scholarly journals Viral satellites exploit phage proteins to escape degradation of the bacterial host chromosome

2019 ◽  
Author(s):  
Amelia C. McKitterick ◽  
Stephanie G. Hays ◽  
Munirul Alam ◽  
Kimberley D. Seed
Keyword(s):  
Vibrio Cholerae ◽  
Bacterial Genome ◽  
Lytic Phage ◽  
Bacterial Host ◽  
Host Chromosome ◽  
Defense Systems ◽  
Phage Production ◽  
Phage Proteins ◽  
Insight Into ◽  
Phage Activity

SummaryPhage defense systems are often found on mobile genetic elements (MGEs), where they constitutively defend against invaders or are induced to respond to new assaults. Some MGEs, the phage satellites, exploit phages for their own transmission after induction, reducing phage production and protecting their hosts in the process. One such satellite inVibrio cholerae, PLE, is triggered by the lytic phage ICP1 to excise from the chromosome, replicate, and transduce to neighboring cells, completely sabotaging phage production. Here, we found that ICP1 has evolved to possess one of two syntenic loci encoding an SF1B-type helicase, either of which PLE can exploit to directly drive PLE replication. Further, loss of PLE mobilization limits anti-phage activity due to phage-mediated degradation of the bacterial genome. Our work provides insight into the unique challenges imposed on the parasites of lytic phages and underscores the adaptions of these satellites to their ever-evolving target phage.

scholarly journals Survival Strategies of Streptococcus pyogenes in Response to Phage Infection

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 612
Author(s):  
Dior Beerens ◽  
Sandra Franch-Arroyo ◽  
Timothy J. Sullivan ◽  
Christian Goosmann ◽  
Volker Brinkmann ◽  
...  
Keyword(s):  
Streptococcus Pyogenes ◽  
Membrane Vesicles ◽  
Phage Infection ◽  
Survival Strategies ◽  
Modular Organization ◽  
Lytic Phage ◽  
Bacterial Host ◽  
Host Chromosome ◽  
Double Stranded Dna ◽  
Insight Into

Bacteriophages exert strong evolutionary pressure on their microbial hosts. In their lytic lifecycle, complete bacterial subpopulations are utilized as hosts for bacteriophage replication. However, during their lysogenic lifecycle, bacteriophages can integrate into the host chromosome and alter the host’s genomic make-up, possibly resulting in evolutionary important adjustments. Not surprisingly, bacteria have evolved sophisticated immune systems to protect against phage infection. Streptococcus pyogenes isolates are frequently lysogenic and their prophages have been shown to be major contributors to the virulence of this pathogen. Most S. pyogenes phage research has focused on genomic prophages in relation to virulence, but little is known about the defensive arsenal of S. pyogenes against lytic phage infection. Here, we characterized Phage A1, an S. pyogenes bacteriophage, and investigated several mechanisms that S. pyogenes utilizes to protect itself against phage predation. We show that Phage A1 belongs to the Siphoviridae family and contains a circular double-stranded DNA genome that follows a modular organization described for other streptococcal phages. After infection, the Phage A1 genome can be detected in isolated S. pyogenes survivor strains, which enables the survival of the bacterial host and Phage A1 resistance. Furthermore, we demonstrate that the type II-A CRISPR-Cas system of S. pyogenes acquires new spacers upon phage infection, which are increasingly detectable in the absence of a capsule. Lastly, we show that S. pyogenes produces membrane vesicles that bind to phages, thereby limiting the pool of phages available for infection. Altogether, this work provides novel insight into survival strategies employed by S. pyogenes to combat phage predation.

scholarly journals Viral Satellites Exploit Phage Proteins to Escape Degradation of the Bacterial Host Chromosome

2019 ◽  
Vol 26 (4) ◽  
pp. 504-514.e4 ◽  
Author(s):  
Amelia C. McKitterick ◽  
Stephanie G. Hays ◽  
Fatema-Tuz Johura ◽  
Munirul Alam ◽  
Kimberley D. Seed
Keyword(s):  
Bacterial Host ◽  
Host Chromosome ◽  
Phage Proteins

scholarly journals CryoEM structure of the type IVa pilus secretin required for natural competence in Vibrio cholerae

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Sara J. Weaver ◽  
Davi R. Ortega ◽  
Matthew H. Sazinsky ◽  
Triana N. Dalia ◽  
Ankur B. Dalia ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Vibrio Cholerae ◽  
Natural Transformation ◽  
Domain Architecture ◽  
Genetic Material ◽  
Surface Binding ◽  
Exogenous Dna ◽  
Insight Into

Abstract Natural transformation is the process by which bacteria take up genetic material from their environment and integrate it into their genome by homologous recombination. It represents one mode of horizontal gene transfer and contributes to the spread of traits like antibiotic resistance. In Vibrio cholerae, a type IVa pilus (T4aP) is thought to facilitate natural transformation by extending from the cell surface, binding to exogenous DNA, and retracting to thread this DNA through the outer membrane secretin, PilQ. Here, we use a functional tagged allele of VcPilQ purified from native V. cholerae cells to determine the cryoEM structure of the VcPilQ secretin in amphipol to ~2.7 Å. We use bioinformatics to examine the domain architecture and gene neighborhood of T4aP secretins in Proteobacteria in comparison with VcPilQ. This structure highlights differences in the architecture of the T4aP secretin from the type II and type III secretion system secretins. Based on our cryoEM structure, we design a series of mutants to reversibly regulate VcPilQ gate dynamics. These experiments support the idea of VcPilQ as a potential druggable target and provide insight into the channel that DNA likely traverses to promote the spread of antibiotic resistance via horizontal gene transfer by natural transformation.

scholarly journals Genome replication dynamics of a bacteriophage and its satellite reveal strategies for parasitism and viral restriction

2019 ◽  
Author(s):  
Zachary K Barth ◽  
Tania V Silvas ◽  
Angus Angermeyer ◽  
Kimberley D Seed
Keyword(s):  
Dna Replication ◽  
Vibrio Cholerae ◽  
Host Cells ◽  
Initiation Factor ◽  
Cell Populations ◽  
Lytic Phage ◽  
Genome Replication ◽  
Origin Of Replication ◽  
New Host ◽  
Viral Restriction

Abstract Phage-inducible chromosomal island-like elements (PLEs) are bacteriophage satellites found in Vibrio cholerae. PLEs parasitize the lytic phage ICP1, excising from the bacterial chromosome, replicating, and mobilizing to new host cells following cell lysis. PLEs protect their host cell populations by completely restricting the production of ICP1 progeny. Previously, it was found that ICP1 replication was reduced during PLE(+) infection. Despite robust replication of the PLE genome, relatively few transducing units are produced. We investigated if PLE DNA replication itself is antagonistic to ICP1 replication. Here we identify key constituents of PLE replication and assess their role in interference of ICP1. PLE encodes a RepA_N initiation factor that is sufficient to drive replication from the PLE origin of replication during ICP1 infection. In contrast to previously characterized bacteriophage satellites, expression of the PLE initiation factor was not sufficient for PLE replication in the absence of phage. Replication of PLE was necessary for interference of ICP1 DNA replication, but replication of a minimalized PLE replicon was not sufficient for ICP1 DNA replication interference. Despite restoration of ICP1 DNA replication, non-replicating PLE remained broadly inhibitory against ICP1. These results suggest that PLE DNA replication is one of multiple mechanisms contributing to ICP1 restriction.

scholarly journals Transmission of Vibrio cholerae Is Antagonized by Lytic Phage and Entry into the Aquatic Environment

2008 ◽  
Vol 4 (10) ◽  
pp. e1000187 ◽  
Author(s):  
Eric J. Nelson ◽  
Ashrafuzzaman Chowdhury ◽  
James Flynn ◽  
Stefan Schild ◽  
Lori Bourassa ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Aquatic Environment ◽  
Lytic Phage

FURTHER INSIGHT INTO PRODUCTION AND DIARRHEAGENICITY OF ZONULA OCCLUDENS TOXIN (ZOT) BY VIBRIO CHOLERAE

1991 ◽  
Vol 13 (3) ◽  
pp. 327
Author(s):  
A. Fasano ◽  
B. Baudry ◽  
J. B. Kaper ◽  
C. Ciarla ◽  
L. Ferraro ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Zonula Occludens ◽  
Zonula Occludens Toxin ◽  
Insight Into

scholarly journals MM1, a Temperate Bacteriophage of the Type 23F Spanish/USA Multiresistant Epidemic Clone of Streptococcus pneumoniae: Structural Analysis of the Site-Specific Integration System

2000 ◽  
Vol 74 (17) ◽  
pp. 7803-7813 ◽  
Author(s):  
Emmanuel Gindreau ◽  
Rubens López ◽  
Pedro García
Keyword(s):  
Streptococcus Pneumoniae ◽  
Bacterial Genome ◽  
Nucleotide Sequencing ◽  
Sequence Information ◽  
Host Chromosome ◽  
Integrase Gene ◽  
Site Specific Integration ◽  
Attachment Sites ◽  
Pneumococcal Strain ◽  
Foreign Genes

ABSTRACT We have characterized a temperate phage (MM1) from a clinical isolate of the multiply antibiotic-resistant Spanish/American 23FStreptococcus pneumoniae clone (Spain23F-1 strain). The 40-kb double-stranded genome of MM1 has been isolated as a DNA-protein complex. The use of MM1 DNA as a probe revealed that the phage genome is integrated in the host chromosome. The host and phage attachment sites, attB and attP, respectively, have been determined. Nucleotide sequencing of the attachment sites identified a 15-bp core site (5′-TTATAATTCATCCGC-3′) that has not been found in any bacterial genome described so far. Sequence information revealed the presence of an integrase gene (int), which represents the first identification of an integrase in the pneumococcal system. A 1.5-kb DNA fragment embracingattP and the int gene contained all of the genetic information needed for stable integration of a nonreplicative plasmid into the attB site of a pneumococcal strain. This vector will facilitate the introduction of foreign genes into the pneumococcal chromosome. Interestingly, DNAs highly similar to that of MM1 have been detected in several clinical pneumococcal isolates of different capsular types, suggesting a widespread distribution of these phages in relevant pathogenic strains.

scholarly journals Molecular Characterization of ISCR1-MediatedblaPER-1in a Non-O1, Non-O139 Vibrio cholerae Strain from China

2015 ◽  
Vol 59 (7) ◽  
pp. 4293-4295 ◽  
Author(s):  
Jun Wu ◽  
Lianyan Xie ◽  
Fangfang Zhang ◽  
Yuxing Ni ◽  
Jingyong Sun
Keyword(s):  
Vibrio Cholerae ◽  
Molecular Characterization ◽  
Cholerae Strain ◽  
Class 1 Integron ◽  
Content Type ◽  
Conserved Sequence ◽  
Circular Molecule ◽  
Class 1 ◽  
Insight Into

ABSTRACTWe report the detection of PER-1 extended-spectrum β-lactamase (ESBL) in a clinical non-O1, non-O139Vibrio choleraestrain from China. ISCR1-mediatedblaPER-1was embedded in a complex In4family class 1 integron belonging to the lineage of Tn1696on a conjugative IncA/C plasmid. A free 8.98-kb circular molecule present with the ISCR1-blaPER-1–truncated 3′-conserved sequence (CS) structure was detected in this isolate. These findings may provide insight into the mobilization ofblaPER-1.

scholarly journals Burkholderia cepacia Complex Phage-Antibiotic Synergy (PAS): Antibiotics Stimulate Lytic Phage Activity

2014 ◽  
Vol 81 (3) ◽  
pp. 1132-1138 ◽  
Author(s):  
Fatima Kamal ◽  
Jonathan J. Dennis
Keyword(s):  
Burkholderia Cepacia ◽  
Galleria Mellonella ◽  
Burkholderia Cenocepacia ◽  
Burkholderia Cepacia Complex ◽  
Lytic Phage ◽  
Bacterial Killing ◽  
Content Type ◽  
Drug Classes ◽  
Phage Production ◽  
A Chain

ABSTRACTTheBurkholderia cepaciacomplex (Bcc) is a group of at least 18 species of Gram-negative opportunistic pathogens that can cause chronic lung infection in cystic fibrosis (CF) patients. Bcc organisms possess high levels of innate antimicrobial resistance, and alternative therapeutic strategies are urgently needed. One proposed alternative treatment is phage therapy, the therapeutic application of bacterial viruses (or bacteriophages). Recently, some phages have been observed to form larger plaques in the presence of sublethal concentrations of certain antibiotics; this effect has been termed phage-antibiotic synergy (PAS). Those reports suggest that some antibiotics stimulate increased production of phages under certain conditions. The aim of this study is to examine PAS in phages that infectBurkholderia cenocepaciastrains C6433 and K56-2. Bcc phages KS12 and KS14 were tested for PAS, using 6 antibiotics representing 4 different drug classes. Of the antibiotics tested, the most pronounced effects were observed for meropenem, ciprofloxacin, and tetracycline. When grown with subinhibitory concentrations of these three antibiotics, cells developed a chain-like arrangement, an elongated morphology, and a clustered arrangement, respectively. When treated with progressively higher antibiotic concentrations, both the sizes of plaques and phage titers increased, up to a maximum.B. cenocepaciaK56-2-infectedGalleria mellonellalarvae treated with phage KS12 and low-dose meropenem demonstrated increased survival over controls treated with KS12 or antibiotic alone. These results suggest that antibiotics can be combined with phages to stimulate increased phage production and/or activity and thus improve the efficacy of bacterial killing.

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