics, MDPI AG, Vol. 10, No. 2 ( 2021-02-10), p. 175-
    Abstract: In addition to specific antibiotic resistance, the formation of bacterial biofilm causes another level of complications in attempts to eradicate pathogenic or harmful bacteria, including difficult penetration of drugs through biofilm structures to bacterial cells, impairment of immunological response of the host, and accumulation of various bioactive compounds (enzymes and others) affecting host physiology and changing local pH values, which further influence various biological functions. In this review article, we provide an overview on the formation of bacterial biofilm and its properties, and then we focus on the possible use of phage-derived depolymerases to combat bacterial cells included in this complex structure. On the basis of the literature review, we conclude that, although these bacteriophage-encoded enzymes may be effective in destroying specific compounds involved in the formation of biofilm, they are rarely sufficient to eradicate all bacterial cells. Nevertheless, a combined therapy, employing depolymerases together with antibiotics and/or other antibacterial agents or factors, may provide an effective approach to treat infections caused by bacteria able to form biofilms.
    Type of Medium: Online Resource
    ISSN: 2079-6382
    URL: Article
    DOI: 10.3390/antibiotics10020175
    Language: English
    Publisher: MDPI AG
    Publication Date: 2021
    detail.hit.zdb_id: 2681345-2
    SSG: 15,3
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  • 8
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    Table_2.XLSX
    Frontiers Media SA ; 2019
    In:  Frontiers in Microbiology Vol. 9 ( 2019-1-15)
    Details
    In: Frontiers in Microbiology, Frontiers Media SA, Vol. 9 ( 2019-1-15)
    Type of Medium: Online Resource
    ISSN: 1664-302X
    URL: Article
    URL: Article
    URL: Article
    DOI: 10.3389/fmicb.2018.03326
    DOI: 10.3389/fmicb.2018.03326.s001
    DOI: 10.3389/fmicb.2018.03326.s002
    Language: Unknown
    Publisher: Frontiers Media SA
    Publication Date: 2019
    detail.hit.zdb_id: 2587354-4
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  • 9
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    Synergistic Effects of Bacteriophage vB_Eco4-M7 and Selected Antibiotics on the Biofilm Formed by Shiga Toxin-Producing Escherichia coli
    MDPI AG ; 2022
    In:  Antibiotics Vol. 11, No. 6 ( 2022-05-25), p. 712-
    Details
    In: Antibiotics, MDPI AG, Vol. 11, No. 6 ( 2022-05-25), p. 712-
    Abstract: Apart from antibiotic resistance of pathogenic bacteria, the formation of biofilms is a feature that makes bacterial infections especially difficulty to treat. Shiga toxin-producing Escherichia coli (STEC) strains are dangerous pathogens, causing severe infections in humans, and capable of biofilm production. We have reported previously the identification and characterization of the vB_Eco4-M7 bacteriophage, infecting various STEC strains. It was suggested that this phage might be potentially used in phage therapy against these bacteria. Here, we tested the effects of vB_Eco4-M7 alone or in a phage cocktail with another STEC-infecting phage, and/or in a combination with different antibiotics (ciprofloxacin and rifampicin) on biofilm formed by a model STEC strain, named E. coli O157:H7 (ST2-8624). The vB_Eco4-M7 phage appeared effective in anti-biofilm action in all these experimental conditions (2–3-fold reduction of the biofilm density, and 2–3 orders of magnitude reduction of the number of bacterial cells). However, the highest efficiency in reducing a biofilm’s density and number of bacterial cells was observed when phage infection preceded antibiotic treatment (6-fold reduction of the biofilm density, and 5–6 orders of magnitude reduction of the number of bacterial cells). Previous reports indicated that the use of antibiotics to treat STEC-caused infections might be dangerous due to the induction of Shiga toxin-converting prophages from bacterial genomes under stress conditions caused by antibacterial agents. We found that ciprofloxacin was almost as efficient in inducing prophages from the E. coli O15:H7 (ST2-8624) genome as a classical inducer, mitomycin C, while no detectable prophage induction could be observed in rifampicin-treated STEC cells. Therefore, we conclude the latter antibiotic or similarly acting compounds might be candidate(s) as effective and safe drug(s) when used in combination with phage therapy to combat STEC-mediated infections.
    Type of Medium: Online Resource
    ISSN: 2079-6382
    URL: Article
    DOI: 10.3390/antibiotics11060712
    Language: English
    Publisher: MDPI AG
    Publication Date: 2022
    detail.hit.zdb_id: 2681345-2
    SSG: 15,3
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  • 10
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    DataSheet_1.pdf
    Frontiers Media SA ; 2022
    In:  Frontiers in Cellular and Infection Microbiology Vol. 12 ( 2022-8-4)
    Details
    In: Frontiers in Cellular and Infection Microbiology, Frontiers Media SA, Vol. 12 ( 2022-8-4)
    Abstract: Phage therapy is a promising alternative treatment of bacterial infections in human and animals. Nevertheless, despite the appearance of many bacterial strains resistant to antibiotics, these drugs still remain important therapeutics used in human and veterinary medicine. Although experimental phage therapy of infections caused by Salmonella enterica was described previously by many groups, those studies focused solely on effects caused by bacteriophages. Here, we compared the use of phage therapy (employing a cocktail composed of two previously isolated and characterized bacteriophages, vB_SenM-2 and vB_Sen-TO17) and antibiotics (enrofloxacin and colistin) in chickens infected experimentally with S. enterica serovar Typhimurium. We found that the efficacies of both types of therapies (i.e. the use of antibiotics and phage cocktail) were high and very similar to one another when the treatment was applied shortly (one day) after the infection. Under these conditions, S. Typhimurium was quickly eliminated from the gastrointestinal tract (GIT), to the amount not detectable by the used methods. However, later treatment (2 or 4 days after detection of S. Typhimurium in chicken feces) with the phage cocktail was significantly less effective. Bacteriophages remained in the GIT for up to 2-3 weeks, and then were absent in feces and cloaca swabs. Interestingly, both phages could be found in various organs of chickens though with a relatively low abundance. No development of resistance of S. Typhimurium to phages or antibiotics was detected during the experiment. Importantly, although antibiotics significantly changed the GIT microbiome of chickens in a long-term manner, analogous changes caused by phages were transient, and the microbiome normalized a few weeks after the treatment. In conclusion, phage therapy against S. Typhimurium infection in chickens appeared as effective as antibiotic therapy (with either enrofloxacin or colistin), and less invasive than the use the antibiotics as fewer changes in the microbiome were observed.
    Type of Medium: Online Resource
    ISSN: 2235-2988
    URL: Article
    URL: Article
    DOI: 10.3389/fcimb.2022.941867
    DOI: 10.3389/fcimb.2022.941867.s001
    Language: Unknown
    Publisher: Frontiers Media SA
    Publication Date: 2022
    detail.hit.zdb_id: 2619676-1
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