Related Experiment Video
Updated: Dec 15, 2025
09:40
Phage Phenomics: Physiological Approaches to Characterize Novel Viral Proteins
Published on: June 11, 2015
12.6K
Bacteroides thetaiotaomicron-Infecting Bacteriophage Isolates Inform Sequence-Based Host Range Predictions
Andrew J Hryckowian1, Bryan D Merrill1, Nathan T Porter2
1Department of Microbiology & Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA.
Cell Host & Microbe
|July 12, 2020
Summary
Scientists explored bacteriophages (phages), viruses that infect bacteria, in the human gut microbiome. They sequenced 27 new phages infecting Bacteroides thetaiotaomicron, revealing novel viral diversity and genes linked to infectivity.
Area of Science:
- Microbiology
- Virology
- Genomics
- Gut Microbiome Research
Background:
- The human gut microbiome is dominated by bacterial research, with limited understanding of bacteriophages (phages).
- Phages are abundant in the gut, yet few have been isolated and characterized.
- Understanding gut phages is crucial for a complete picture of gut microbial ecology.
Purpose of the Study:
- To isolate and sequence novel phages from the human gut microbiome.
- To characterize phages infecting the prevalent gut bacterium Bacteroides thetaiotaomicron.
- To explore the diversity of gut phages and identify genes associated with infectivity.
Main Methods:
- Isolation and whole-genome sequencing of 27 phages from human gut samples.
- Bioinformatic analysis comparing new phage genomes to existing databases and metagenomic data.
- Analysis of phage host tropisms to identify structure-infectivity gene relationships.
Main Results:
- 27 novel phage genomes infecting Bacteroides thetaiotaomicron were sequenced.
- Most isolates were distinct from known phages, with two identified as crAss-like phages.
- Comparison with metagenomes revealed similarities to inferred phages and significant unexplored viral diversity.
- Specific phage structural gene alleles associated with infectivity were identified.
Conclusions:
- This study significantly expands the known diversity of human gut phages, illuminating the 'viral dark matter'.
- The findings provide a foundation for integrating isolation and sequencing approaches to study gut viruses.
- Identified gene-infectivity links offer insights into phage-host interactions within the gut ecosystem.
Related Concept Videos
01:26DNA Bacteriophages
578
Bacteriophages, or phages, are viruses that specifically infect bacteria, utilizing their genetic material to hijack host cellular machinery for replication. DNA bacteriophages employ single-stranded DNA (ssDNA) or double-stranded DNA (dsDNA) genomes. These phages exhibit diverse replication strategies and host interactions, influencing their ecological roles and applications in biotechnology and medicine.ssDNA BacteriophagesssDNA phages, with their small genomes, utilize unique strategies to...
578
01:30Lytic Cycle of Bacteriophages
76.9K
Bacteriophages, also known as phages, are specialized viruses that infect bacteria. A key characteristic of phages is their distinctive “head-tail” morphology. A phage begins the infection process (i.e., lytic cycle) by attaching to the outside of a bacterial cell. Attachment is accomplished via proteins in the phage tail that bind to specific receptor proteins on the outer surface of the bacterium. The tail injects the phage’s DNA genome into the bacterial cytoplasm. In the...
76.9K
01:29Viruses of Archaea
354
Archaeal viruses play a crucial role in the ecosystems of extremophilic archaea, particularly those belonging to the phyla Euryarchaeota and Crenarchaeota. By shaping host evolution and facilitating gene transfer, these viruses influence microbial communities and contribute to genetic diversity in extreme environments. The archaea they infect thrive in acidic hot springs and hydrothermal vents characterized by high temperatures and low pH. Archaeal viruses exhibit remarkable structural...
354
01:26Bacterial Phylum Bacteroidota
424
The phylum Bacteroidota includes over 700 species classified into four primary orders: Bacteroidales, Cytophagales, Flavobacteriales, and Sphingobacteriales. These gram-negative, non-sporulating rods exhibit saccharolytic capabilities and can be aerobic or fermentative, encompassing obligate aerobes, facultative aerobes, and obligate anaerobes. Many species display gliding motility, though some are nonmotile or use flagella. The genus Bacteroides is well-studied due to its significant role in...
424
01:20Viral Replication: Lytic Cycle
954
Bacteriophages, or phages, are viruses that specifically infect bacteria. Among them, T-even bacteriophages, such as T4, exhibit a well-characterized lytic replication cycle in Escherichia coli (E. coli). This process ensures the rapid proliferation of the virus while ultimately leading to the destruction of the bacterial host.Attachment and DNA InjectionThe infection process begins with the recognition and binding of the T4 phage to the E. coli cell surface. Tail fibers of the phage...
954
00:43Lysogenic Cycle of Bacteriophages
67.1K
In contrast to the lytic cycle, phages infecting bacteria via the lysogenic cycle do not immediately kill their host cell. Instead, they combine their genome with the host genome, allowing the bacteria to replicate the phage DNA along with the bacterial genome. The incorporated copy of the phage genome is called the prophage. Some prophages can re-activate and enter the lytic cycle. This often occurs in response to a perturbation, such as DNA damage, but can also transpire in the absence of...
67.1K