Related Experiment Video

Updated: May 10, 2026

T4 Bacteriophage and E. coli Interaction in the Murine Intestine: A Prototypical Model for Studying Host-Bacteriophage Dynamics In Vivo
08:46

T4 Bacteriophage and E. coli Interaction in the Murine Intestine: A Prototypical Model for Studying Host-Bacteriophage Dynamics In Vivo

Published on: January 26, 2024

Short-term antagonism between bacteriophages and macrophages decreases with bacteria-phage coevolution

Meaghan Castledine1, Zuzanna Szczutkowska1, Andrew Matthews1

  • 1Department of Ecology & Conservation, Environment and Sustainability Institute, University of Exeter, Penryn, Cornwall, TR10 9EZ, United Kingdom.

The ISME Journal
|May 8, 2026
PubMed

Insights

Phage therapy success varies. Macrophages initially antagonize bacteriophages, but this effect disappears as bacteria evolve resistance, impacting overall treatment outcomes.

Area of Science:

  • Microbiology
  • Immunology
  • Evolutionary Biology

Background:

  • Antimicrobial resistance necessitates novel therapeutic strategies like phage therapy.
  • Phage therapy involves using bacteriophages (viruses that infect bacteria) to combat bacterial infections.
  • Immune system components, such as macrophages, can influence phage therapy efficacy, with variable short-term effects.

Purpose of the Study:

  • To investigate the in vitro interactions between macrophages, bacteriophages, and the pathogen Pseudomonas aeruginosa.
  • To assess the impact of these interactions on bacterial resistance evolution and population dynamics over time.
  • To understand how short-term immune responses affect long-term phage therapy outcomes.

Main Methods:

  • Culturing Pseudomonas aeruginosa in the presence of bacteriophages and macrophages.
  • Monitoring bacterial and phage population densities over extended periods.
  • Quantifying the evolution of bacteriophage resistance in bacterial populations.

Main Results:

  • Macrophages exhibited short-term antagonism towards bacteriophages, consistent with prior research.
  • This antagonism diminished as bacterial populations recovered due to the rapid evolution of bacteriophage resistance.
  • Macrophages increased net bacterial resistance levels and limited bacteriophage infectivity gains, without altering overall population dynamics.

Conclusions:

  • Immune cell interactions with bacteriophages are dynamic and change over time, particularly with the evolution of bacterial resistance.
  • Short-term observations of immune-phage interactions may not accurately predict long-term phage therapy success.
  • Characterizing immune system effects on phage therapy across both short and long timescales is crucial for optimizing treatment strategies.
Keywords:
Pseudomonas aeruginosabacteriophagesexperimental evolutionimmune systemmacrophagesphage therapy

More Related Videos

Bacteriophage Removal from Infected Salmonella Cultures07:19

Bacteriophage Removal from Infected Salmonella Cultures

Published on: June 28, 2024

Understanding the Impact of Temperate Bacteriophages on Their Lysogens Through Transcriptomics09:23

Understanding the Impact of Temperate Bacteriophages on Their Lysogens Through Transcriptomics

Published on: January 5, 2024

Related Concept Videos

Lytic Cycle of Bacteriophages01:30

Lytic Cycle of Bacteriophages

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 lytic replication...
Defense Against Bacterial Pathogens01:31

Defense Against Bacterial Pathogens

The human immune system is a complex network of cells, tissues, and organs that work together to defend the body against bacterial infections. It consists of various immune cells, each playing a specific role in the defense mechanism.
Phagocytes
Phagocytes are the frontline soldiers of the immune system. They include neutrophils and macrophages. Neutrophils are the most abundant type of white blood cell and are quickly mobilized to the site of infection. Macrophages are larger cells that patrol...
Regulation of Bacterial Virulence01:28

Regulation of Bacterial Virulence

Pathogenic bacteria employ a range of regulatory mechanisms to modulate the expression of virulence genes in response to environmental and host-derived signals. These mechanisms ensure that virulence factors are expressed only under favorable conditions, thereby optimizing infection and survival strategies.Mechanisms of Virulence RegulationKey regulatory strategies include:Two-Component Systems: These consist of a membrane-bound sensor kinase and a cytoplasmic response regulator. Environmental...
Microbial Interactions: Parasitism01:22

Microbial Interactions: Parasitism

Parasitism is a form of microbial interaction in which parasitic microbes exploit a host organism for nutrients and shelter, often at the host's expense. Unlike mutualistic relationships, where both organisms benefit, parasitism benefits only the parasite and harms the host.Classification of ParasitesMicrobial parasites are broadly classified based on their location relative to the host.Ectoparasites remain on the host’s surface, such as the skin or outer tissues, drawing nutrients...
Viral Replication: Lysogenic Cycle01:16

Viral Replication: Lysogenic Cycle

The lysogenic cycle is a crucial viral replication strategy that allows bacteriophages to persist within host cells without immediately destroying them. This process is primarily observed in temperate phages, such as bacteriophage lambda (λ), which infects Escherichia coli. The cycle allows the viral genome to persist across bacterial generations while keeping host cells viable.Integration of the Viral GenomeUpon infection, bacteriophage lambda attaches to the bacterial surface and injects its...
Lysogenic Cycle of Bacteriophages00:43

Lysogenic Cycle of Bacteriophages

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...