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Lysogenic bacteriophage

Gabrielle M Gentile, Katherine S Wetzel, Rebekah M Dedrick, Matthew T Montgomery, Rebecca A Garlena, Deborah Jacobs-Sera, Graham F Hatfull
The arms race between bacteria and their bacteriophages profoundly influences microbial evolution. With an estimated 1023 phage infections occurring per second, there is strong selection for both bacterial survival and phage coevolution for continued propagation. Many phage resistance systems, including restriction-modification systems, clustered regularly interspaced short palindromic repeat-Cas (CRISPR-Cas) systems, a variety of abortive infection systems, and many others that are not yet mechanistically defined, have been described...
March 19, 2019: MBio
Paul Hyman
For a bacteriophage to be useful for phage therapy it must be both isolated from the environment and shown to have certain characteristics beyond just killing strains of the target bacterial pathogen. These include desirable characteristics such as a relatively broad host range and a lack of other characteristics such as carrying toxin genes and the ability to form a lysogen. While phages are commonly isolated first and subsequently characterized, it is possible to alter isolation procedures to bias the isolation toward phages with desirable characteristics...
March 11, 2019: Pharmaceuticals
Jorge A Moura de Sousa, Eduardo P C Rocha
Microbial communities are shaped by bacteriophages through predation and lysogeny. A better understanding of the interactions between these processes across different types of environments is key to elucidate how phages mediate microbial competition and to design efficient phage therapies. We introduce an individual-based model (eVIVALDI) to investigate the role of environmental structure in the elimination of a population with a combined treatment of antibiotics and virulent phages, and in the invasion of a population of phage-sensitive bacteria by lysogens...
February 28, 2019: Scientific Reports
Bhaskar Chandra Mohan Ramisetty, Pavithra Anantharaman Sudhakari
Bacterial genomes are highly plastic allowing the generation of variants through mutations and acquisition of genetic information. The fittest variants are then selected by the econiche thereby allowing the bacterial adaptation and colonization of the habitat. Larger genomes, however, may impose metabolic burden and hence bacterial genomes are optimized by the loss of frivolous genetic information. The activity of temperate bacteriophages has acute consequences on the bacterial population as well as the bacterial genome through lytic and lysogenic cycles...
2019: Frontiers in Genetics
Eugen Pfeifer, Max Hünnefeld, Ovidiu Popa, Julia Frunzke
Phages, viruses that prey on bacteria, are the most abundant and diverse inhabitants of the Earth. Temperate bacteriophages can integrate into the host genome and, as so-called prophages, maintain a long-term association with their host. The close relationship between host and virus has significantly shaped microbial evolution and phage elements may benefit their host by providing new functions. Nevertheless, the strong activity of phage promoters and potentially toxic gene products may impose a severe fitness burden and must be tightly controlled...
February 20, 2019: Journal of Molecular Biology
Jee-Hwan Oh, Laura M Alexander, Meichen Pan, Kathryn L Schueler, Mark P Keller, Alan D Attie, Jens Walter, Jan-Peter van Pijkeren
The mammalian intestinal tract contains a complex microbial ecosystem with many lysogens, which are bacteria containing dormant phages (prophages) inserted within their genomes. Approximately half of intestinal viruses are derived from lysogens, suggesting that these bacteria encounter triggers that promote phage production. We show that prophages of the gut symbiont Lactobacillus reuteri are activated during gastrointestinal transit and that phage production is further increased in response to a fructose-enriched diet...
December 24, 2018: Cell Host & Microbe
N K El-Dougdoug, S Cucic, A G Abdelhamid, L Brovko, A M Kropinski, M W Griffiths, H Anany
Bacteriophages have been envisioned as tools to control a variety of foodborne pathogenic bacteria. Salmonella is a foodborne pathogen that is a threat to public health around the world. Contaminated tomatoes have been associated with several Salmonella outbreaks. Hence, the objective of this work was to identify and characterize different lytic bacteriophages against Salmonella Newport, as one of top ten Salmonella serovars associated with human salmonellosis in North America, and then apply these phages to enhance the safety of cherry tomatoes...
January 6, 2019: International Journal of Food Microbiology
Joanna Kazimierczak, Ewelina Agnieszka Wójcik, Jolanta Witaszewska, Arkadiusz Guziński, Elżbieta Górecka, Małgorzata Stańczyk, Edyta Kaczorek, Andrzej Krzysztof Siwicki, Jarosław Dastych
BACKGROUND: Aquaculture is the fastest growing sector of food production worldwide. However, one of the major reasons limiting its effectiveness are infectious diseases among aquatic organisms resulting in vast economic losses. Fighting such infections with chemotherapy is normally used as a rapid and effective treatment. The rise of antibiotic resistance, however, is limiting the efficacy of antibiotics and creates environmental and human safety concerns due to their massive application in the aquatic environment...
January 8, 2019: Virology Journal
Loris Riccardo Lopetuso, Maria Ernestina Giorgio, Angela Saviano, Franco Scaldaferri, Antonio Gasbarrini, Giovanni Cammarota
Bacteriocins are bactericidal peptides, ribosomally synthesized, with an inhibitory activity against diverse groups of undesirable microorganisms. Bacteriocins are produced by both gram-positive and gram-negative bacteria, and to a lesser extent by some archaea. Bacteriophages are viruses that are able to infect bacterial cells and force them to produce viral components, using a lytic or lysogenic cycle. They constitute a large community in the human gut called the phageome, the most abundant part of the gut virome...
January 6, 2019: International Journal of Molecular Sciences
Vinícius da Silva Duarte, Sabrina Giaretta, Stefano Campanaro, Laura Treu, Andrea Armani, Armin Tarrah, Sérgio Oliveira de Paula, Alessio Giacomini, Viviana Corich
Streptococcus thermophilus is considered one of the most important species for the dairy industry. Due to their diffusion in dairy environments, bacteriophages can represent a threat to this widely used bacterial species. Despite the presence of a CRISPR-Cas system in the S. thermophilus genome, some lysogenic strains harbor cryptic prophages that can increase the phage-host resistance defense. This characteristic was identified in the dairy strain S. thermophilus M17PTZA496, which contains two integrated prophages 51...
December 22, 2018: Viruses
Abdoallah Sharaf, Miroslav Oborník, Adel Hammad, Sohair El-Afifi, Eman Marei
Next-Generation Sequencing (NGS) technologies provide unique possibilities for the comprehensive assessment of the environmental diversity of bacteriophages. Several Bacillus bacteriophages have been isolated, but very few Bacillus megaterium bacteriophages have been characterized. In this study, we describe the biological characteristics, whole genome sequences, and annotations for two new isolates of the B. megaterium bacteriophages (BM5 and BM10), which were isolated from Egyptian soil samples. Growth analyses indicated that the phages BM5 and BM10 have a shorter latent period (25 and 30 min, respectively) and a smaller burst size (103 and 117 PFU, respectively), in comparison to what is typical for Bacillus phages...
2018: PeerJ
Yuanchao Zhan, Feng Chen
Viruses are the most abundant biological entities in seawater. They influence microbial population dynamics, genetic heterogeneity, and biogeochemical cycles in marine ecosystems. The isolation and characterization of viruses that infect specific hosts have greatly advanced our knowledge of the biological and ecological interactions between viruses and their hosts. Marine Roseobacter are abundant, ubiquitous and diverse in the ocean and play active roles in global biogeochemical cycling, especially the sulfur cycle...
December 16, 2018: Environmental Microbiology
Yuanchao Zhan, Sijun Huang, Feng Chen
We report the complete genome sequences of five bacteriophages infecting Ruegeria pomeroyi DSS-3, a member of the marine Roseobacter lineage. The genomic sequences of these five bacteriophages are almost identical and are closely related to members of the Chivirus genus. The genes associated with the lysogenic cycle were also found.
September 2018: Microbiology Resource Announcements
Muhsin Jamal, Sayed M A U S Bukhari, Saadia Andleeb, Muhammad Ali, Sana Raza, Muhammad A Nawaz, Tahir Hussain, Sadeeq U Rahman, Syed S A Shah
Bacteriophages (phages/viruses) need host bacteria to replicate and propagate. Primarily, a bacteriophage contains a head/capsid to encapsidate the genetic material. Some phages contain tails. Phages encode endolysins to hydrolyze bacterial cell wall. The two main classes of phages are lytic or virulent and lysogenic or temperate. In comparison with antibiotics, to deal with bacterial infections, phage therapy is thought to be more effective. In 1921, the use of phages against bacterial infections was first demonstrated...
November 28, 2018: Journal of Basic Microbiology
Stefania Arioli, Giovanni Eraclio, Giulia Della Scala, Eros Neri, Stefano Colombo, Andrea Scaloni, Maria Grazia Fortina, Diego Mora
Streptococcus thermophilus DSM 20167T showed autolytic behavior when cultured in lactose- and sucrose-limited conditions. The amount of cell lysis induced was inversely related to the energetic status of the cells, as demonstrated by exposing cells to membrane-uncoupling and glycolysis inhibitors. Genome sequence analysis of strain DSM 20617T revealed the presence of a pac -type temperate bacteriophage, designated Φ20617, whose genomic organization and structure resemble those of temperate streptococcal bacteriophages...
2018: Frontiers in Microbiology
Arshnee Moodley, Witold Kot, Sofia Nälgård, Dziuginta Jakociune, Horst Neve, Lars Hestbjerg Hansen, Luca Guardabassi, Finn K Vogensen
We aimed to isolate and characterize bacteriophages (phages) with preferential activity against methicillin-resistant Staphylococcus pseudintermedius (MRSP), a multidrug-resistant canine pathogen. Four phages were isolated from canine faeces using two MRSP strains as initial hosts. Phage host range was evaluated by the spot test on 17 MRSP, 43 methicillin-susceptible S. pseudintermedius (MSSP), and six other staphylococci isolated from dogs. Transmission electron microscopy was used for presumptive identification followed by whole genome sequencing (WGS)...
November 12, 2018: Research in Veterinary Science
Astrid Wahl, Aurélia Battesti, Mireille Ansaldi
Thanks to the exponentially increasing number of publicly available bacterial genome sequences, one can now estimate the important contribution of integrated viral sequences to the diversity of bacterial genomes. Indeed, temperate bacteriophages are able to stably integrate the genome of their host through site-specific recombination and transmit vertically to the host siblings. Lysogenic conversion has been long acknowledged to provide additional functions to the host, and particularly to bacterial pathogen genomes where prophages contribute important virulence factors...
November 22, 2018: Molecular Microbiology
Sean Benler, Ana Georgina Cobián-Güemes, Katelyn McNair, Shr-Hau Hung, Kyle Levi, Rob Edwards, Forest Rohwer
BACKGROUND: Diversity-generating retroelements (DGRs) are genetic cassettes that selectively mutate target genes to produce hypervariable proteins. First characterized in Bordetella bacteriophage BPP-1, the DGR creates a hypervariable phage tail fiber that enables host tropism switching. Subsequent surveys for DGRs conclude that the majority identified to date are bacterial or archaeal in origin. This work examines bacteriophage and bacterial genomes for novel phage-encoded DGRs. RESULTS: This survey discovered 92 DGRs that were only found in phages exhibiting a temperate lifestyle...
October 23, 2018: Microbiome
Aleksandra Dydecka, Bożena Nejman-Faleńczyk, Sylwia Bloch, Gracja Topka, Agnieszka Necel, Logan W Donaldson, Grzegorz Węgrzyn, Alicja Węgrzyn
The exo-xis region of lambdoid bacteriophage genomes contains several established and potential genes that are evolutionarily conserved, but not essential for phage propagation under laboratory conditions. Nevertheless, deletion or overexpression of either the whole exo-xis region and important regulatory elements can significantly influence the regulation of phage development. This report defines specific roles for orf60a and orf61 in bacteriophage λ and Φ24B , a specific Shiga toxin-converting phage with clinical relevance...
October 11, 2018: Viruses
Jaewoo Bai, Byeonghwa Jeon, Sangryeol Ryu
Salmonella contamination of fresh produce is the primary bacterial cause of a significant number of foodborne outbreaks and infections. Bacteriophages can be used as natural antibacterial agents to control foodborne pathogens. However, the rapid development of bacterial resistance to phage infection is a significant barrier to practical phage application. To overcome this problem, we developed a novel phage cocktail consisting of the three phages (BSPM4, BSP101 and BSP22A) that target different host receptors, including flagella, O-antigen and BtuB, respectively...
February 2019: Food Microbiology
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