Intracellular Bacteria Quantification
Intracellular Bacteria Quantification - Related Videos
01:33
Investigating Autophagy-Mediated Clearance of Intracellular Bacteria In Vitro
0 Views •
2026
Take pig kidney cell cultures, with one culture pre-treated with an inhibitor that increases lysosomal pH, impairing autophagic-lysosomal degradation.Add pathogenic bacteria and centrifuge to enhance host-pathogen contact.Incubate to allow bacterial invasion and internalization into endocytic vesicles.The internalized bacteria consume host nutrients to replicate, triggering metabolic stress.This stress activates autophagy, where an autophagic membrane expands around the vesicle, forming an...
01:10
Intracellular Movement of Viruses and Bacteria
0 Views •
2023
Intracellular bacteria and viruses often comprise a group of highly infectious pathogens that can cause several diseases. Bacterial pathogens include those belonging to the genus Rickettsia responsible for conditions such as rocky mountain spotted fever and the Mediterranean spotted fever; Chlamydia, a genus responsible for a sexually transmitted disease; Coxiella burnetii, an agent responsible for Q fever. Viral pathogens include vaccinia—a poxvirus, and herpes simplex virus—a virus that...
03:41
Isolation of Intracellular Pathogenic Bacteria from Infected Host Cells
0 Views •
2026
Source: Sigal, N., et al. RNA Purification from Intracellularly Grown Listeria monocytogenes in Macrophage Cells. J. Vis. Exp. (2016).This video demonstrates the isolation of internalized pathogenic bacteria from infected bone marrow-derived macrophages (BMDMs). Bacteria are allowed to attach to host cells, and unattached bacteria are washed away. After internalization, an antibiotic is added to eliminate non-internalized bacteria. The host cells are lysed, centrifuged, and the supernatant is...
03:16
An Assay for the Quantification of Inorganic Polyphosphate in Bacteria
0 Views •
2025
Source: Pokhrel, A., et al. Assaying for Inorganic Polyphosphate in Bacteria. J. Vis. Exp. (2019).This video demonstrates a colorimetric assay to measure inorganic polyphosphate (polyP) in bacterial samples. The procedure involves enzymatically converting polyP into free phosphate, which then reacts with molybdate and ascorbic acid to produce a blue-colored complex. By comparing the absorbance of this complex to a standard curve of known phosphate concentrations, the polyP content in bacterial...
15:28
A Microscopic Phenotypic Assay for the Quantification of Intracellular Mycobacteria Adapted for High-throughput/High-content Screening
0 Views •
Cited by 30 •
2014
Here, we describe a phenotypic assay applicable to the High-throughput/High-content screens of small-interfering synthetic RNA (siRNA), chemical compound, and Mycobacterium tuberculosis mutant libraries. This method relies on the detection of fluorescently labeled Mycobacterium tuberculosis within fluorescently labeled host cell using automated confocal microscopy.
FAQs
Intracellular bacteria quantification relies on gentamicin’s differential access to bacteria outside versus inside host cells. The antibiotic eliminates extracellular organisms, whereas bacteria within host cells remain protected during that treatment. This separation makes the subsequent cell-lysis step informative: recovered organisms are attributed to the intracellular compartment rather than to bacteria still present externally.
An intracellular burden measurement can reflect several infection outcomes, including bacterial entry, persistence, or replication. Consequently, the result should be interpreted according to the biological question and experimental comparison being made. A difference between conditions may indicate altered host-cell interaction, antimicrobial activity, or immune influence, rather than representing only one stage of infection.
Colony formation and molecular detection answer related but not identical questions. Colony-based recovery provides a count of organisms that can produce colonies after host-cell lysis, while genetic detection supplies a complementary measurement of bacterial material. Using both, alongside microscopy, can help distinguish changes in recoverable burden from visual evidence of pathogen-host-cell interactions.
Host-cell identity is an important variable in intracellular bacteria quantification. The same pathogen or treatment can be examined across different cell types, allowing researchers to assess whether intracellular persistence or antimicrobial effects depend on cellular context. This comparison is especially relevant in immunology and infection studies, where cell type forms part of the host-response context.
In a gentamicin protection workflow, researchers expose infected host cells to gentamicin so extracellular bacteria are eliminated, then lyse the host cells to release protected organisms. The recovered material is quantified by colony formation or by a complementary molecular method. Keeping the antibiotic-treatment, lysis, and measurement stages conceptually separate helps connect the final readout to intracellular bacterial burden.
Researchers apply this measurement to test antimicrobial activity, evaluate intracellular persistence, and examine how host immune responses affect bacterial burden. It can also support comparisons among treatments or host-cell types. In infection research, the readout is most informative when paired with microscopy or genetic detection, because those complementary approaches can clarify how the measured burden relates to pathogen-host-cell interactions.