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Scholl, Dean. "Phage Tail–Like Bacteriocins." Annual Review of Virology 4, no. 1 (2017): 453–67. http://dx.doi.org/10.1146/annurev-virology-101416-041632.
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Lee, Grace, Urmi Chakraborty, Dana Gebhart, Gregory R. Govoni, Z. Hong Zhou, and Dean Scholl. "F-Type Bacteriocins of Listeria monocytogenes: a New Class of Phage Tail-Like Structures Reveals Broad Parallel Coevolution between Tailed Bacteriophages and High-Molecular-Weight Bacteriocins." Journal of Bacteriology 198, no. 20 (2016): 2784–93. http://dx.doi.org/10.1128/jb.00489-16.
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ABSTRACTListeria monocytogenesis a significant foodborne human pathogen that can cause severe disease in certain high-risk individuals.L. monocytogenesis known to produce high-molecular-weight, phage tail-like bacteriocins, or “monocins,” upon induction of the SOS system. In this work, we purified and characterized monocins and found them to be a new class of F-type bacteriocins. TheL. monocytogenesmonocin genetic locus was cloned and expressed inBacillus subtilis, producing specifically targeted bactericidal particles. The receptor binding protein, which determines target cell specificity, was identified and engineered to change the bactericidal spectrum. Unlike the F-type pyocins ofPseudomonas aeruginosa, which are related to lambda-like phage tails, monocins are more closely related to TP901-1-like phage tails, structures not previously known to function as bacteriocins. Monocins therefore represent a new class of phage tail-like bacteriocins. It appears that multiple classes of phage tails and their related bacteriocins have coevolved separately in parallel.IMPORTANCEPhage tail-like bacteriocins (PTLBs) are structures widespread among the members of the bacterial kingdom that are evolutionarily related to the DNA delivery organelles of phages (tails). We identified and characterized “monocins” ofListeria monocytogenesand showed that they are related to the tail structures of TP901-1-like phages, structures not previously known to function as bacteriocins. Our results show that multiple types of envelope-penetrating machines have coevolved in parallel to function either for DNA delivery (phages) or as membrane-disrupting bacteriocins. While it has commonly been assumed that these structures were coopted from phages, we cannot rule out the opposite possibility, that ancient phages coopted complex bacteriocins from the cell, which then underwent adaptations to become efficient at translocating DNA.
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Šmarda, Jan, and Oldřich Benada. "Phage Tail-Like (High-Molecular-Weight) Bacteriocins of Budvicia aquatica and Pragia fontium (Enterobacteriaceae)." Applied and Environmental Microbiology 71, no. 12 (2005): 8970–73. http://dx.doi.org/10.1128/aem.71.12.8970-8973.2005.
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ABSTRACT Electron microscopic analysis of contractile phage tail-like bacteriocins of three Pragia fontium strains and one Budvicia aquatica strain was performed. Fonticin and aquaticin are remarkably heat sensitive but trypsin resistant. Simultaneous production of contractile and flexible phage tail-like bacteriocins in the P. fontium 64613 strain is shown for the first time.
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Dams, Dorien, Lone Brøndsted, Zuzanna Drulis-Kawa, and Yves Briers. "Engineering of receptor-binding proteins in bacteriophages and phage tail-like bacteriocins." Biochemical Society Transactions 47, no. 1 (2019): 449–60. http://dx.doi.org/10.1042/bst20180172.
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AbstractBacteriophages and phage tail-like bacteriocins (PTLBs) rely on receptor-binding proteins (RBPs) located in tail fibers or spikes for an initial and specific interaction with susceptible bacteria. Bacteriophages kill bacteria through a lytic, replicative cycle, whereas PTLBs kill the target through membrane depolarization in a single hit mechanism. Extensive efforts in the engineering of RBPs of both phages and PTLBs have been undertaken to obtain a greater understanding of the structural organization of RBPs. In addition, a major goal of engineering RBPs of phages and PTLBs is the production of antibacterials with a customized spectrum. Swapping of the RBP of phages and PTLBs results in a shift in activity spectrum in accordance with the spectrum of the new RBP. The engineering of strictly virulent phages with new RBPs required significant technical advances in the past decades, whereas the engineering of RBPs of PTLBs relied on the traditional molecular techniques used for the manipulation of bacteria and was thus relatively straightforward. While phages and PTLBs share their potential for specificity tuning, specific features of phages such as their lytic killing mechanism, their self-replicative nature and thus different pharmacokinetics and their potential to co-evolve are clear differentiators compared with PTLBs in terms of their antibacterial use.
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Lee, Sangmi. "Bacteriocins of Listeria monocytogenes and Their Potential as a Virulence Factor." Toxins 12, no. 2 (2020): 103. http://dx.doi.org/10.3390/toxins12020103.
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Intestinal microbiota exerts protective effects against the infection of various bacterial pathogens, including Listeria monocytogenes, a major foodborne pathogen whose infection can lead to a disease (listeriosis) with a high fatality rate. As a strategy to mitigate the action of the intestinal microbiota, pathogens often produce antimicrobial proteinaceous compounds such as bacteriocins. In this review, we summarize the information currently available for the well-characterized L. monocytogenes bacteriocin listeriolysin S, with the emphasis on its intriguing mode of action as a virulence factor, which promotes the infection of L. monocytogenes by changing the composition of the intestinal microbiota. We then discuss another intriguing L. monocytogenes bacteriocin Lmo2776 that specifically inhibits the inflammogenic species, Prevotella copri, in the intestinal microbiota, reducing superfluous inflammation while weakening virulence. In addition, we describe relatively less studied phage tail-like Listeria bacteriocins (monocins) and elaborate on the possibility that these monocins could be involved in enhancing pathogenicity. In spite of the burgeoning interest in the roles played by the intestinal microbiota against the L. monocytogenes infection, our understanding on the virulence factors affecting the intestinal microbiota is still lacking, calling for further studies on bacteriocins that could function as novel virulence factors.
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Babar, Tauseef K., Travis R. Glare, John G. Hampton, Mark R. H. Hurst, and Josefina O. Narciso. "Isolation, Purification, and Characterisation of a Phage Tail-Like Bacteriocin from the Insect Pathogenic Bacterium Brevibacillus laterosporus." Biomolecules 12, no. 8 (2022): 1154. http://dx.doi.org/10.3390/biom12081154.
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The Gram-positive and spore-forming bacterium Brevibacillus laterosporus (Bl) belongs to the Brevibacillus brevis phylogenetic cluster. Isolates of the species have demonstrated pesticidal potency against a wide range of invertebrate pests and plant diseases. Two New Zealand isolates, Bl 1821L and Bl 1951, are under development as biopesticides for control of diamondback moth and other pests. However, due to the often-restricted growth of these endemic isolates, production can be an issue. Based on the previous work, it was hypothesised that the putative phages might be involved. During investigations of the cause of the disrupted growth, electron micrographs of crude lysate of Bl 1821L showed the presence of phages’ tail-like structures. A soft agar overlay method with PEG 8000 precipitation was used to differentiate between the antagonistic activity of the putative phage and phage tail-like structures (bacteriocins). Assay tests authenticated the absence of putative phage activity. Using the same method, broad-spectrum antibacterial activity of Bl 1821L lysate against several Gram-positive bacteria was found. SDS-PAGE of sucrose density gradient purified and 10 kD MWCO concentrated lysate showed a prominent protein band of ~48 kD, and transmission electron microscopy revealed the presence of polysheath-like structures. N-terminal sequencing of the ~48 kD protein mapped to a gene with weak predicted amino acid homology to a Bacillus PBSX phage-like element xkdK, the translated product of which shared >90% amino acid similarity to the phage tail-sheath protein of another Bl published genome, LMG15441. Bioinformatic analysis also identified an xkdK homolog in the Bl 1951 genome. However, genome comparison of the region around the xkdK gene between Bl 1821L and Bl 1951 found differences including two glycine rich protein encoding genes which contain imperfect repeats (1700 bp) in Bl 1951, while a putative phage region resides in the analogous Bl 1821L region. Although comparative analysis of the genomic organisation of Bl 1821L and Bl 1951 PBSX-like region with the defective phages PBSX, PBSZ, and PBP 180 of Bacillus subtilis isolates 168 and W23, and Bacillus phage PBP180 revealed low amino acids similarity, the genes encode similar functional proteins in similar arrangements, including phage tail-sheath (XkdK), tail (XkdO), holin (XhlB), and N-acetylmuramoyl-l-alanine (XlyA). AMPA analysis identified a bactericidal stretch of 13 amino acids in the ~48 kD sequenced protein of Bl 1821L. Antagonistic activity of the purified ~48 kD phage tail-like protein in the assays differed remarkably from the crude lysate by causing a decrease of 34.2% in the number of viable cells of Bl 1951, 18 h after treatment as compared to the control. Overall, the identified inducible phage tail-like particle is likely to have implications for the in vitro growth of the insect pathogenic isolate Bl 1821L.
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Bhattacharjee, Rahul, Aditya Nandi, Adrija Sinha, et al. "Phage-tail-like bacteriocins as a biomedical platform to counter anti-microbial resistant pathogens." Biomedicine & Pharmacotherapy 155 (November 2022): 113720. http://dx.doi.org/10.1016/j.biopha.2022.113720.
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Ibarguren, Clara, Inés Bleriot, Lucia Blasco, et al. "The world of phage tail-like bacteriocins: State of the art and biotechnological perspectives." Microbiological Research 295 (June 2025): 128121. https://doi.org/10.1016/j.micres.2025.128121.
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Lee, Frank K. N., Kathleen C. Dudas, Julie A. Hanson, M. Bud Nelson, Philip T. LoVerde, and Michael A. Apicella. "The R-Type Pyocin of Pseudomonas aeruginosa C Is a Bacteriophage Tail-Like Particle That Contains Single-Stranded DNA." Infection and Immunity 67, no. 2 (1999): 717–25. http://dx.doi.org/10.1128/iai.67.2.717-725.1999.
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ABSTRACT Pseudomonas aeruginosa R-type pyocin particles have been described as bacteriocins that resemble bacteriophage tail-like structures. Because of their unusual structure, we reexamined whether they contained nucleic acids. Our data indicated that pyocin particles isolated from P. aeruginosa C (pyocin C) contain DNA. Probes generated from this DNA by the random-primer extension method hybridized to distinct bands in restriction endonuclease-digestedP. aeruginosa C genomic DNA. These probes also hybridized to genomic DNA from 6 of 18 P. aeruginosa strains that produced R-type pyocins. Asymmetric PCR, complementary oligonucleotide hybridization, and electron microscopy indicated that pyocin C particles contained closed circular single-stranded DNA, approximately 4.0 kb in length. Examination of total intracellular DNA from mitomycin C-induced cultures revealed the presence of two extrachromosomal DNA molecules, a double-stranded molecule and a single-stranded molecule, which hybridized to pyocin DNA. Sequence analysis of 7,480 nucleotides of P. aeruginosa C chromosomal DNA containing the pyocin DNA indicated the presence of pyocin open reading frames with similarities to open reading frames from filamentous phages and cryptic phage elements. We did not observe any similarities to known phage structural proteins or previously characterized pseudomonalprt genes expressing R-type pyocin structural proteins. These studies demonstrate that pyocin particles from P. aeruginosa C are defective phages that contain a novel closed circular single-stranded DNA and that this DNA was derived from the chromosome of P. aeruginosa C.
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Wen, Tong-Yue, Xing-Li Xie, Wei-Liang Kong, and Xiao-Qin Wu. "Expression and Antagonistic Activity Against Plant Pathogens of the Phage Tail-like Protein from Burkholderia multivorans WS-FJ9." Microorganisms 13, no. 4 (2025): 853. https://doi.org/10.3390/microorganisms13040853.
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Microorganisms exert antagonistic effects on pathogens through different mechanisms, thereby achieving biological control of plant diseases. Many Burkholderia strains can produce complex secondary metabolites and substances that have toxic effects on host cells. The phage tail-like bacteriocins (tailocins) is a compound with antibacterial activity. However, its function in B. multivorans has not yet been reported. This article explores the ability of B. multivorans WS-FJ9 to antagonise plant pathogenic fungi and oomycetes, screening the potential tailocins in the strain WS-FJ9 and verifying their function, to reveal its novel antimicrobial mechanisms. We found that WS-FJ9 had strong antagonistic effects on the plant pathogenic fungi Phomopsis macrospore and Sphaeropsis sapinea, and the pathogenic oomycete Phytophthora cinnamomi. The phage tail-like protein Bm_67459 was predicted from the WS-FJ9 strain genome. The Bm_67459 cDNA encoded 111 amino acid sequence, and the relative molecular weight was approximately 11.69 kDa, the theoretical isoelectric point (pI) was 5.49, and it was a hydrophilic protein. Bm_67459 had no transmembrane helix region or signal peptide, and it belonged to the Phage_TAC_7 super family. qRT-PCR results showed that Bm_67459 gene expression was significantly upregulated during contact between WS-FJ9 and P. cinnamomi. The purified Bm_67459 protein significantly inhibited P. cinnamomi mycelial growth at 10 μg·mL−1. In summary, the WS-FJ9 strain had broad-spectrum anti-phytopathogenic activity, and the tailocin Bm_67459 was an important effector against the plant pathogen P. cinnamomi, which helps to reveal the antagonistic mechanism of this strain at the molecular level and provides excellent strain resources for the biological control of plant diseases.
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Thappeta, Kishore Reddy Venkata, Kristin Ciezki, Nydia Morales-Soto, et al. "R-type bacteriocins of Xenorhabdus bovienii determine the outcome of interspecies competition in a natural host environment." Microbiology 166, no. 11 (2020): 1074–87. http://dx.doi.org/10.1099/mic.0.000981.
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Xenorhabdus species are bacterial symbionts of Steinernema nematodes and pathogens of susceptible insects. Different species of Steinernema nematodes carrying specific species of Xenorhabdus can invade the same insect, thereby setting up competition for nutrients within the insect environment. While Xenorhabdus species produce both diverse antibiotic compounds and prophage-derived R-type bacteriocins (xenorhabdicins), the functions of these molecules during competition in a host are not well understood. Xenorhabdus bovienii (Xb-Sj), the symbiont of Steinernema jollieti, possesses a remnant P2-like phage tail cluster, xbp1, that encodes genes for xenorhabdicin production. We show that inactivation of either tail sheath (xbpS1) or tail fibre (xbpH1) genes eliminated xenorhabdicin production. Preparations of Xb-Sj xenorhabdicin displayed a narrow spectrum of activity towards other Xenorhabdus and Photorhabdus species. One species, Xenorhabdus szentirmaii (Xsz-Sr), was highly sensitive to Xb-Sj xenorhabdicin but did not produce xenorhabdicin that was active against Xb-Sj. Instead, Xsz-Sr produced high-level antibiotic activity against Xb-Sj when grown in complex medium and lower levels when grown in defined medium (Grace’s medium). Conversely, Xb-Sj did not produce detectable levels of antibiotic activity against Xsz-Sr. To study the relative contributions of Xb-Sj xenorhabdicin and Xsz-Sr antibiotics in interspecies competition in which the respective Xenorhabdus species produce antagonistic activities against each other, we co-inoculated cultures with both Xenorhabdus species. In both types of media Xsz-Sr outcompeted Xb-Sj, suggesting that antibiotics produced by Xsz-Sr determined the outcome of the competition. In contrast, Xb-Sj outcompeted Xsz-Sr in competitions performed by co-injection in the insect Manduca sexta, while in competition with the xenorhabdicin-deficient strain (Xb-Sj:S1), Xsz-Sr was dominant. Thus, xenorhabdicin was required for Xb-Sj to outcompete Xsz-Sr in a natural host environment. These results highlight the importance of studying the role of antagonistic compounds under natural biological conditions.
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Dams, Dorien, Célia Pas, Agnieszka Latka, Zuzanna Drulis-Kawa, Lars Fieseler, and Yves Briers. "A VersaTile Approach to Reprogram the Specificity of the R2-Type Tailocin Towards Different Serotypes of Escherichia coli and Klebsiella pneumoniae." Antibiotics 14, no. 1 (2025): 104. https://doi.org/10.3390/antibiotics14010104.
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Background: Phage tail-like bacteriocins, or tailocins, provide a competitive advantage to producer cells by killing closely related bacteria. Morphologically similar to headless phages, their narrow target specificity is determined by receptor-binding proteins (RBPs). While RBP engineering has been used to alter the target range of a selected R2 tailocin from Pseudomonas aeruginosa, the process is labor-intensive, limiting broader application. Methods: We introduce a VersaTile-driven R2 tailocin engineering and screening platform to scale up RBP grafting. Results: This platform achieved three key milestones: (I) engineering R2 tailocins specific to Escherichia coli serogroups O26, O103, O104, O111, O145, O146, and O157; (II) reprogramming R2 tailocins to target, for the first time, the capsule and a new species, specifically the capsular serotype K1 of E. coli and K11 and K63 of Klebsiella pneumoniae; (III) creating the first bivalent tailocin with a branched RBP and cross-species activity, effective against both E. coli K1 and K. pneumoniae K11. Over 90% of engineered tailocins were effective, with clear pathways for further optimization identified. Conclusions: This work lays the groundwork for a scalable platform for the development of engineered tailocins, marking an important step towards making R2 tailocins a practical therapeutic tool for targeted bacterial infections.
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Rabsch, Wolfgang, Li Ma, Graham Wiley, et al. "FepA- and TonB-Dependent Bacteriophage H8: Receptor Binding and Genomic Sequence." Journal of Bacteriology 189, no. 15 (2007): 5658–74. http://dx.doi.org/10.1128/jb.00437-07.
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ABSTRACT H8 is derived from a collection of Salmonella enterica serotype Enteritidis bacteriophage. Its morphology and genomic structure closely resemble those of bacteriophage T5 in the family Siphoviridae. H8 infected S. enterica serotypes Enteritidis and Typhimurium and Escherichia coli by initial adsorption to the outer membrane protein FepA. Ferric enterobactin inhibited H8 binding to E. coli FepA (50% inhibition concentration, 98 nM), and other ferric catecholate receptors (Fiu, Cir, and IroN) did not participate in phage adsorption. H8 infection was TonB dependent, but exbB mutations in Salmonella or E. coli did not prevent infection; only exbB tolQ or exbB tolR double mutants were resistant to H8. Experiments with deletion and substitution mutants showed that the receptor-phage interaction first involves residues distributed over the protein's outer surface and then narrows to the same charged (R316) or aromatic (Y260) residues that participate in the binding and transport of ferric enterobactin and colicins B and D. These data rationalize the multifunctionality of FepA: toxic ligands like bacteriocins and phage penetrate the outer membrane by parasitizing residues in FepA that are adapted to the transport of the natural ligand, ferric enterobactin. DNA sequence determinations revealed the complete H8 genome of 104.4 kb. A total of 120 of its 143 predicted open reading frames (ORFS) were homologous to ORFS in T5, at a level of 84% identity and 89% similarity. As in T5, the H8 structural genes clustered on the chromosome according to their function in the phage life cycle. The T5 genome contains a large section of DNA that can be deleted and that is absent in H8: compared to T5, H8 contains a 9,000-bp deletion in the early region of its chromosome, and nine potentially unique gene products. Sequence analyses of the tail proteins of phages in the same family showed that relative to pb5 (Oad) of T5 and Hrs of BF23, the FepA-binding protein (Rbp) of H8 contains unique acidic and aromatic residues. These side chains may promote binding to basic and aromatic residues in FepA that normally function in the adsorption of ferric enterobactin. Furthermore, a predicted H8 tail protein showed extensive identity and similarity to pb2 of T5, suggesting that it also functions in pore formation through the cell envelope. The variable region of this protein contains a potential TonB box, intimating that it participates in the TonB-dependent stage of the phage infection process.
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Liu, Jian, Peng Chen, Congyi Zheng, and Yu-Ping Huang. "Characterization of Maltocin P28, a Novel Phage Tail-Like Bacteriocin from Stenotrophomonas maltophilia." Applied and Environmental Microbiology 79, no. 18 (2013): 5593–600. http://dx.doi.org/10.1128/aem.01648-13.
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ABSTRACTStenotrophomonas maltophiliais an important global opportunistic pathogen for which limited therapeutics are available because of the emergence of multidrug-resistant strains. A novel bacteriocin, maltocin P28, which is produced byS. maltophiliastrain P28, may be the first identified phage tail-like bacteriocin fromS. maltophilia. Maltocin P28 resembles a contractile but nonflexible phage tail structure based on electron microscopy, and it is sensitive to trypsin, proteinase K, and heat. SDS-PAGE analysis of maltocin P28 revealed two major protein bands of approximately 43 and 20 kDa. The N-terminal amino acid residues of these two major subunits were sequenced, and the maltocin P28 gene cluster was located on theS. maltophiliaP28 chromosome. Our sequence analysis results indicate that this maltocin gene cluster consists of 23 open reading frames (ORFs), and that its gene organization is similar to that of the P2 phage genome and R2 pyocin gene cluster. ORF17 and ORF18 encode the two major structural proteins, which correspond to gpFI (tail sheath) and gpFII (tail tube) of P2 phage, respectively. We found that maltocin P28 had bactericidal activity against 38 of 81 testedS. maltophiliastrains. Therefore, maltocin P28 is a promising therapeutic substitute for antibiotics forS. maltophiliainfections.
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Strauch, Eckhard, Heike Kaspar, Christoph Schaudinn, et al. "Characterization of Enterocoliticin, a Phage Tail-Like Bacteriocin, and Its Effect on Pathogenic Yersinia enterocolitica Strains." Applied and Environmental Microbiology 67, no. 12 (2001): 5634–42. http://dx.doi.org/10.1128/aem.67.12.5634-5642.2001.
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ABSTRACT Yersinia enterocolitica 29930 (biogroup 1A; serogroup O:7,8) produces a bacteriocin, designated enterocoliticin, that shows inhibitory activity against enteropathogenic strains of Y. enterocolitica belonging to serogroups O:3, O:5,27 and O:9. Enterocoliticin was purified, and electron micrographs of enterocoliticin preparations revealed the presence of phage tail-like particles. The particles did not contain nucleic acids and showed contraction upon contact with susceptible bacteria. Enterocoliticin addition to logarithmic-phase cultures of susceptible bacterial strains led to a rapid dose-dependent reduction in CFU. Calorimetric measurements of the heat output of cultures of sensitive bacteria showed a complete loss of cellular metabolic activity immediately upon addition of enterocoliticin. Furthermore, a dose-dependent efflux of K+ ions into the medium was determined, indicating that enterocoliticin has channel-forming activity.
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Chen, J., Y. Zhu, M. Yin, Y. Xu, X. Liang, and Y. ‐P Huang. "Characterization of maltocin S16, a phage tail‐like bacteriocin with antibacterial activity againstStenotrophomonas maltophiliaandEscherichia coli." Journal of Applied Microbiology 127, no. 1 (2019): 78–87. http://dx.doi.org/10.1111/jam.14294.
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McGillivary, Glen, Andrew P. Tomaras, Eric R. Rhodes, and Luis A. Actis. "Cloning and Sequencing of a Genomic Island Found in the Brazilian Purpuric Fever Clone of Haemophilus influenzae Biogroup Aegyptius." Infection and Immunity 73, no. 4 (2005): 1927–38. http://dx.doi.org/10.1128/iai.73.4.1927-1938.2005.
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ABSTRACT A genomic island was identified in the Haemophilus influenzae biogroup aegyptius Brazilian purpuric fever (BPF) strain F3031. This island, which was also found in other BPF isolates, could not be detected in non-BPF biogroup aegyptius strains or in nontypeable or typeable H. influenzae strains, with the exception of a region present in the type b Eagan strain. This 34,378-bp island is inserted, in reference to H. influenzae Rd KW20, within a choline transport gene and contains a mosaic structure of Mu-like prophage genes, several hypothetical genes, and genes potentially encoding an Erwinia carotovora carotovoricin Er-like bacteriocin. The product of the tail fiber ORF in the bacteriocin-like region shows a hybrid structure where the C terminus is similar to an H. influenzae phage HP1 tail protein implicating this open reading frame in altering host specificity for a putative bacteriocin. Significant synteny is seen in the entire genomic island with genomic regions from Salmonella enterica subsp. enterica serovar Typhi CT18, Photorhabdus luminescens subsp. laumondii TT01, Chromobacterium violaceum, and to a lesser extent Haemophilus ducreyi 35000HP. In a previous work, we isolated several BPF-specific DNA fragments through a genome subtraction procedure, and we have found that a majority of these fragments map to this locus. In addition, several subtracted fragments generated from an independent laboratory by using different but related strains also map to this island. These findings underscore the importance of this BPF-specific chromosomal region in explaining some of the genomic differences between highly invasive BPF strains and non-BPF isolates of biogroup aegyptius.
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Nguyen, Hoa Anh, Toshio Tomita, Morihiko Hirota, Jun Kaneko, Tetsuya Hayashi, and Yoshiyuki Kamio. "DNA Inversion in the Tail Fiber Gene Alters the Host Range Specificity of Carotovoricin Er, a Phage-Tail-Like Bacteriocin of Phytopathogenic Erwinia carotovora subsp.carotovora Er." Journal of Bacteriology 183, no. 21 (2001): 6274–81. http://dx.doi.org/10.1128/jb.183.21.6274-6281.2001.
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ABSTRACT Carotovoricin Er is a phage-tail-like bacteriocin produced byErwinia carotovora subsp. carotovorastrain Er, a causative agent for soft rot disease in plants. Here we studied binding and killing spectra of carotovoricin Er preparations for various strains of the bacterium (strains 645Ar, EC-2, N786, and P7) and found that the preparations contain two types of carotovoricin Er with different host specificities; carotovoricin Era possessing a tail fiber protein of 68 kDa killed strains 645Ar and EC-2, while carotovoricin Erb with a tail fiber protein of 76 kDa killed strains N786 and P7. The tail fiber proteins of 68 and 76 kDa had identical N-terminal amino acid sequences for at least 11 residues. A search of the carotovoricin Er region in the chromosome of strain Er indicated the occurrence of a DNA inversion system for the tail fiber protein consisting of (i) two 26-bp inverted repeats inside and downstream of the tail fiber gene that flank a 790-bp fragment and (ii) a putative DNA invertase gene with a 90-bp recombinational enhancer sequence. In fact, when a 1,400-bp region containing the 790-bp fragment was amplified by a PCR using the chromosomal DNA of strain Er as the template, both the forward and the reverse nucleotide sequences of the 790-bp fragment were detected. DNA inversion of the 790-bp fragment also occurred in Escherichia coli DH5α when two compatible plasmids carrying either the 790-bp fragment or the invertase gene were cotransformed into the bacterium. Furthermore, hybrid carotovoricin CGE possessing the tail fiber protein of 68 or 76 kDa exhibited a host range specificity corresponding to that of carotovoricin Era or Erb, respectively. Thus, a DNA inversion altered the C-terminal part of the tail fiber protein of carotovoricin Er, altering the host range specificity of the bacteriocin.
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Jabrane, Abdelhamid, Ahmed Sabri, Philippe Compère, et al. "Characterization of Serracin P, a Phage-Tail-Like Bacteriocin, and Its Activity against Erwinia amylovora, the Fire Blight Pathogen." Applied and Environmental Microbiology 68, no. 11 (2002): 5704–10. http://dx.doi.org/10.1128/aem.68.11.5704-5710.2002.
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ABSTRACT Serratia plymithicum J7 culture supernatant displayed activity against many pathogenic strains of Erwinia amylovora, the causal agent of the most serious bacterial disease of apple and pear trees, fire blight, and against Klebsiella pneumoniae, Serratia liquefaciens, Serratia marcescens, and Pseudomonas fluorescens. This activity increased significantly upon induction with mitomycin C. A phage-tail-like bacteriocin, named serracin P, was purified from an induced culture supernatant of S. plymithicum J7. It was found to be the only compound involved in the antibacterial activity against sensitive strains. The N-terminal amino acid sequence analysis of the two major subunits (23 and 43 kDa) of serracin P revealed high homology with the Fels-2 prophage of Salmonella enterica, the coliphages P2 and 168, the φCTX prophage of Pseudomonas aeruginosa, and a prophage of Yersinia pestis. This strongly suggests a common ancestry for serracin P and these bacteriophages.
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Thaler, J. O., S. Baghdiguian, and N. Boemare. "Purification and characterization of xenorhabdicin, a phage tail-like bacteriocin, from the lysogenic strain F1 of Xenorhabdus nematophilus." Applied and environmental microbiology 61, no. 5 (1995): 2049–52. http://dx.doi.org/10.1128/aem.61.5.2049-2052.1995.
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NGUYEN, Anh Hoa, Toshio TOMITA, Morihiko HIROTA, Tsuruji SATO, and Yoshiyuki KAMIO. "A Simple Purification Method and Morphology and Component Analyses for Carotovoricin Er, a Phage-tail-like Bacteriocin from the Plant PathogenErwinia carotovoraEr." Bioscience, Biotechnology, and Biochemistry 63, no. 8 (1999): 1360–69. http://dx.doi.org/10.1271/bbb.63.1360.
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OGATA, S., and M. HONGO. "Lysis Induced by Sodium Ion and Its Relation to Lytic Enzyme Systems in Clostridium saccharoperbutylacetonicum." Microbiology 81, no. 2 (2000): 315–23. http://dx.doi.org/10.1099/00221287-81-2-315.
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Summary: Growing Clostridium saccharoperbutylacetonicum was lysed by sodium ion concentrations above o'I M (maximum effect at 0.3 M). The rate of lysis depended on the age of the culture. The most rapid lysis occurred in organisms from logarithmically growing cultures which were incubated for 3 to 5 h; organisms from stationary phase cultures were completely resistant to Na+-induced lysis. Sodium ion-induced lysis was related to autolysis of the organisms and was greatly affected by pH and temperature. The optimum pH was about 6.0, and the optimum temperature 35°C. Various chemical inhibitors, including known enzyme inhibitors (such as Cu2+ and p-chloromercuribenzoate) and fixative agents (such as formalin and glutaraldehyde), inhibited the lysis, while organisms whose growth had been inhibited by antibiotics such as tetracycline, were also resistant to Na+-induced lysis. The lysate produced by Na+-treatment itself had lytic activity on isolated walls, thought to be due to its content of autolysin. About 3o to 6o min after mitomycin C treatment (which induced the production of the phage tail-like bacteriocin clostocin O), the organisms were temporarily resistant to Na+-induced lysis. However the organisms reverted to the state of high sensitivity to Na+ when clostocin O-associated endolysin was produced. We suggest that Na+-induced lysis is due to the action of wall lytic enzymes such as autolysin and clostocin O-endolysin.
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Damasko, C., A. Konietzny, H. Kaspar, B. Appel, P. Dersch, and E. Strauch. "Studies of the Efficacy of Enterocoliticin, a Phage-Tail Like Bacteriocin, as Antimicrobial Agent Against Yersinia enterocolitica Serotype O3 in a Cell Culture System and in Mice." Journal of Veterinary Medicine Series B 52, no. 4 (2005): 171–79. http://dx.doi.org/10.1111/j.1439-0450.2005.00841.x.
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Yamada, Kazuteru, Jun Kaneko, Yoshiyuki Kamio, and Yoshifumi Itoh. "Binding Sequences for RdgB, a DNA Damage-Responsive Transcriptional Activator, and Temperature-Dependent Expression of Bacteriocin and Pectin Lyase Genes in Pectobacterium carotovorum subsp. carotovorum." Applied and Environmental Microbiology 74, no. 19 (2008): 6017–25. http://dx.doi.org/10.1128/aem.01297-08.
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ABSTRACT Pectobacterium carotovorum subsp. carotovorum strain Er simultaneously produces the phage tail-like bacteriocin carotovoricin (Ctv) and pectin lyase (Pnl) in response to DNA-damaging agents. The regulatory protein RdgB of the Mor/C family of proteins activates transcription of pnl through binding to the promoter. However, the optimal temperature for the synthesis of Ctv (23�C) differs from that for synthesis of Pnl (30�C), raising the question of whether RdgB directly activates ctv transcription. Here we report that RdgB directly regulates Ctv synthesis. Gel mobility shift assays demonstrated RdgB binding to the P0, P1, and P2 promoters of the ctv operons, and DNase I footprinting determined RdgB-binding sequences (RdgB boxes) on these and on the pnl promoters. The RdgB box of the pnl promoter included a perfect 7-bp inverted repeat with high binding affinity to the regulator (K d [dissociation constant] = 150 nM). In contrast, RdgB boxes of the ctv promoters contained an imperfect inverted repeat with two or three mismatches that consequently reduced binding affinity (K d = 250 to 350 nM). Transcription of the rdgB and ctv genes was about doubled at 23�C compared with that at 30�C. In contrast, the amount of pnl transcription tripled at 30�C. Thus, the inverse synthesis of Ctv and Pnl as a function of temperature is apparently controlled at the transcriptional level, and reduced rdgB expression at 30�C obviously affected transcription from the ctv promoters with low-affinity RdgB boxes. Pathogenicity toward potato tubers was reduced in an rdgB knockout mutant, suggesting that the RdgAB system contributes to the pathogenicity of this bacterium, probably by activating pnl expression.
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Strauch, Eckhard, Greta Goelz, Dorothea Knabner, Antje Konietzny, Erich Lanka, and Bernd Appel. "A cryptic plasmid of Yersinia enterocolitica encodes a conjugative transfer system related to the regions of CloDF13 Mob and IncX Pil." Microbiology 149, no. 10 (2003): 2829–45. http://dx.doi.org/10.1099/mic.0.26418-0.
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Yersinia enterocolitica 29930 (biotype 1A; O : 7,8), the producing strain of the phage-tail-like bacteriocin enterocoliticin, possesses a plasmid-encoded conjugative type IV transfer system. The genes of the conjugative system were found by screening of a cosmid library constructed from total DNA of strain 29930. The cosmid Cos100 consists of the vector SuperCos1 and an insert DNA of 40 303 bp derived from a cryptic plasmid of strain 29930. The conjugative transfer system consists of genes encoding a DNA transfer and replication system (Dtr) with close relationship to the mob region of the mobilizable plasmid CloDF13 and a gene cluster encoding a mating pair formation system (Mpf) closely related to the Mpf system of the IncX plasmid R6K. However, a gene encoding a homologue of TaxB, the coupling protein of the IncX system, is missing. The whole transfer region has a size of approximately 17 kb. The recombinant plasmid Cos100 was shown to be transferable between Escherichia coli and Yersinia with transfer frequencies up to 0·1 transconjugants per donor. Mutations generated by inserting a tetracycline cassette into putative tri genes yielded a transfer-deficient phenotype. Conjugative transfer of the cryptic plasmid could not be demonstrated in the original host Y. enterocolitica 29930. However, a kanamycin-resistance-conferring derivative of the plasmid was successfully introduced into E. coli K-12 by transformation and was shown to be self-transmissible. Furthermore, Southern blot hybridization and PCR experiments were carried out to elucidate the distribution of the conjugative transfer system in Yersinia. In total, six Y. enterocolitica biotype 1A strains harbouring closely related systems on endogenous plasmids were identified.
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Takala, Timo M., Samira Mokhtari, Susanna L. Ahonen, Xing Wan, and Per E. J. Saris. "Wild-type Lactococcus lactis producing bacteriocin-like prophage lysins." Frontiers in Microbiology 14 (July 14, 2023). http://dx.doi.org/10.3389/fmicb.2023.1219723.
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IntroductionLactococcus is a genus of lactic acid bacteria used in the dairy industry as a starter. Lactococci have been found to produce altogether more than 40 different bacteriocins, ribosomally synthesized antimicrobial proteins. All known Lactococcus spp. bacteriocins belong to classes I and II, which are mainly heat-resistant peptides. No class III bacteriocins, bigger heat-sensitive proteins, including phage tail-like bacteriocins, have been found from the Lactococcus spp. Unlike phage tail-like bacteriocins, prophage lysins have not been regarded as bacteriocins, possibly because phage lysins contribute to autolysis, degrading the host's own cell wall.MethodsWild-type Lactococcus lactis strain LAC460, isolated from spontaneously fermented idli batter, was examined for its antimicrobial activity. We sequenced the genome, searched phage lysins from the culture supernatant, and created knock-out mutants to find out the source of the antimicrobial activity.Results and discussionThe strain LAC460 was shown to kill other Lactococcus strains with protease- and heat-sensitive lytic activity. Three phage lysins were identified in the culture supernatant. The genes encoding the three lysins were localized in different prophage regions in the chromosome. By knock-out mutants, two of the lysins, namely LysL and LysP, were demonstrated to be responsible for the antimicrobial activity. The strain LAC460 was found to be resistant to the lytic action of its own culture supernatant, and as a consequence, the phage lysins could behave like bacteriocins targeting and killing other closely related bacteria. Hence, similar to phage tail-like bacteriocins, phage lysin-like bacteriocins could be regarded as a novel type of class III bacteriocins.
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Argov, Tal, Shai Ran Sapir, Anna Pasechnek, et al. "Coordination of cohabiting phage elements supports bacteria–phage cooperation." Nature Communications 10, no. 1 (2019). http://dx.doi.org/10.1038/s41467-019-13296-x.
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AbstractBacterial pathogens often carry multiple prophages and other phage-derived elements within their genome, some of which can produce viral particles in response to stress. Listeria monocytogenes 10403S harbors two phage elements in its chromosome, both of which can trigger bacterial lysis under stress: an active prophage (ϕ10403S) that promotes the virulence of its host and can produce infective virions, and a locus encoding phage tail-like bacteriocins. Here, we show that the two phage elements are co-regulated, with the bacteriocin locus controlling the induction of the prophage and thus its activity as a virulence-associated molecular switch. More specifically, a metalloprotease encoded in the bacteriocin locus is upregulated in response to stress and acts as an anti-repressor for CI-like repressors encoded in each phage element. Our results provide molecular insight into the phenomenon of polylysogeny and its intricate adaptation to complex environments.
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Látrová, Klára, Tereza Dolejšová, Lucia Motlová, et al. "R-Type Fonticins Produced by Pragia fontium Form Large Pores with High Conductance." Journal of Bacteriology, December 21, 2022. http://dx.doi.org/10.1128/jb.00315-22.
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Phage tail-like bacteriocins are now the subject of research as potent antibacterial agents due to their narrow host specificity and single-hit mode of action. In this work, we focused on the structure and mode of action of fonticins.
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Ibarguren-Quiles, Clara, Inés Bleriot, Lucía Blasco, et al. "The world of phage tail-like bacteriocins: State of the art and biotechnological perspectives." February 7, 2025. https://doi.org/10.1016/j.micres.2025.128121.
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In the struggle for resources, bacteria have developed different systems of competition, including the type VI secretion system (T6SS) and phage tail-like bacteriocins (PTLBs), that act by killing other bacterial species or strains from the same species. The emergence of antimicrobial resistance (AMR) is an urgent global health problem. In this context, the need to develop new antimicrobial agents has put PTLBs in the spotlight. This review focuses on the most relevant aspects of PTLBs such as their structural features, biology, the technological tools to improve their application, and the most importantly their patents.
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Kandel, Prem P., David A. Baltrus, and Kevin L. Hockett. "Pseudomonas Can Survive Tailocin Killing via Persistence-Like and Heterogenous Resistance Mechanisms." Journal of Bacteriology 202, no. 13 (2020). http://dx.doi.org/10.1128/jb.00142-20.
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ABSTRACT Phage tail-like bacteriocins (tailocins) are bacterially produced protein toxins that mediate competitive interactions between cocolonizing bacteria. Both theoretical and experimental research has shown there are intransitive interactions between bacteriocin-producing, bacteriocin-sensitive, and bacteriocin-resistant populations, whereby producers outcompete sensitive cells, sensitive cells outcompete resistant cells, and resistant cells outcompete producers. These so-called rock-paper-scissors dynamics explain how all three populations occupy the same environment, without one driving the others extinct. Using Pseudomonas syringae as a model, we demonstrate that otherwise sensitive cells survive bacteriocin exposure through a physiological mechanism. This mechanism allows cells to survive bacteriocin killing without acquiring resistance. We show that a significant fraction of the target cells that survive a lethal dose of tailocin did not exhibit any detectable increase in survival during a subsequent exposure. Tailocin persister cells were more prevalent in stationary- rather than log-phase cultures. Of the fraction of cells that gained detectable resistance, there was a range from complete (insensitive) to incomplete (partially sensitive) resistance. By using genomic sequencing and genetic engineering, we showed that a mutation in a hypothetical gene containing 8 to 10 transmembrane domains causes tailocin high persistence and that genes of various glycosyltransferases cause incomplete and complete tailocin resistance. Importantly, of the several classes of mutations, only those causing complete tailocin resistance compromised host fitness. This result indicates that bacteria likely utilize persistence to survive bacteriocin-mediated killing without suffering the costs associated with resistance. This research provides important insight into how bacteria can escape the trap of fitness trade-offs associated with gaining de novo tailocin resistance. IMPORTANCE Bacteriocins are bacterially produced protein toxins that are proposed as antibiotic alternatives. However, a deeper understanding of the responses of target bacteria to bacteriocin exposure is lacking. Here, we show that target cells of Pseudomonas syringae survive lethal bacteriocin exposure through both physiological persistence and genetic resistance mechanisms. Cells that are not growing rapidly rely primarily on persistence, whereas those growing rapidly are more likely to survive via resistance. We identified various mutations in lipopolysaccharide biogenesis-related regions involved in tailocin persistence and resistance. By assessing host fitness of various classes of mutants, we showed that persistence and subtle resistance are mechanisms P. syringae uses to survive competition and preserve host fitness. These results have important implications for developing bacteriocins as alternative therapeutic agents.
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Blasco, Lucía, de Aledo Manuel Gónzalez, Concha Ortiz-Cartagena, et al. "Study of 32 new phage tail‑like bacteriocins (pyocins) from a clinical collection of Pseudomonas aeruginosa and of their potential use as typing markers and antimicrobial agents." January 3, 2023. https://doi.org/10.1038/s41598-022-27341-1.
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Phage tail-like bacteriocins (PTLBs) are large proteomic structures similar to the tail phages. These structures function in bacterial competition by making pores in the membrane of their competitors. The PTLBs identified in Pseudomonas aeruginosa are known as R-type and F-type pyocins, which have a narrow spectrum of action. Their specificity is determined by the tail fiber and is closely related to the lipopolysaccharide type of the target competitor strain. In this study, the genome sequences of 32 clinical of P. aeruginosa clinical isolates were analysed to investigate the presence of R-type and F-type pyocins, and one was detected in all strains tested. The pyocins were classified into 4 groups on the basis of the tail fiber and also the homology, phylogeny and structure of the cluster components. A relationship was established between these groups and the sequence type and serotype of the strain of origin and finally the killing spectrum of the representative pyocins was determined showing a variable range of activity between 0 and 37.5%. The findings showed that these pyocins could potentially be used for typing of P. aeruginosa clinical isolates, on the basis of their genomic sequence and cluster structure, and also as antimicrobial agents.
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Umansky, Andrew A., and Louis Charles Fortier. "The long and sinuous road to phage-based therapy of Clostridioides difficile infections." Frontiers in Medicine 10 (August 23, 2023). http://dx.doi.org/10.3389/fmed.2023.1259427.
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With the antibiotic crisis and the rise in antimicrobial resistance worldwide, new therapeutic alternatives are urgently needed. Phage therapy represents one of the most promising alternatives but for some pathogens, such as Clostridioides difficile, important challenges are being faced. The perspective of phage therapy to treat C. difficile infections is complicated by the fact that no strictly lytic phages have been identified so far, and current temperate phages generally have a narrow host range. C. difficile also harbors multiple antiphage mechanisms, and the bacterial genome is often a host of one or multiple prophages that can interfere with lytic phage infection. Nevertheless, due to recent advances in phage host receptor recognition and improvements in genetic tools to manipulate phage genomes, it is now conceivable to genetically engineer C. difficile phages to make them suitable for phage therapy. Other phage-based alternatives such as phage endolysins and phage tail-like bacteriocins (avidocins) are also being investigated but these approaches also have their own limitations and challenges. Last but not least, C. difficile produces spores that are resistant to phage attacks and all current antibiotics, and this complicates therapeutic interventions. This mini-review gives a brief historical overview of phage work that has been carried out in C. difficile, presents recent advances in the field, and addresses the most important challenges that are being faced, with potential solutions.
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Blasco, Lucía, Manuel González de Aledo, Concha Ortiz-Cartagena, et al. "Study of 32 new phage tail-like bacteriocins (pyocins) from a clinical collection of Pseudomonas aeruginosa and of their potential use as typing markers and antimicrobial agents." Scientific Reports 13, no. 1 (2023). http://dx.doi.org/10.1038/s41598-022-27341-1.
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AbstractPhage tail-like bacteriocins (PTLBs) are large proteomic structures similar to the tail phages. These structures function in bacterial competition by making pores in the membrane of their competitors. The PTLBs identified in Pseudomonas aeruginosa are known as R-type and F-type pyocins, which have a narrow spectrum of action. Their specificity is determined by the tail fiber and is closely related to the lipopolysaccharide type of the target competitor strain. In this study, the genome sequences of 32 clinical of P. aeruginosa clinical isolates were analysed to investigate the presence of R-type and F-type pyocins, and one was detected in all strains tested. The pyocins were classified into 4 groups on the basis of the tail fiber and also the homology, phylogeny and structure of the cluster components. A relationship was established between these groups and the sequence type and serotype of the strain of origin and finally the killing spectrum of the representative pyocins was determined showing a variable range of activity between 0 and 37.5%. The findings showed that these pyocins could potentially be used for typing of P. aeruginosa clinical isolates, on the basis of their genomic sequence and cluster structure, and also as antimicrobial agents.
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Mei, Madeline, Jacob Thomas, and Stephen Diggle. "Heterogenous susceptibility to R-pyocins in populations of Pseudomonas aeruginosa sourced from cystic fibrosis lungs." Access Microbiology 4, no. 5 (2022). http://dx.doi.org/10.1099/acmi.ac2021.po0209.
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Bacteriocins are proteinaceous antimicrobials produced by bacteria which are active against other strains of the same species. R-type pyocins are phage tail-like bacteriocins produced by Pseudomonas aeruginosa. Due to their anti-pseudomonal activity, R-pyocins have potential as therapeutics in infection. P. aeruginosa is a Gram-negative opportunistic pathogen and is particularly problematic for individuals with cystic fibrosis (CF). P. aeruginosa from CF lung infections develop increasing resistance to antibiotics, making new treatment approaches essential. P. aeruginosa populations become phenotypically and genotypically diverse during infection, however, little is known of the efficacy of R-pyocins against heterogeneous populations. R-pyocins vary by subtype (R1-R5), distinguished by binding to different residues on the lipopolysaccharide (LPS). Each type varies in killing spectrum, and each strain produces only one R-type. To evaluate the prevalence of different R-types, we screened P. aeruginosastrains from the International Pseudomonas Consortium Database (IPCD) and from our biobank of CF strains. We found that (i) R1-types were the most prevalent R-type among strains from respiratory sources; (ii) there are a large number of strains lacking R-pyocin genes, and (iii) isolates collected from the same patient have the same R-type. We then assessed the impact of diversity on R-pyocin susceptibility and found a heterogenous response to R-pyocins within populations, likely due to differences in the LPS core. Our work reveals that heterogeneous populations of microbes exhibit variable susceptibility to R-pyocins and highlights that there is likely heterogeneity in response to other types of LPS-binding antimicrobials, including phage.
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Mei, Madeline, Preston Pheng, Detriana Kurzeja-Edwards, and Stephen P. Diggle. "High prevalence of lipopolysaccharide mutants and R2-pyocin susceptible variants in Pseudomonas aeruginosa populations sourced from cystic fibrosis lung infections." Microbiology Spectrum, October 25, 2023. http://dx.doi.org/10.1128/spectrum.01773-23.
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ABSTRACT Chronic, highly antibiotic-resistant infections in cystic fibrosis (CF) lungs contribute to increasing morbidity and mortality. Pseudomonas aeruginosa , a common CF pathogen, exhibits resistance to multiple antibiotics, contributing to antimicrobial resistance (AMR). These bacterial populations display genetic and phenotypic diversity, but it is unclear how this diversity affects susceptibility to bacteriocins. R-pyocins, i.e., bacteriocins produced by P. aeruginosa , are phage-tail-like antimicrobials. R-pyocins have potential as antimicrobials, however, recent research suggests the diversity of P. aeruginosa variants within CF lung infections leads to varying susceptibility to R-pyocins. This variation may be linked to changes in lipopolysaccharide (LPS), acting as the R-pyocin receptor. Currently, it is unknown how frequently R-pyocin-susceptible strains are in chronic CF lung infection, particularly when considering the heterogeneity within these strains. In this study, we tested the R2-pyocin susceptibility of 139 P . aeruginosa variants from 17 sputum samples of 7 CF patients and analyzed LPS phenotypes. We found that 83% of sputum samples did not have R2-pyocin-resistant variants, while nearly all samples contained susceptible variants. There was no correlation between LPS phenotype and R2-pyocin susceptibility, though we estimate that about 76% of sputum-derived variants lack an O-specific antigen, 40% lack a common antigen, and 24% have altered LPS cores. The absence of a correlation between LPS phenotype and R-pyocin susceptibility suggests that LPS packing density may play a significant role in R-pyocin susceptibility among CF variants. Our research supports the potential of R-pyocins as therapeutic agents, as many infectious CF variants are susceptible to R2-pyocins, even within diverse bacterial populations. IMPORTANCE Cystic fibrosis (CF) patients often experience chronic, debilitating lung infections caused by antibiotic-resistant Pseudomonas aeruginosa , contributing to antimicrobial resistance (AMR). The genetic and phenotypic diversity of P. aeruginosa populations in CF lungs raises questions about their susceptibility to non-traditional antimicrobials, like bacteriocins. In this study, we focused on R-pyocins, a type of bacteriocin with high potency and a narrow killing spectrum. Our findings indicate that a large number of infectious CF variants are susceptible to R2-pyocins, even within diverse bacterial populations, supporting their potential use as therapeutic agents. The absence of a clear correlation between lipopolysaccharide (LPS) phenotypes and R-pyocin susceptibility suggests that LPS packing density may play a significant role in R-pyocin susceptibility among CF variants. Understanding the relationship between LPS phenotypes and R-pyocin susceptibility is crucial for developing effective treatments for these chronic infections.
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Boeckaerts, Dimitri, Michiel Stock, Bjorn Criel, Hans Gerstmans, Bernard De Baets, and Yves Briers. "Predicting bacteriophage hosts based on sequences of annotated receptor-binding proteins." Scientific Reports 11, no. 1 (2021). http://dx.doi.org/10.1038/s41598-021-81063-4.
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AbstractNowadays, bacteriophages are increasingly considered as an alternative treatment for a variety of bacterial infections in cases where classical antibiotics have become ineffective. However, characterizing the host specificity of phages remains a labor- and time-intensive process. In order to alleviate this burden, we have developed a new machine-learning-based pipeline to predict bacteriophage hosts based on annotated receptor-binding protein (RBP) sequence data. We focus on predicting bacterial hosts from the ESKAPE group, Escherichia coli, Salmonella enterica and Clostridium difficile. We compare the performance of our predictive model with that of the widely used Basic Local Alignment Search Tool (BLAST). Our best-performing predictive model reaches Precision-Recall Area Under the Curve (PR-AUC) scores between 73.6 and 93.8% for different levels of sequence similarity in the collected data. Our model reaches a performance comparable to that of BLASTp when sequence similarity in the data is high and starts outperforming BLASTp when sequence similarity drops below 75%. Therefore, our machine learning methods can be especially useful in settings in which sequence similarity to other known sequences is low. Predicting the hosts of novel metagenomic RBP sequences could extend our toolbox to tune the host spectrum of phages or phage tail-like bacteriocins by swapping RBPs.
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Backman, Talia, Sergio M. Latorre, Efthymia Symeonidi, et al. "A phage tail–like bacteriocin suppresses competitors in metapopulations of pathogenic bacteria." Science 384, no. 6701 (2024). http://dx.doi.org/10.1126/science.ado0713.
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Bacteria can repurpose their own bacteriophage viruses (phage) to kill competing bacteria. Phage-derived elements are frequently strain specific in their killing activity, although there is limited evidence that this specificity drives bacterial population dynamics. Here, we identified intact phage and their derived elements in a metapopulation of wild plant–associated Pseudomonas genomes. We discovered that the most abundant viral cluster encodes a phage remnant resembling a phage tail called a tailocin, which bacteria have co-opted to kill bacterial competitors. Each pathogenic Pseudomonas strain carries one of a few distinct tailocin variants that target the variable polysaccharides in the outer membrane of co-occurring pathogenic Pseudomonas strains. Analysis of herbarium samples from the past 170 years revealed that the same tailocin and bacterial receptor variants have persisted in Pseudomonas populations. These results suggest that tailocin genetic diversity can be mined to develop targeted “tailocin cocktails” for microbial control.
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Gu, Zhiwei, Xiaofei Ge, and Jiawei Wang. "Structure of an F-type phage tail-like bacteriocin from Listeria monocytogenes." Nature Communications 16, no. 1 (2025). https://doi.org/10.1038/s41467-025-57075-3.
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"Erratum for the Research Article “A phage tail–like bacteriocin suppresses competitors in metapopulations of pathogenic bacteria” by T. Backman et al ." Science 388, no. 6743 (2025). https://doi.org/10.1126/science.adx9434.
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Yao, Guichun W., Iris Duarte, Tram T. Le, et al. "A Broad-Host-Range Tailocin from Burkholderia cenocepacia." Applied and Environmental Microbiology 83, no. 10 (2017). http://dx.doi.org/10.1128/aem.03414-16.
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ABSTRACT The Burkholderia cepacia complex (Bcc) consists of 20 closely related Gram-negative bacterial species that are significant pathogens for persons with cystic fibrosis (CF). Some Bcc strains are highly transmissible and resistant to multiple antibiotics, making infection difficult to treat. A tailocin (phage tail-like bacteriocin), designated BceTMilo, with a broad host range against members of the Bcc, was identified in B. cenocepacia strain BC0425. Sixty-eight percent of Bcc representing 10 species and 90% of non-Bcc Burkholderia strains tested were sensitive to BceTMilo. BceTMilo also showed killing activity against Pseudomonas aeruginosa PAO1 and derivatives. Liquid chromatography-mass spectrometry analysis of the major BceTMilo proteins was used to identify a 23-kb tailocin locus in a draft BC0425 genome. The BceTMilo locus was syntenic and highly similar to a 24.6-kb region on chromosome 1 of B. cenocepacia J2315 (BCAL0081 to BCAL0107). A close relationship and synteny were observed between BceTMilo and Burkholderia phage KL3 and, by extension, with paradigm temperate myophage P2. Deletion mutants in the gene cluster encoding enzymes for biosynthesis of lipopolysaccharide (LPS) in the indicator strain B. cenocepacia K56-2 conferred resistance to BceTMilo. Analysis of the defined mutants in LPS biosynthetic genes indicated that an α-d-glucose residue in the core oligosaccharide is the receptor for BceTMilo. IMPORTANCE BceTMilo, presented in this study, is a broad-host-range tailocin active against Burkholderia spp. As such, BceTMilo and related or modified tailocins have potential as bactericidal therapeutic agents against plant- and human-pathogenic Burkholderia.
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Babar, Tauseef K., Travis R. Glare, John G. Hampton, et al. "Linocin M18 protein from the insect pathogenic bacterium Brevibacillus laterosporus isolates." Applied Microbiology and Biotechnology, May 19, 2023. http://dx.doi.org/10.1007/s00253-023-12563-8.
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Abstract Brevibacillus laterosporus (Bl) is a Gram-positive and spore-forming bacterium. Insect pathogenic strains have been characterised in New Zealand, and two isolates, Bl 1821L and Bl 1951, are under development for use in biopesticides. However, growth in culture is sometimes disrupted, affecting mass production. Based on previous work, it was hypothesised that Tectiviridae phages might be implicated. While investigating the cause of the disrupted growth, electron micrographs of crude lysates showed structural components of putative phages including capsid and tail-like structures. Sucrose density gradient purification yielded a putative self-killing protein of ~30 kDa. N-terminal sequencing of the ~30 kDa protein identified matches to a predicted 25 kDa hypothetical and a 31.4 kDa putative encapsulating protein homologs, with the genes encoding each protein adjacent in the genomes. BLASTp analysis of the homologs of 31.4 kDa amino acid sequences shared 98.6% amino acid identity to the Linocin M18 bacteriocin family protein of Brevibacterium sp. JNUCC-42. Bioinformatic tools including AMPA and CellPPD defined that the bactericidal potential originated from a putative encapsulating protein. Antagonistic activity of the ~30 kDa encapsulating protein of Bl 1821L and Bl 1951during growth in broth exhibited bacterial autolytic activity. LIVE/DEAD staining of Bl 1821L cells after treatment with the ~30 kDa encapsulating protein of Bl 1821L substantiated the findings by showing 58.8% cells with the compromised cell membranes as compared to 37.5% cells in the control. Furthermore, antibacterial activity of the identified proteins of Bl 1821L was validated through gene expression in a Gram-positive bacterium Bacillus subtilis WB800N. Key Points • Gene encoding the 31.4 kDa antibacterial Linocin M18 protein was identified • It defined the autocidal activity of Linocin M18 (encapsulating) protein • Identified the possible killing mechanism of the encapsulins
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Hernández-García, Marta, de Aledo Manuel González, Manuel Ponce-Alonso, et al. "Simultaneous clonal spread of NDM-1–producing Pseudomonas aeruginosa ST773 from Ukrainian patients in the Netherlands and Spain." July 7, 2024. https://doi.org/10.1016/j.ijregi.2024.100415.
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<strong>Objectives: </strong>We describe the clonal spread of New Delhi metallo-β-lactamase (NDM) 1-producing <em>Pseudomonas aeruginosa</em> isolates belonging to the ST773 clone in Spain and the Netherlands, associated with the transfer of Ukrainian patients during the war. <strong>Methods: </strong>Between March and December 2022, nine NDM-1-producing <em>P. aeruginosa</em> ST773 isolates were recovered from nine Ukrainian patients evacuated to two Spanish (<em>n</em> = 3) and five Dutch (<em>n</em> = 6) hospitals. Antimicrobial susceptibility testing was studied (Sensititre, Microscan, EUCAST-2023). Whole genome sequencing (Illumina, Oxford-Nanopore) was used to analyze the genetic relatedness, the resistome, and the prophage content. <strong>Results: </strong>All NDM-1-producing <em>P. aeruginosa</em> ST773 isolates exhibited resistance to all tested antimicrobials except colistin, aztreonam, and cefiderocol. Genomic analysis revealed that all isolates had an identical resistome and a chromosomally encoded integrative conjugative element carrying the <em>bla</em> <sub>NDM-1</sub> gene. The core genome multilocus sequence typing and core genome single nucleotide polymorphisms analysis showed highly related isolates, irrespective of country of isolation, distant from other NDM-1-ST773 <em>P. aeruginosa</em> not collected in Ukraine. Both analysis revealed two closely related clusters, spanning the Spanish and Dutch isolates. In addition, a high content of prophages was identified in all strains, most of them in more than one isolate simultaneously, regardless of their origin country. Moreover, an identical phage tail-like bacteriocin cluster was identified in all NDM-1-ST773 <em>P. aeruginosa</em>. <strong>Conclusions: </strong>We report a clonal dissemination of NDM-producing <em>P. aeruginosa</em> ST773 to the Netherlands and Spain associated with patients from Ukraine. Our work highlights the importance of genomic surveillance and to understand the dynamics of resistance in multidrug-resistant bacteria after the transfer of patients from conflict zones. International collaboration is crucial to address global antimicrobial resistance.