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Leavitt JC, Woodbury BM, Gilcrease EB, Bridges CM, Teschke CM, Casjens SR. Bacteriophage P22 SieA-mediated superinfection exclusion. mBio 2024; 15:e0216923. [PMID: 38236051 PMCID: PMC10883804 DOI: 10.1128/mbio.02169-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2023] [Accepted: 11/10/2023] [Indexed: 01/19/2024] Open
Abstract
Many temperate phages encode prophage-expressed functions that interfere with superinfection of the host bacterium by external phages. Salmonella phage P22 has four such systems that are expressed from the prophage in a lysogen that are encoded by the c2 (repressor), gtrABC, sieA, and sieB genes. Here we report that the P22-encoded SieA protein is necessary and sufficient for exclusion by the SieA system and that it is an inner membrane protein that blocks DNA injection by P22 and its relatives, but has no effect on infection by other tailed phage types. The P22 virion injects its DNA through the host cell membranes and periplasm via a conduit assembled from three "ejection proteins" after their release from the virion. Phage P22 mutants that overcome the SieA block were isolated, and they have amino acid changes in the C-terminal regions of the gene 16 and 20 encoded ejection proteins. Three different single-amino acid changes in these proteins are required to obtain nearly full resistance to SieA. Hybrid P22 phages that have phage HK620 ejection protein genes are also partially resistant to SieA. There are three sequence types of extant phage-encoded SieA proteins that are less than 30% identical to one another, yet comparison of two of these types found no differences in phage target specificity. Our data strongly suggest a model in which the inner membrane protein SieA interferes with the assembly or function of the periplasmic gp20 and membrane-bound gp16 DNA delivery conduit.IMPORTANCEThe ongoing evolutionary battle between bacteria and the viruses that infect them is a critical feature of bacterial ecology on Earth. Viruses can kill bacteria by infecting them. However, when their chromosomes are integrated into a bacterial genome as a prophage, viruses can also protect the host bacterium by expressing genes whose products defend against infection by other viruses. This defense property is called "superinfection exclusion." A significant fraction of bacteria harbor prophages that encode such protective systems, and there are many different molecular strategies by which superinfection exclusion is mediated. This report is the first to describe the mechanism by which bacteriophage P22 SieA superinfection exclusion protein protects its host bacterium from infection by other P22-like phages. The P22 prophage-encoded inner membrane SieA protein prevents infection by blocking transport of superinfecting phage DNA across the inner membrane during injection.
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Affiliation(s)
- Justin C Leavitt
- School of Biological Sciences, University of Utah, Salt Lake City, Utah, USA
| | - Brianna M Woodbury
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, USA
| | - Eddie B Gilcrease
- Division of Microbiology and Immunology, Pathology Department, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Charles M Bridges
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, USA
| | - Carolyn M Teschke
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, USA
- Department of Chemistry, University of Connecticut, Storrs, Connecticut, USA
| | - Sherwood R Casjens
- School of Biological Sciences, University of Utah, Salt Lake City, Utah, USA
- Division of Microbiology and Immunology, Pathology Department, University of Utah School of Medicine, Salt Lake City, Utah, USA
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2
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Gunathilake KMD, Makumi A, Loignon S, Tremblay D, Labrie S, Svitek N, Moineau S. Diversity of Salmonella enterica phages isolated from chicken farms in Kenya. Microbiol Spectr 2024; 12:e0272923. [PMID: 38078723 PMCID: PMC10783031 DOI: 10.1128/spectrum.02729-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Accepted: 11/15/2023] [Indexed: 01/13/2024] Open
Abstract
IMPORTANCE Non-typhoidal Salmonella enterica infections are one of the leading causes of diarrhoeal diseases that spread to humans from animal sources such as poultry. Hence, keeping poultry farms free of Salmonella is essential for consumer safety and for a better yield of animal products. However, the emergence of antibiotic resistance due to over usage has sped up the search for alternative biocontrol methods such as the use of bacteriophages. Isolation and characterization of novel bacteriophages are key to adapt phage-based biocontrol applications. Here, we isolated and characterized Salmonella phages from samples collected at chicken farms and slaughterhouses in Kenya. The genomic characterization of these phage isolates revealed that they belong to four ICTV (International Committee on Taxonomy of Viruses) phage genera. All these phages are lytic and possibly suitable for biocontrol applications because no lysogenic genes or virulence factors were found in their genomes. Hence, we recommend further studies on these phages for their applications in Salmonella biocontrol.
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Affiliation(s)
- K. M. Damitha Gunathilake
- Département de biochimie, de microbiologie, et de bio-informatique, Faculté des sciences et de génie, Université Laval, Québec city, Quebec, Canada
| | - Angela Makumi
- International Livestock Research Institute (ILRI), Nairobi, Kenya
| | - Stéphanie Loignon
- Département de biochimie, de microbiologie, et de bio-informatique, Faculté des sciences et de génie, Université Laval, Québec city, Quebec, Canada
| | - Denise Tremblay
- Félix d'Hérelle Reference Center for Bacterial Viruses, Université Laval, Québec city, Quebec, Canada
| | | | - Nicholas Svitek
- International Livestock Research Institute (ILRI), Nairobi, Kenya
| | - Sylvain Moineau
- Département de biochimie, de microbiologie, et de bio-informatique, Faculté des sciences et de génie, Université Laval, Québec city, Quebec, Canada
- Félix d'Hérelle Reference Center for Bacterial Viruses, Université Laval, Québec city, Quebec, Canada
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Kondo K, Nakano S, Hisatsune J, Sugawara Y, Kataoka M, Kayama S, Sugai M, Kawano M. Characterization of 29 newly isolated bacteriophages as a potential therapeutic agent against IMP-6-producing Klebsiella pneumoniae from clinical specimens. Microbiol Spectr 2023; 11:e0476122. [PMID: 37724861 PMCID: PMC10581060 DOI: 10.1128/spectrum.04761-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 07/12/2023] [Indexed: 09/21/2023] Open
Abstract
Carbapenemase-producing Enterobacteriaceae (CPE) are one of the most detrimental species of antibiotic-resistant bacteria globally. Phage therapy has emerged as an effective strategy for the treatment of CPE infections. In western Japan, the rise of Klebsiella pneumoniae strains harboring the pKPI-6 plasmid encoding bla IMP-6 is of increasing concern. To address this challenge, we isolated 29 phages from Japanese sewage, specifically targeting 31 K. pneumoniae strains and one Escherichia coli strain harboring the pKPI-6 plasmid. Electron microscopy analysis revealed that among the 29 isolated phages, 21 (72.4%), 5 (17.2%), and 3 (10.3%) phages belonged to myovirus, siphovirus, and podovirus morphotypes, respectively. Host range analysis showed that 18 Slopekvirus strains within the isolated phages infected 25-26 K. pneumoniae strains, indicating that most of the isolated phages have a broad host range. Notably, K. pneumoniae strain Kp21 was exclusively susceptible to phage øKp_21, whereas Kp22 exhibited susceptibility to over 20 phages. Upon administering a phage cocktail composed of 10 phages, we observed delayed emergence of phage-resistant bacteria in Kp21 but not in Kp22. Intriguingly, phage-resistant Kp21 exhibited heightened sensitivity to other bacteriophages, indicating a "trade-off" for resistance to phage øKp_21. Our proposed phage set has an adequate number of phages to combat the K. pneumoniae strain prevalent in Japan, underscoring the potential of a well-designed phage cocktail in mitigating the occurrence of phage-resistant bacteria. IMPORTANCE The emergence of Klebsiella pneumoniae harboring the bla IMP-6 plasmid poses an escalating threat in Japan. In this study, we found 29 newly isolated bacteriophages that infect K. pneumoniae strains carrying the pKPI-6 plasmid from clinical settings in western Japan. Our phages exhibited a broad host range. We applied a phage cocktail treatment composed of 10 phages against two host strains, Kp21 and Kp22, which displayed varying phage susceptibility patterns. Although the phage cocktail delayed the emergence of phage-resistant Kp21, it was unable to hinder the emergence of phage-resistant Kp22. Moreover, the phage-resistant Kp21 became sensitive to other phages that were originally non-infective to the wild-type Kp21 strains. Our study highlights the potential of a well-tailored phage cocktail in reducing the occurrence of phage-resistant bacteria.
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Affiliation(s)
- Kohei Kondo
- Antimicrobial Resistance Research Center, National Institute of Infectious Diseases, Higashimurayama, Tokyo, Japan
| | - Satoshi Nakano
- Antimicrobial Resistance Research Center, National Institute of Infectious Diseases, Higashimurayama, Tokyo, Japan
| | - Junzo Hisatsune
- Antimicrobial Resistance Research Center, National Institute of Infectious Diseases, Higashimurayama, Tokyo, Japan
| | - Yo Sugawara
- Antimicrobial Resistance Research Center, National Institute of Infectious Diseases, Higashimurayama, Tokyo, Japan
| | - Michiyo Kataoka
- Department of Pathology, National Institute of Infectious Diseases, Toyama, Shinjuku-ku, Tokyo, Japan
| | - Shizuo Kayama
- Antimicrobial Resistance Research Center, National Institute of Infectious Diseases, Higashimurayama, Tokyo, Japan
| | - Motoyuki Sugai
- Antimicrobial Resistance Research Center, National Institute of Infectious Diseases, Higashimurayama, Tokyo, Japan
| | - Mitsuoki Kawano
- Department of Nutritional Sciences, Nakamura Gakuen University, Jonan-Ku, Fukuoka, Japan
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Leavitt JC, Woodbury BM, Gilcrease EB, Bridges CM, Teschke CM, Casjens SR. Bacteriophage P22 SieA mediated superinfection exclusion. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.15.553423. [PMID: 37645741 PMCID: PMC10461980 DOI: 10.1101/2023.08.15.553423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Many temperate phages encode prophage-expressed functions that interfere with superinfection of the host bacterium by external phages. Salmonella phage P22 has four such systems that are expressed from the prophage in a lysogen that are encoded by the c2 (repressor), gtrABC, sieA, and sieB genes. Here we report that the P22-encoded SieA protein is the only phage protein required for exclusion by the SieA system, and that it is an inner membrane protein that blocks DNA injection by P22 and its relatives, but has no effect on infection by other tailed phage types. The P22 virion injects its DNA through the host cell membranes and periplasm via a conduit assembled from three "ejection proteins" after their release from the virion. Phage P22 mutants were isolated that overcome the SieA block, and they have amino acid changes in the C-terminal regions of the gene 16 and 20 encoded ejection proteins. Three different single amino acid changes in these proteins are required to obtain nearly full resistance to SieA. Hybrid P22 phages that have phage HK620 ejection protein genes are also partially resistant to SieA. There are three sequence types of extant phage-encoded SieA proteins that are less than 30% identical to one another, yet comparison of two of these types found no differences in target specificity. Our data are consistent with a model in which the inner membrane protein SieA interferes with the assembly or function of the periplasmic gp20 and membrane-bound gp16 DNA delivery conduit.
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Affiliation(s)
- Justin C. Leavitt
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112 USA
- Current address: Green Raccoon Scientific, Gunlock UT 84733 USA
| | - Brianna M. Woodbury
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269, USA
- Current address: York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, UK
| | - Eddie B. Gilcrease
- Division of Microbiology and Immunology, Pathology Department, University of Utah School of Medicine, Salt Lake City, UT 84112 USA
- Current address: Department of Civil and Environmental Engineering, University of Utah, Salt Lake City, UT 84112 USA
| | - Charles M. Bridges
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269, USA
| | - Carolyn M. Teschke
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269, USA
- Department of Chemistry, University of Connecticut, Storrs, CT 06269 USA
| | - Sherwood R. Casjens
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112 USA
- Division of Microbiology and Immunology, Pathology Department, University of Utah School of Medicine, Salt Lake City, UT 84112 USA
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Elankumuran P, Browning GF, Marenda MS, Kidsley A, Osman M, Haenni M, Johnson JR, Trott DJ, Reid CJ, Djordjevic SP. Identification of genes influencing the evolution of Escherichia coli ST372 in dogs and humans. Microb Genom 2023; 9:mgen000930. [PMID: 36752777 PMCID: PMC9997745 DOI: 10.1099/mgen.0.000930] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
Abstract
ST372 are widely reported as the major Escherichia coli sequence type in dogs globally. They are also a sporadic cause of extraintestinal infections in humans. Despite this, it is unknown whether ST372 strains from dogs and humans represent shared or distinct populations. Furthermore, little is known about genomic traits that might explain the prominence of ST372 in dogs or presence in humans. To address this, we applied a variety of bioinformatics analyses to a global collection of 407 ST372 E. coli whole-genome sequences to characterize their epidemiological features, population structure and associated accessory genomes. We confirm that dogs are the dominant host of ST372 and that clusters within the population structure exhibit distinctive O:H types. One phylogenetic cluster, 'cluster M', comprised almost half of the sequences and showed the divergence of two human-restricted clades that carried different O:H types to the remainder of the cluster. We also present evidence supporting transmission between dogs and humans within different clusters of the phylogeny, including M. We show that multiple acquisitions of the pdu propanediol utilization operon have occurred in clusters dominated by isolates of canine source, possibly linked to diet, whereas loss of the pdu operon and acquisition of K antigen virulence genes characterize human-restricted lineages.
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Affiliation(s)
- Paarthiphan Elankumuran
- Australian Institute for Microbiology and Infection, School of Life Sciences, Faculty of Science, University of Technology Sydney, Ultimo, NSW, Australia
| | - Glenn F. Browning
- Asia-Pacific Centre for Animal Health, Department of Veterinary Biosciences, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville and Werribee, Victoria, Australia
| | - Marc S. Marenda
- Asia-Pacific Centre for Animal Health, Department of Veterinary Biosciences, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville and Werribee, Victoria, Australia
| | - Amanda Kidsley
- Australian Centre for Antimicrobial Resistance Ecology, School of Animal and Veterinary Sciences, University of Adelaide, Roseworthy, Australia
| | - Marwan Osman
- Laboratoire Microbiologie Santé et Environnement, Doctoral School of Sciences and Technology, Faculty of Public Health, Lebanese University, Tripoli, Lebanon
- Department of Public and Ecosystem Health, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Marisa Haenni
- ANSES, Université de Lyon, Unité Antibiorésistance et Virulence Bactériennes, Lyon, France
| | | | - Darren J. Trott
- Australian Centre for Antimicrobial Resistance Ecology, School of Animal and Veterinary Sciences, University of Adelaide, Roseworthy, Australia
| | - Cameron J. Reid
- Australian Institute for Microbiology and Infection, School of Life Sciences, Faculty of Science, University of Technology Sydney, Ultimo, NSW, Australia
| | - Steven P. Djordjevic
- Australian Institute for Microbiology and Infection, School of Life Sciences, Faculty of Science, University of Technology Sydney, Ultimo, NSW, Australia
- *Correspondence: Steven P. Djordjevic,
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6
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O-Acetylation of Capsular Polysialic Acid Enables Escherichia coli K1 Escaping from Siglec-Mediated Innate Immunity and Lysosomal Degradation of E. coli-Containing Vacuoles in Macrophage-Like Cells. Microbiol Spectr 2021; 9:e0039921. [PMID: 34878295 PMCID: PMC8653822 DOI: 10.1128/spectrum.00399-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Escherichia coli K1 causes bacteremia and meningitis in human neonates. The K1 capsule, an α2,8-linked polysialic acid (PSA) homopolymer, is its essential virulence factor. PSA is usually partially modified by O-acetyl groups. It is known that O-acetylation alters the antigenicity of PSA, but its impact on the interactions between E. coli K1 and host cells is unclear. In this study, a phase variant was obtained by passage of E. coli K1 parent strain, which expressed a capsule with 44% O-acetylation whereas the capsule of the parent strain has only 3%. The variant strain showed significantly reduced adherence and invasion to macrophage-like cells in comparison to the parent strain. Furthermore, we found that O-acetylation of PSA enhanced the modulation of trafficking of E. coli-containing vacuoles (ECV), enabling them to avoid fusing with lysosomes in these cells. Intriguingly, by using quartz crystal microbalance, we demonstrated that the PSA purified from the parent strain interacted with human sialic acid-binding immunoglobulin-like lectins (Siglecs), including Siglec-5, Siglec-7, Siglec-11, and Siglec-14. However, O-acetylated PSA from the variant interacted much less and also suppressed the production of Siglec-mediated proinflammatory cytokines. The adherence of the parent strain to human macrophage-like cells was significantly blocked by monoclonal antibodies against Siglec-11 and Siglec-14. Furthermore, the variant strain caused increased bacteremia and higher lethality in neonatal mice compared to the parent strain. These data elucidate that O-acetylation of K1 capsule enables E. coli to escape from Siglec-mediated innate immunity and lysosomal degradation; therefore, it is a strategy used by E. coli K1 to regulate its virulence. IMPORTANCEEscherichia coli K1 is a leading cause of neonatal meningitis. The mortality and morbidity of this disease remain significantly high despite antibiotic therapy. One major limitation on advances in prevention and therapy for meningitis is an incomplete understanding of its pathogenesis. E. coli K1 is surrounded by PSA, which is observed to have high-frequency variation of O-acetyl modification. Here, we present an in-depth study of the function of O-acetylation in PSA at each stage of host-pathogen interaction. We found that a high level of O-acetylation significantly interfered with Siglec-mediated bacterial adherence to macrophage-like cells, and blunted the proinflammatory response. Furthermore, the O-acetylation of PSA modulated the trafficking of ECVs to prevent them from fusing with lysosomes, enabling them to escape degradation by lysozymes within these cells. Elucidating how subtle modification of the capsule enhances bacterial defenses against host innate immunity will enable the future development of effective drugs or vaccines against infection by E. coli K1.
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7
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McDonald ND, Boyd EF. Structural and Biosynthetic Diversity of Nonulosonic Acids (NulOs) That Decorate Surface Structures in Bacteria. Trends Microbiol 2021; 29:142-157. [PMID: 32950378 PMCID: PMC7855311 DOI: 10.1016/j.tim.2020.08.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 08/14/2020] [Accepted: 08/19/2020] [Indexed: 12/12/2022]
Abstract
Nonulosonic acids (NulOs) are a diverse family of 9-carbon α-keto acid sugars that are involved in a wide range of functions across all branches of life. The family of NulOs includes the sialic acids as well as the prokaryote-specific NulOs. Select bacteria biosynthesize the sialic acid N-acetylneuraminic acid (Neu5Ac), and the ability to produce this sugar and its subsequent incorporation into cell-surface structures is implicated in a variety of bacteria-host interactions. Furthermore, scavenging of sialic acid from the environment for energy has been characterized across a diverse group of bacteria, mainly human commensals and pathogens. In addition to sialic acid, bacteria have the ability to biosynthesize prokaryote-specific NulOs, of which there are several known isomers characterized. These prokaryotic NulOs are similar in structure to Neu5Ac but little is known regarding their role in bacterial physiology. Here, we discuss the diversity in structure, the biosynthesis pathways, and the functions of bacteria-specific NulOs. These carbohydrates are phylogenetically widespread among bacteria, with numerous structurally unique modifications recognized. Despite the diversity in structure, the NulOs are involved in similar functions such as motility, biofilm formation, host colonization, and immune evasion.
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Affiliation(s)
- Nathan D McDonald
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - E Fidelma Boyd
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA.
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8
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Liu Y, Gong Q, Qian X, Li D, Zeng H, Li Y, Xue F, Ren J, Zhu Ge X, Tang F, Dai J. Prophage phiv205-1 facilitates biofilm formation and pathogenicity of avian pathogenic Escherichia coli strain DE205B. Vet Microbiol 2020; 247:108752. [PMID: 32768206 DOI: 10.1016/j.vetmic.2020.108752] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 06/10/2020] [Accepted: 06/10/2020] [Indexed: 12/29/2022]
Abstract
Avian colibacillosis caused by avian pathogenic Escherichia coli (APEC) causes significant economic losses to the poultry industry worldwide and is also a leading potential threat to human health. Bacteriophages integrate into the host bacterial chromosome, and are an important source of genetic variation and have a major impact on bacterial evolution. Previously, we predicted prophage phiv205-1 in APEC strain DE205B. Here, to determine the function of prophage phiv205-1, we constructed the prophage deletion mutant DE205BΔphiv205-1. Compared with the wild-type (WT) APEC strain DE205B, the adherence and invasive abilities of DE205BΔphiv205-1 were reduced by 41.88 %(P < 0.05). Further, the mutant strain had 52.38 % reduced biofilm formation compared with the WT strain (P < 0.001). Chick challenge showed that the median lethal dose (LD50) of the mutant strain and WT strain was 3.13 × 105 colony-forming units (CFU) and 3.86 × 104 CFU, respectively, indicating that the mutant strain had decreased virulence compared with the WT strain. Furthermore, in vivo studies showed that, compared with the WT strain, DE205BΔphiv205-1 bacterial loads were reduced by 1.6-fold (P < 0.05) and 4.8-fold (P < 0.001) in the lungs and brains, respectively, of the infected chicks. In conclusion, the prophage phiv205-1 contributes to the virulence of APEC strain DE205B by facilitating the adherence, biofilm formation, and colonization abilities of its host strain.
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Affiliation(s)
- Yun Liu
- MOE Joint International Research Laboratory of Animal Health and Food Safety, Key Laboratory of Animal Bacteriology, Ministry of Agriculture, College ofVeterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Qianwen Gong
- MOE Joint International Research Laboratory of Animal Health and Food Safety, Key Laboratory of Animal Bacteriology, Ministry of Agriculture, College ofVeterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Xinjie Qian
- MOE Joint International Research Laboratory of Animal Health and Food Safety, Key Laboratory of Animal Bacteriology, Ministry of Agriculture, College ofVeterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Dezhi Li
- MOE Joint International Research Laboratory of Animal Health and Food Safety, Key Laboratory of Animal Bacteriology, Ministry of Agriculture, College ofVeterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Hang Zeng
- MOE Joint International Research Laboratory of Animal Health and Food Safety, Key Laboratory of Animal Bacteriology, Ministry of Agriculture, College ofVeterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yihao Li
- MOE Joint International Research Laboratory of Animal Health and Food Safety, Key Laboratory of Animal Bacteriology, Ministry of Agriculture, College ofVeterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Feng Xue
- MOE Joint International Research Laboratory of Animal Health and Food Safety, Key Laboratory of Animal Bacteriology, Ministry of Agriculture, College ofVeterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Jianluan Ren
- MOE Joint International Research Laboratory of Animal Health and Food Safety, Key Laboratory of Animal Bacteriology, Ministry of Agriculture, College ofVeterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Xiangkai Zhu Ge
- MOE Joint International Research Laboratory of Animal Health and Food Safety, Key Laboratory of Animal Bacteriology, Ministry of Agriculture, College ofVeterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China
| | - Fang Tang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, Key Laboratory of Animal Bacteriology, Ministry of Agriculture, College ofVeterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China.
| | - Jianjun Dai
- MOE Joint International Research Laboratory of Animal Health and Food Safety, Key Laboratory of Animal Bacteriology, Ministry of Agriculture, College ofVeterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China.
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9
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Casjens SR, Grose JH. Contributions of P2- and P22-like prophages to understanding the enormous diversity and abundance of tailed bacteriophages. Virology 2016; 496:255-276. [PMID: 27372181 DOI: 10.1016/j.virol.2016.05.022] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 05/25/2016] [Accepted: 05/26/2016] [Indexed: 11/24/2022]
Abstract
We identified 9371 tailed phage prophages of 20 known types in reported complete genome sequences of 3298 bacteria in the Salmonella genus. These include 4758 P2 type and 744 P22 type prophages. The latter prophage types were found in the genome sequences of 127 and 24 bacterial host genera, increasing the known host ranges of phages in these groups by 114 and 20 genera, respectively. These prophage nucleotide sequences displayed much more diversity than was previously known from the 48 P2 and 24 P22 type authentic phages whose genomes have been sequenced. More detailed analysis of these prophage sequences indicated that major capsid protein (MCP) gene exchange between tailed phage clusters or types is extremely rare and that P22 prophage-encoded tailspikes correspond perfectly with their hosts' surface polysaccharide structure; thus, MCP and tailspike sequences accurately predict tailed phage type (and thus lifestyle) and host cell surface polysaccharide structure, respectively.
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Affiliation(s)
- Sherwood R Casjens
- Division of Microbiology and Immunology, Department of Pathology, University of Utah School of Medicine, University of Utah, Salt Lake City, UT 84112, United States; Department of Biology, University of Utah, Salt Lake City, UT 84112, United States.
| | - Julianne H Grose
- Microbiology and Molecular Biology Department, Brigham Young University, Provo, UT 84602, United States.
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10
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Parent KN, Tang J, Cardone G, Gilcrease EB, Janssen ME, Olson NH, Casjens SR, Baker TS. Three-dimensional reconstructions of the bacteriophage CUS-3 virion reveal a conserved coat protein I-domain but a distinct tailspike receptor-binding domain. Virology 2014; 464-465:55-66. [PMID: 25043589 DOI: 10.1016/j.virol.2014.06.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Revised: 06/12/2014] [Accepted: 06/15/2014] [Indexed: 01/21/2023]
Abstract
CUS-3 is a short-tailed, dsDNA bacteriophage that infects serotype K1 Escherichia coli. We report icosahedrally averaged and asymmetric, three-dimensional, cryo-electron microscopic reconstructions of the CUS-3 virion. Its coat protein structure adopts the "HK97-fold" shared by other tailed phages and is quite similar to that in phages P22 and Sf6 despite only weak amino acid sequence similarity. In addition, these coat proteins share a unique extra external domain ("I-domain"), suggesting that the group of P22-like phages has evolved over a very long time period without acquiring a new coat protein gene from another phage group. On the other hand, the morphology of the CUS-3 tailspike differs significantly from that of P22 or Sf6, but is similar to the tailspike of phage K1F, a member of the extremely distantly related T7 group of phages. We conclude that CUS-3 obtained its tailspike gene from a distantly related phage quite recently.
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Affiliation(s)
- Kristin N Parent
- Department of Chemistry & Biochemistry, University of California, San Diego, La Jolla, CA 92093-0378, United States.
| | - Jinghua Tang
- Department of Chemistry & Biochemistry, University of California, San Diego, La Jolla, CA 92093-0378, United States
| | - Giovanni Cardone
- Department of Chemistry & Biochemistry, University of California, San Diego, La Jolla, CA 92093-0378, United States
| | - Eddie B Gilcrease
- University of Utah School of Medicine, Division of Microbiology and Immunology, Department of Pathology, Salt Lake City, UT 84112, United States
| | - Mandy E Janssen
- Department of Chemistry & Biochemistry, University of California, San Diego, La Jolla, CA 92093-0378, United States
| | - Norman H Olson
- Department of Chemistry & Biochemistry, University of California, San Diego, La Jolla, CA 92093-0378, United States
| | - Sherwood R Casjens
- University of Utah School of Medicine, Division of Microbiology and Immunology, Department of Pathology, Salt Lake City, UT 84112, United States.
| | - Timothy S Baker
- Department of Chemistry & Biochemistry, University of California, San Diego, La Jolla, CA 92093-0378, United States; University of California, San Diego, Division of Biological Sciences, La Jolla, CA, 92093, United States.
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11
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Peris-Bondia F, Muraille E, Van Melderen L. Complete Genome Sequence of the Escherichia coli PMV-1 Strain, a Model Extraintestinal Pathogenic E. coli Strain Used for Host-Pathogen Interaction Studies. GENOME ANNOUNCEMENTS 2013; 1:e00913-13. [PMID: 24158560 PMCID: PMC3813190 DOI: 10.1128/genomea.00913-13] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 10/02/2013] [Indexed: 01/15/2023]
Abstract
Escherichia coli is a highly versatile species, causing diverse intestinal and extraintestinal infections. Here, we present the complete genome sequence of PMV-1, an O18:K1 extraintestinal pathogenic E. coli (ExPEC) strain that is used as a model for peritonitis in mice and was useful for deciphering the innate immune response triggered by ExPEC infections.
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Affiliation(s)
- Francesc Peris-Bondia
- Laboratoire de Génétique et Physiologie Bactérienne, IBMM, Faculté des Sciences, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Eric Muraille
- Laboratoire de Parasitologie, Faculté de Médecine, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Laurence Van Melderen
- Laboratoire de Génétique et Physiologie Bactérienne, IBMM, Faculté des Sciences, Université Libre de Bruxelles (ULB), Brussels, Belgium
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12
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Zhou K, Aertsen A, Michiels CW. The role of variable DNA tandem repeats in bacterial adaptation. FEMS Microbiol Rev 2013; 38:119-41. [PMID: 23927439 DOI: 10.1111/1574-6976.12036] [Citation(s) in RCA: 100] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Revised: 07/13/2013] [Accepted: 07/26/2013] [Indexed: 01/05/2023] Open
Abstract
DNA tandem repeats (TRs), also designated as satellite DNA, are inter- or intragenic nucleotide sequences that are repeated two or more times in a head-to-tail manner. Because TR tracts are prone to strand-slippage replication and recombination events that cause the TR copy number to increase or decrease, loci containing TRs are hypermutable. An increasing number of examples illustrate that bacteria can exploit this instability of TRs to reversibly shut down or modulate the function of specific genes, allowing them to adapt to changing environments on short evolutionary time scales without an increased overall mutation rate. In this review, we discuss the prevalence and distribution of inter- and intragenic TRs in bacteria and the mechanisms of their instability. In addition, we review evidence demonstrating a role of TR variations in bacterial adaptation strategies, ranging from immune evasion and tissue tropism to the modulation of environmental stress tolerance. Nevertheless, while bioinformatic analysis reveals that most bacterial genomes contain a few up to several dozens of intra- and intergenic TRs, only a small fraction of these have been functionally studied to date.
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Affiliation(s)
- Kai Zhou
- Department of Microbial and Molecular Systems (M²S), Faculty of Bioscience Engineering, Laboratory of Food Microbiology and Leuven Food Science and Nutrition Research Centre (LFoRCe), KU Leuven, Leuven, Belgium
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13
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McCallin S, Alam Sarker S, Barretto C, Sultana S, Berger B, Huq S, Krause L, Bibiloni R, Schmitt B, Reuteler G, Brüssow H. Safety analysis of a Russian phage cocktail: from metagenomic analysis to oral application in healthy human subjects. Virology 2013; 443:187-96. [PMID: 23755967 DOI: 10.1016/j.virol.2013.05.022] [Citation(s) in RCA: 164] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Revised: 03/04/2013] [Accepted: 05/06/2013] [Indexed: 02/06/2023]
Abstract
Phage therapy has a long tradition in Eastern Europe, where preparations are comprised of complex phage cocktails whose compositions have not been described. We investigated the composition of a phage cocktail from the Russian pharmaceutical company Microgen targeting Escherichia coli/Proteus infections. Electron microscopy identified six phage types, with numerically T7-like phages dominating over T4-like phages. A metagenomic approach using taxonomical classification, reference mapping and de novo assembly identified 18 distinct phage types, including 7 genera of Podoviridae, 2 established and 2 proposed genera of Myoviridae, and 2 genera of Siphoviridae. De novo assembly yielded 7 contigs greater than 30 kb, including a 147-kb Myovirus genome and a 42-kb genome of a potentially new phage. Bioinformatic analysis did not reveal undesired genes and a small human volunteer trial did not associate adverse effects with oral phage exposure.
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Affiliation(s)
- Shawna McCallin
- Nestlé Research Centre, Nestec Ltd, Vers-chez-les-Blanc, CH-1000 Lausanne 26, Switzerland.
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14
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Steenbergen SM, Vimr ER. Chromatographic analysis of the Escherichia coli polysialic acid capsule. Methods Mol Biol 2013; 966:109-20. [PMID: 23299731 DOI: 10.1007/978-1-62703-245-2_7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Polysialic acid capsules are the major virulence factors in Escherichia coliK1, K92, and groups B and C meningococci. The sialic acid monomers (2-keto-3-deoxy-5-acetamido-7,8,9-D-glycero-D-galacto-nonulosonic acids) comprising these homopolymeric polysaccharide chains can be selectively modified with 1,2-diamino-4,5-methylenedioxy-benzene to produce highly fluorescent quinoxalinone derivatives distinguished by their elution times during reverse phase chromatography. Here, we describe methods to release the constituent capsular polysialic acid monomers, and to detect and quantify them by sensitive fluorometry. There are relatively few 2-keto acids in bacteria, making it possible to rapidly analyze samples even without prior purification of capsular polysaccharides.
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Affiliation(s)
- Susan M Steenbergen
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
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15
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Vehicles, replicators, and intercellular movement of genetic information: evolutionary dissection of a bacterial cell. INTERNATIONAL JOURNAL OF EVOLUTIONARY BIOLOGY 2012; 2012:874153. [PMID: 22567533 PMCID: PMC3332184 DOI: 10.1155/2012/874153] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Revised: 02/06/2012] [Accepted: 02/08/2012] [Indexed: 11/18/2022]
Abstract
Prokaryotic biosphere is vastly diverse in many respects. Any given bacterial cell may harbor in different combinations viruses, plasmids, transposons, and other genetic elements along with their chromosome(s). These agents interact in complex environments in various ways causing multitude of phenotypic effects on their hosting cells. In this discussion I perform a dissection for a bacterial cell in order to simplify the diversity into components that may help approach the ocean of details in evolving microbial worlds. The cell itself is separated from all the genetic replicators that use the cell vehicle for preservation and propagation. I introduce a classification that groups different replicators according to their horizontal movement potential between cells and according to their effects on the fitness of their present host cells. The classification is used to discuss and improve the means by which we approach general evolutionary tendencies in microbial communities. Moreover, the classification is utilized as a tool to help formulating evolutionary hypotheses and to discuss emerging bacterial pathogens as well as to promote understanding on the average phenotypes of different replicators in general. It is also discussed that any given biosphere comprising prokaryotic cell vehicles and genetic replicators may naturally evolve to have horizontally moving replicators of various types.
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16
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Parent KN, Gilcrease EB, Casjens SR, Baker TS. Structural evolution of the P22-like phages: comparison of Sf6 and P22 procapsid and virion architectures. Virology 2012; 427:177-88. [PMID: 22386055 DOI: 10.1016/j.virol.2012.01.040] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2011] [Revised: 01/10/2012] [Accepted: 01/30/2012] [Indexed: 01/07/2023]
Abstract
Coat proteins of tailed, dsDNA phages and in herpesviruses include a conserved core similar to the bacteriophage HK97 subunit. This core is often embellished with other domains such as the telokin Ig-like domain of phage P22. Eighty-six P22-like phages and prophages with sequenced genomes share a similar set of virion assembly genes and, based on comparisons of twelve viral assembly proteins (structural and assembly/packaging chaperones), these phages are classified into three groups (P22-like, Sf6-like, and CUS-3-like). We used cryo-electron microscopy and 3D image reconstruction to determine the structures of Sf6 procapsids and virions (~7Å resolution), and the structure of the entire, asymmetric Sf6 virion (16-Å resolution). The Sf6 coat protein is similar to that of P22 yet it has differences in the telokin domain and in its overall quaternary organization. Thermal stability and agarose gel experiments show that Sf6 virions are slightly less stable than those of P22. Finally, bacterial host outer membrane proteins A and C were identified in lipid vesicles that co-purify with Sf6 particles, but are not components of the capsid.
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Affiliation(s)
- Kristin N Parent
- University of California, San Diego, Department of Chemistry & Biochemistry, La Jolla, CA 92093, USA
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17
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Casjens SR, Molineux IJ. Short noncontractile tail machines: adsorption and DNA delivery by podoviruses. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 726:143-79. [PMID: 22297513 DOI: 10.1007/978-1-4614-0980-9_7] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Tailed dsDNA bacteriophage virions bind to susceptible cells with the tips of their tails and then deliver their DNA through the tail into the cells to initiate infection. This chapter discusses what is known about this process in the short-tailed phages (Podoviridae). Their short tails require that many of these virions adsorb to the outer layers of the cell and work their way down to the outer membrane surface before releasing their DNA. Interestingly, the receptor-binding protein of many short-tailed phages (and some with long tails) has an enzymatic activity that cleaves their polysaccharide receptors. Reversible adsorption and irreversible adsorption to primary and secondary receptors are discussed, including how sequence divergence in tail fiber and tailspike proteins leads to different host specificities. Upon reaching the outer membrane of Gram-negative cells, some podoviral tail machines release virion proteins into the cell that help the DNA efficiently traverse the outer layers of the cell and/or prepare the cell cytoplasm for phage genome arrival. Podoviruses utilize several rather different variations on this theme. The virion DNA is then released into the cell; the energetics of this process is discussed. Phages like T7 and N4 deliver their DNA relatively slowly, using enzymes to pull the genome into the cell. At least in part this mechanism ensures that genes in late-entering DNA are not expressed at early times. On the other hand, phages like P22 probably deliver their DNA more rapidly so that it can be circularized before the cascade of gene expression begins.
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Affiliation(s)
- Sherwood R Casjens
- Pathology Department, University of Utah School of Medicine, Salt Lake City, UT 84112, USA.
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18
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Crystal structure analysis of the polysialic acid specific O-acetyltransferase NeuO. PLoS One 2011; 6:e17403. [PMID: 21390252 PMCID: PMC3046976 DOI: 10.1371/journal.pone.0017403] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Accepted: 01/30/2011] [Indexed: 11/19/2022] Open
Abstract
The major virulence factor of the neuroinvasive pathogen Escherichia coli K1 is the K1 capsule composed of α2,8-linked polysialic acid (polySia). K1 strains harboring the CUS-3 prophage modify their capsular polysaccharide by phase-variable O-acetlyation, a step that is associated with increased virulence. Here we present the crystal structure of the prophage-encoded polysialate O-acetyltransferase NeuO. The homotrimeric enzyme belongs to the left-handed β-helix (LβH) family of acyltransferases and is characterized by an unusual funnel-shaped outline. Comparison with other members of the LβH family allowed the identification of active site residues and proposal of a catalytic mechanism and highlighted structural characteristics of polySia specific O-acetyltransferases. As a unique feature of NeuO, the enzymatic activity linearly increases with the length of the N-terminal poly-ψ-domain which is composed of a variable number of tandem copies of an RLKTQDS heptad. Since the poly-ψ-domain was not resolved in the crystal structure it is assumed to be unfolded in the apo-enyzme.
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19
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Casjens SR, Thuman-Commike PA. Evolution of mosaically related tailed bacteriophage genomes seen through the lens of phage P22 virion assembly. Virology 2011; 411:393-415. [PMID: 21310457 DOI: 10.1016/j.virol.2010.12.046] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Revised: 12/20/2010] [Accepted: 12/23/2010] [Indexed: 01/06/2023]
Abstract
The mosaic composition of the genomes of dsDNA tailed bacteriophages (Caudovirales) is well known. Observations of this mosaicism have generally come from comparisons of small numbers of often rather distantly related phages, and little is known about the frequency or detailed nature of the processes that generate this kind of diversity. Here we review and examine the mosaicism within fifty-seven clusters of virion assembly genes from bacteriophage P22 and its "close" relatives. We compare these orthologous gene clusters, discuss their surprising diversity and document horizontal exchange of genetic information between subgroups of the P22-like phages as well as between these phages and other phage types. We also point out apparent restrictions in the locations of mosaic sequence boundaries in this gene cluster. The relatively large sample size and the fact that phage P22 virion structure and assembly are exceptionally well understood make the conclusions especially informative and convincing.
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Affiliation(s)
- Sherwood R Casjens
- Pathology Department, University of Utah School of Medicine, Salt Lake City, UT 84112, USA.
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20
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Schauer R, Srinivasan GV, Wipfler D, Kniep B, Schwartz-Albiez R. O-Acetylated sialic acids and their role in immune defense. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2011; 705:525-48. [PMID: 21618128 PMCID: PMC7123180 DOI: 10.1007/978-1-4419-7877-6_28] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Roland Schauer
- Biochemisches Institut, Christian-Albrechts-Universität, Olshausenstr 40, D-24098 Kiel, Germany.
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21
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Panis G, Duverger Y, Courvoisier-Dezord E, Champ S, Talla E, Ansaldi M. Tight regulation of the intS gene of the KplE1 prophage: a new paradigm for integrase gene regulation. PLoS Genet 2010; 6. [PMID: 20949106 PMCID: PMC2951348 DOI: 10.1371/journal.pgen.1001149] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2010] [Accepted: 09/02/2010] [Indexed: 11/18/2022] Open
Abstract
Temperate phages have the ability to maintain their genome in their host, a process called lysogeny. For most, passive replication of the phage genome relies on integration into the host's chromosome and becoming a prophage. Prophages remain silent in the absence of stress and replicate passively within their host genome. However, when stressful conditions occur, a prophage excises itself and resumes the viral cycle. Integration and excision of phage genomes are mediated by regulated site-specific recombination catalyzed by tyrosine and serine recombinases. In the KplE1 prophage, site-specific recombination is mediated by the IntS integrase and the TorI recombination directionality factor (RDF). We previously described a sub-family of temperate phages that is characterized by an unusual organization of the recombination module. Consequently, the attL recombination region overlaps with the integrase promoter, and the integrase and RDF genes do not share a common activated promoter upon lytic induction as in the lambda prophage. In this study, we show that the intS gene is tightly regulated by its own product as well as by the TorI RDF protein. In silico analysis revealed that overlap of the attL region with the integrase promoter is widely encountered in prophages present in prokaryotic genomes, suggesting a general occurrence of negatively autoregulated integrase genes. The prediction that these integrase genes are negatively autoregulated was biologically assessed by studying the regulation of several integrase genes from two different Escherichia coli strains. Our results suggest that the majority of tRNA-associated integrase genes in prokaryotic genomes could be autoregulated and that this might be correlated with the recombination efficiency as in KplE1. The consequences of this unprecedented regulation for excessive recombination are discussed.
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Affiliation(s)
- Gaël Panis
- Laboratoire de Chimie Bactérienne, CNRS UPR9043, Institut de Microbiologie de la Méditerranée, Marseille, France
- Aix-Marseille Université, Marseille, France
| | - Yohann Duverger
- Laboratoire de Chimie Bactérienne, CNRS UPR9043, Institut de Microbiologie de la Méditerranée, Marseille, France
| | - Elise Courvoisier-Dezord
- Laboratoire de Chimie Bactérienne, CNRS UPR9043, Institut de Microbiologie de la Méditerranée, Marseille, France
| | - Stéphanie Champ
- Laboratoire de Chimie Bactérienne, CNRS UPR9043, Institut de Microbiologie de la Méditerranée, Marseille, France
| | - Emmanuel Talla
- Laboratoire de Chimie Bactérienne, CNRS UPR9043, Institut de Microbiologie de la Méditerranée, Marseille, France
- Aix-Marseille Université, Marseille, France
- * E-mail: (MA); (ET)
| | - Mireille Ansaldi
- Laboratoire de Chimie Bactérienne, CNRS UPR9043, Institut de Microbiologie de la Méditerranée, Marseille, France
- Aix-Marseille Université, Marseille, France
- * E-mail: (MA); (ET)
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22
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Panis G, Duverger Y, Champ S, Ansaldi M. Protein binding sites involved in the assembly of the KplE1 prophage intasome. Virology 2010; 404:41-50. [PMID: 20494389 DOI: 10.1016/j.virol.2010.04.027] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2010] [Revised: 02/24/2010] [Accepted: 04/27/2010] [Indexed: 11/25/2022]
Abstract
The organization of the recombination regions of the KplE1 prophage in Escherichia coli K12 differs from that observed in the lambda prophage. Indeed, the binding sites characterized for the IntS integrase, the TorI recombination directionality factor (RDF) and the integration host factor (IHF) vary in number, spacing and orientation on the attL and attR regions. In this paper, we performed site-directed mutagenesis of the recombination sites to decipher if all sites are essential for the site-specific recombination reaction and how the KplE1 intasome is assembled. We also show that TorI and IntS form oligomers that are stabilized in the presence of their target DNA. Moreover, we found that IHF is the only nucleoid associated protein (NAP) involved in KplE1 recombination, although it is dispensable. This is consistent with the presence of only one functional IHF site on attR and none on attL.
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Affiliation(s)
- Gaël Panis
- Laboratoire de Chimie Bactérienne CNRS UPR9043, Institut de Microbiologie de la Méditerranée, Marseille Cedex 20, France
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23
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Ferrero MA, Aparicio LR. Biosynthesis and production of polysialic acids in bacteria. Appl Microbiol Biotechnol 2010; 86:1621-35. [PMID: 20349183 DOI: 10.1007/s00253-010-2531-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2010] [Revised: 02/25/2010] [Accepted: 02/25/2010] [Indexed: 01/30/2023]
Abstract
Polysialic acids (PA) are protective capsular sialohomopolymers present in some bacteria which can invade the mammalian host and cause lethal bacteremia and meningitis. Biosynthesis and translocation of PA to the cell surface are equivalent in different species and bacterial strains which are produced. The diversity in PA structure is derived from the PA linkages and is a consequence of the specific sialyltransferase activities. The monomer acetylation and the polymer length could be important factors in the potential virulence. In vivo PA production is affected by different physical and chemical factors. The temperature of cellular growth strictly regulates PA genesis through a molecular complex and multifactorial mechanism that operate to transcription level.
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Affiliation(s)
- Miguel Angel Ferrero
- Departamento de Biología Molecular, Universidad de León, Campus de Vegazana, 24071, León, Spain.
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24
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Mordhorst IL, Claus H, Ewers C, Lappann M, Schoen C, Elias J, Batzilla J, Dobrindt U, Wieler LH, Bergfeld AK, Mühlenhoff M, Vogel U. O-acetyltransferase geneneuOis segregated according to phylogenetic background and contributes to environmental desiccation resistance inEscherichia coliK1. Environ Microbiol 2009; 11:3154-65. [DOI: 10.1111/j.1462-2920.2009.02019.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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25
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Abstract
The capsule is a cell surface structure composed of long-chain polysaccharides that envelops many isolates of Escherichia coli. It protects the cell against host defenses or physical environmental stresses, such as desiccation. The component capsular polysaccharides (CPSs) are major surface antigens in E. coli. They are named K antigens (after the German word Kapsel). Due to variations in CPS structures, more than 80 serologically unique K antigens exist in E. coli. Despite the hypervariability in CPS structures, only two capsule-assembly strategies exist in E. coli. These have led to the assignment of group 1 and group 2 capsules, and many of the key elements of the corresponding assembly pathways have been resolved. Structural features, as well as genetic and regulatory variations, give rise to additional groups 3 and 4. These employ the same biosynthesis processes described in groups 2 and 1, respectively. Each isolate possesses a distinctive set of cytosolic and inner-membrane enzymes, which generate a precise CPS structure, defining a given K serotype. Once synthesized, a multiprotein complex is needed to translocate the nascent CPS across the Gram-negative cell envelope to the outer surface of the outer membrane, where the capsule structure is assembled. While the translocation machineries for group 1 and group 2 CPSs are fundamentally different from one another, they possess no specificity for a given CPS structure. Each is conserved in all isolates producing capsules belonging to a particular group.
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26
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Bhardwaj A, Walker-Kopp N, Casjens SR, Cingolani G. An evolutionarily conserved family of virion tail needles related to bacteriophage P22 gp26: correlation between structural stability and length of the alpha-helical trimeric coiled coil. J Mol Biol 2009; 391:227-45. [PMID: 19482036 DOI: 10.1016/j.jmb.2009.05.069] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2009] [Revised: 05/21/2009] [Accepted: 05/26/2009] [Indexed: 12/01/2022]
Abstract
Bacteriophages of the Podoviridae family use short noncontractile tails to inject their genetic material into Gram-negative bacteria. In phage P22, the tail contains a thin needle, encoded by the phage gene 26, which is essential both for stabilization and for ejection of the packaged viral genome. Bioinformatic analysis of the N-terminal domain of gp26 (residues 1-60) led us to identify a family of genes encoding putative homologues of the tail needle gp26. To validate this idea experimentally and to explore their diversity, we cloned the gp26-like gene from phages HK620, Sf6 and HS1, and characterized these gene products in solution. All gp26-like factors contain an elongated alpha-helical coiled-coil core consisting of repeating, adjacent trimerization heptads and form trimeric fibers with length ranging between about 240 to 300 A. gp26 tail needles display a high level of structural stability in solution, with T(m) (temperature of melting) between 85 and 95 degrees C. To determine how the structural stability of these phage fibers correlates with the length of the alpha-helical core, we investigated the effect of insertions and deletions in the helical core. In the P22 tail needle, we identified an 85-residue-long helical domain, termed MiCRU (minimal coiled-coil repeat unit), that can be inserted in-frame inside the gp26 helical core, preserving the straight morphology of the fiber. Likewise, we were able to remove three quarters of the helical core of the HS1 tail needle, minimally decreasing the stability of the fiber. We conclude that in the gp26 family of tail needles, structural stability increases nonlinearly with the length of the alpha-helical core. Thus, the overall stability of these bacteriophage fibers is not solely dependent on the number of trimerization repeats in the alpha-helical core.
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Affiliation(s)
- Anshul Bhardwaj
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, 750 E. Adams Street, Syracuse, NY 13210, USA
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27
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An engineered R-type pyocin is a highly specific and sensitive bactericidal agent for the food-borne pathogen Escherichia coli O157:H7. Antimicrob Agents Chemother 2009; 53:3074-80. [PMID: 19349519 DOI: 10.1128/aac.01660-08] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Some strains of Pseudomonas aeruginosa produce R-type pyocins, which are high-molecular-weight phage tail-like protein complexes that have bactericidal activity against other Pseudomonas strains. These particles recognize and bind to bacterial surface structures via tail fibers, their primary spectrum determinant. R-type pyocins kill the cell by contracting a sheath-like structure and inserting their hollow core through the cell envelope, resulting in dissipation of the cellular membrane potential. We have retargeted an R-type pyocin to Escherichia coli O157:H7 by fusing a tail spike protein from an O157-specific phage, phiV10, to the pyocin tail fiber. The phiV10 tail spike protein recognizes and degrades the O157 lipopolysaccharide. This engineered pyocin, termed AVR2-V10, is sensitive and specific, killing 100% of diverse E. coli O157:H7 isolates but no other serotypes tested. AVR2-V10 can kill E. coli O157:H7 on beef surfaces, making it a candidate agent for the elimination of this pathogen from food products. All rare AVR2-V10-resistant mutants isolated and examined have lost the ability to produce the O157 antigen and are expected to have compromised virulence. In addition, E. coli O157:H7 exposed to and killed by AVR2-V10 do not release Shiga toxin, as is often the case with many antibiotics, suggesting potential therapeutic applications. The demonstration that a novel R-type pyocin can be created in the laboratory by fusing a catalytic tail spike from the family Podoviridae to a tail fiber of a member of the family Myoviridae is evidence that the plasticity observed among bacteriophage tail genes can, with modern molecular techniques, be exploited to produce nonnatural, targeted antimicrobial agents.
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Villafane R, Zayas M, Gilcrease EB, Kropinski AM, Casjens SR. Genomic analysis of bacteriophage epsilon 34 of Salmonella enterica serovar Anatum (15+). BMC Microbiol 2008; 8:227. [PMID: 19091116 PMCID: PMC2629481 DOI: 10.1186/1471-2180-8-227] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2008] [Accepted: 12/17/2008] [Indexed: 12/21/2022] Open
Abstract
Background The presence of prophages has been an important variable in genetic exchange and divergence in most bacteria. This study reports the determination of the genomic sequence of Salmonella phage ε34, a temperate bacteriophage that was important in the early study of prophages that modify their hosts' cell surface and is of a type (P22-like) that is common in Salmonella genomes. Results The sequence shows that ε34 is a mosaically related member of the P22 branch of the lambdoid phages. Its sequence is compared with the known P22-like phages and several related but previously unanalyzed prophage sequences in reported bacterial genome sequences. Conclusion These comparisons indicate that there has been little if any genetic exchange within the procapsid assembly gene cluster with P22-like E. coli/Shigella phages that are have orthologous but divergent genes in this region. Presumably this observation reflects the fact that virion assembly proteins interact intimately and divergent proteins can no longer interact. On the other hand, non-assembly genes in the "ant moron" appear to be in a state of rapid flux, and regulatory genes outside the assembly gene cluster have clearly enjoyed numerous and recent horizontal exchanges with phages outside the P22-like group. The present analysis also shows that ε34 harbors a gtrABC gene cluster which should encode the enzymatic machinery to chemically modify the host O antigen polysaccharide, thus explaining its ability to alter its host's serotype. A comprehensive comparative analysis of the known phage gtrABC gene clusters shows that they are highly mobile, having been exchanged even between phage types, and that most "bacterial" gtrABC genes lie in prophages that vary from being largely intact to highly degraded. Clearly, temperate phages are very major contributors to the O-antigen serotype of their Salmonella hosts.
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Affiliation(s)
- Robert Villafane
- Ponce School of Medicine, Department of Microbiology, Ponce, Puerto Rico 00732, USA
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Cytolethal distending toxin type I and type IV genes are framed with lambdoid prophage genes in extraintestinal pathogenic Escherichia coli. Infect Immun 2008; 77:492-500. [PMID: 18981247 DOI: 10.1128/iai.00962-08] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Five types of cytolethal distending toxin (CDT-I to CDT-V) have been identified in Escherichia coli. In the present study we cloned and sequenced the cdt-IV operon and flanking region from a porcine extraintestinal pathogenic E. coli (ExPEC) strain belonging to serogroup O75. We confirmed that similar to other CDTs, CDT-IV induced phosphorylation of host histone H2AX, a sensitive marker of DNA double-strand breaks, and blocked the HeLa cell cycle at the G(2)-M transition. The cdt-IV genes were framed by lambdoid prophage genes. We cloned and sequenced the cdt-I operon and flanking regions from a human ExPEC O18:K1:H7 strain and observed that cdt-I genes were also flanked by lambdoid prophage genes. PCR studies indicated that a gene coding for a putative protease was always associated with the cdtC-IV gene but was not associated with cdtC genes in strains producing CDT-I, CDT-III, and CDT-V. Our results suggest that the cdt-I and cdt-IV genes might have been acquired from a common ancestor by phage transduction and evolved in their bacterial hosts. The lysogenic bacteriophages have the potential to carry nonessential "cargo" genes or "morons" and therefore play a crucial role in the generation of genetic diversity within ExPEC.
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