Bacterial Immunity
Bacterial Immunity - Related Videos
10:12
Systemic Bacterial Infection and Immune Defense Phenotypes in Drosophila Melanogaster
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Cited by 69 •
2015
Drosophila melanogaster is an outstanding model organism for studying innate immune systems and the physiological consequences of infection and disease. This protocol describes how to deliver robust and quantitatively repeatable bacterial infections to D. melanogaster, and how to subsequently measure infection severity and quantify the host immune response.
08:18
Evaluation of Vaccine-Induced Immunity Against Bacterial Infection in a Mouse Model
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2025
In this video, we describe a protocol to test the efficacy of an acellular pertussis vaccine against Bordetella pertussis infection in mice. Post-vaccination, the mice were subjected to infection, and their tissue homogenate was cultured to analyze the bacterial colonies as a readout of the vaccine-induced protective immunity.
02:34
Intraperitoneal Injection of Bacterial Lipopolysaccharide in Mice to Study Systemic Immune Responses
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2026
Source: Radulovic, K., et al. Injections of Lipopolysaccharide into Mice to Mimic Entrance of Microbial-derived Products After Intestinal Barrier Breach. J. Vis. Exp. (2018)This video demonstrates a step-by-step procedure for injecting lipopolysaccharide (LPS) into mice intraperitoneally to induce systemic inflammation.
12:50
Measuring Bacterial Load and Immune Responses in Mice Infected with Listeria monocytogenes
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Cited by 39 •
2011
Listeria monocytogenes is a model organism for studying immune responses and genetic susceptibility to intracellular bacteria in mice. This method enables one to measure bacterial load and generate single-cell suspensions of the liver and spleen from mice for FACS analysis to determine changes in immune cells due to Listeria infection.
04:00
A Murine Skin Wound Infection Model to Study the Immune Response against a Bacterial Pathogen
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2025
This video demonstrates a technique to generate a murine model of skin wound infection. Upon infecting mice — engineered to express a fluorescent protein in neutrophils — with a genetically modified bioluminescent Staphylococcus aureus — a pathogenic bacteria. The bacterial burden at the infection site and the neutrophil recruitment dynamics can be studied using whole animal imaging.
FAQs
These systems differ mainly in how they detect and respond to invasion. Restriction-modification enzymes act on DNA that the bacterium does not recognize, whereas CRISPR-Cas uses stored fragments from earlier invaders to guide sequence-specific cleavage. Abortive infection takes a different route by limiting pathogen replication through sacrifice of the infected cell, rather than directly describing only DNA cutting.
CRISPR-Cas defense is shaped by molecular memory: fragments of earlier invaders are retained and later used to guide cleavage of matching sequences. This gives the response a sequence-specific basis rather than relying only on general recognition of unfamiliar DNA. In biology research, that feature helps explain how repeated viral exposure can influence bacterial survival and defense behavior.
Abortive infection limits the success of a pathogen by preventing its replication within an infected bacterium, even though the infected cell is sacrificed. The mechanism therefore represents a population-level defense strategy rather than a response focused solely on preserving every individual cell. Its importance lies in restricting pathogen spread under conditions of viral pressure.
Restriction-modification enzymes provide an early barrier to foreign genetic material by cutting DNA that the bacterium does not recognize. Their activity can influence whether incoming genetic information is eliminated or remains available to the cell. Studying this process connects bacterial defense with genetic exchange, because immunity affects which foreign DNA can persist in microbial systems.
A useful comparison considers three questions: what signal identifies the threat, what molecular response follows recognition, and whether the infected cell survives. Restriction-modification systems emphasize recognition and cutting, CRISPR-Cas adds stored sequence information and guided cleavage, and abortive infection limits pathogen replication through cellular sacrifice. This framework distinguishes mechanisms without treating them as interchangeable.
Bacterial immunity has applications in research on antibiotic resistance, microbial ecology, genome engineering, and phage-based therapies. These areas use different aspects of the subject: defense mechanisms help explain microbial interactions and genetic exchange, while sequence-guided cleavage contributes to genome engineering. The same biological principles therefore connect fundamental microbiology with therapeutic and technological development.
The study of bacterial immunity shows how microorganisms respond to persistent viral pressure and how defense systems can shape microbial evolution. Because these mechanisms affect the survival of infected cells and the handling of foreign genetic material, they also influence interactions within microbial communities. This makes bacterial immunity relevant to both cellular biology and broader microbial ecology.