Neutrophil Bacterial Killing
Neutrophil Bacterial Killing - Related Videos
04:29
Assessment of Opsonophagocytic Killing Activity against Bacterial Pathogens
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2025
The video shows an in vitro opsonophagocytic killing assay using a co-culture of human neutrophils with Streptococcus pneumoniae. Antibodies and complement proteins facilitate opsonization of the bacteria, enabling neutrophils to recognize and kill bacteria, showing successful neutrophil opsonophagocytic activity.
03:42
In Vitro Evaluation of Bacterial Killing by Neonatal Mouse Splenic Phagocytes
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2026
Source: Seman, B. G., et.al. Neonatal Imaging Model of Gram-Negative Bacterial Sepsis. J. Vis. Exp. (2020)This video demonstrates the isolation of neutrophils and inflammatory monocytes from neonatal mouse spleens and their application in a luminescent bacterial killing assay. It covers mechanical dissociation, red blood cell lysis, magnetic bead–based cell enrichment, bacterial incubation, and antibiotic protection. Timed luminescence readings indicate initial bacterial internalization...
04:29
Monitoring Neutrophil Recruitment Dynamics and Bacterial Burden at the Infection Site in a Murine Model
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2025
This video demonstrates in vivo imaging to study the neutrophil recruitment dynamics at an infection site in an immunocompromised, transgenic mouse with GFP-expressing neutrophils. It involves injecting luminescent bacteria to cause an infection. This leads to neutrophil recruitment to the infection site, whose tracking is done by imaging.
03:06
An In Vitro Assay to Study the Interaction between Neutrophils and Biofilm
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2025
This video demonstrates an in vitro assay to study neutrophil-biofilm interaction. The pathogenic bacteria embedded in the biofilm and isolated neutrophils were tagged using fluorescent labels, and the immune response by the neutrophils and the evasion of the immune response by the bacteria were assessed using a fluorescence microscope.
08:47
Opsonophagocytic Killing Assay to Assess Immunological Responses Against Bacterial Pathogens
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Cited by 23 •
2019
This opsonophagocytic killing assay is used to compare the ability of phagocytic immune cells to respond to and kill bacteria based on different treatments and/or conditions. Classically, this assay serves as the gold standard for assessing effector functions of antibodies raised against a bacterium as opsonin.
FAQs
Phagosome–granule fusion brings antimicrobial granule contents into direct contact with engulfed bacteria. This compartmentalized delivery concentrates antimicrobial enzymes and other toxic factors around the captured microbe rather than dispersing them throughout the cell. The process therefore links successful phagocytosis with intracellular bacterial damage and represents a key step in neutrophil-mediated protection against infection.
The oxidative burst generates reactive oxygen species after bacteria have been engulfed. These chemically reactive molecules can damage bacterial membranes and proteins, working alongside antimicrobial enzymes delivered through granule fusion. Examining this pathway helps distinguish the contribution of oxidative chemistry from other intracellular defenses and clarifies why disruption of neutrophil killing mechanisms can increase susceptibility to infection.
Neutrophil extracellular traps, or NETs, provide an extracellular strategy rather than requiring bacteria to remain enclosed inside a phagosome. The traps immobilize microbes and concentrate toxic factors around them. Comparing NET formation with phagocytosis helps explain how neutrophils respond to bacteria in different locations while also connecting antimicrobial activity with possible inflammatory tissue damage.
This process connects innate immune activity with both host protection and disease susceptibility. Studying recognition, engulfment, granule fusion, oxidative damage, and NET release helps investigators identify where antimicrobial defense may fail. Those findings can illuminate immune deficiencies, explain vulnerability to bacterial infection, and clarify how protective inflammation may also contribute to tissue injury.
Studies of these pathways can relate cellular antimicrobial events to broader infection outcomes. They may help explain whether impaired neutrophil function is associated with susceptibility to infection, or whether excessive activity could contribute to inflammatory tissue damage. The same framework supports evaluation of antimicrobial therapies by identifying the host-defense mechanisms such interventions may influence.
Mapping the separate killing mechanisms provides a framework for studying therapies in the context of host defense rather than bacterial growth alone. Investigators can consider effects on phagosome–granule interactions, reactive oxygen species, antimicrobial enzymes, or NET-associated activity. This subject-specific perspective helps connect cellular mechanisms with treatment research and the progression of infection-related disease.