Pathogen Growth Quantification
Pathogen Growth Quantification - Related Videos
07:58
Use of Image Cytometry for Quantification of Pathogenic Fungi in Association with Host Cells
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Cited by 1 •
2013
Here, we demonstrate how image cytometry can be used for quantification of pathogenic fungi in association with host cells in culture. This technique can be used as an alternative to CFU enumeration.
07:47
ScanLag: High-throughput Quantification of Colony Growth and Lag Time
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Cited by 66 •
2014
ScanLag is a high-throughput method for measuring the delay in growth, namely lag time, as well as the growth rate of colonies for thousands of cells in parallel. Screening using ScanLag enables the discrimination between long lag-time and slow growth at the level of a single variant.
11:19
ODELAY: A Large-scale Method for Multi-parameter Quantification of Yeast Growth
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Cited by 4 •
2017
We present a method for quantifying growth phenotypes of individual yeast cells as they grow into colonies on solid media using time-lapse microscopy termed, One-cell Doubling Evaluation of Living Arrays of Yeast (ODELAY). Population heterogeneity of genetically identical cells growing into colonies can be directly observed and quantified.
10:39
Single Cell Measurements of Vacuolar Rupture Caused by Intracellular Pathogens
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Cited by 22 •
2013
We describe a method for tracking the endomembrane rupture elicited by the intracellular bacteria Shigella flexneri and Mycobacterium tuberculosis upon host cell invasion. Our assay makes use of CCF4, a host cytoplasmic FRET probe in live or fixed cells. This reporter is degraded by an enzyme activity present on the bacterial surface.
08:44
Invertebrate Lifespan Quantification
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2023
Many animals naturally stop growing upon reaching adulthood, after which they undergo aging or "senescence" until dying. The amount of time between an organism\'s birth and death is called its lifespan, which can be influenced by various biological and environmental factors. By exposing organisms to different growth conditions, scientists can better understand the factors affecting lifespan. Flies and worms are ideal organisms to perform such experiments, given their short generation time and...
FAQs
Different readouts represent different biological quantities. Serial dilution and plating estimate colony-forming units, linking the measurement to cells capable of producing colonies under the assay conditions. Optical density instead provides an estimate of biomass, while nucleic-acid assays quantify genetic material. Comparing these outputs helps researchers determine whether an observed change reflects viable-cell growth, accumulated biomass, or total detectable material.
Sampling time is central because a single measurement cannot show how abundance changes. Repeated measurements from cultures or samples can be arranged into a growth curve, allowing investigators to compare trajectories under defined biological conditions. Differences between curves can reveal altered growth associated with environmental conditions, host-associated settings, or antimicrobial treatments, rather than simply reporting one endpoint value.
Serial dilution and plating convert a concentrated sample into countable colony-forming units across dilution levels. The resulting counts provide a culture-based measure of viable pathogen abundance, whereas optical density and nucleic-acid assays address different questions about biomass or genetic material. Selecting among these methods, or interpreting them together, prevents one measurement type from being treated as a complete description of growth.
A basic workflow begins by maintaining the pathogen under defined biological conditions, collecting samples at selected time points, and applying a compatible quantitative assay. Researchers then organize measurements over time to generate growth curves and compare conditions or treatments. Consistent sampling is important because changes in timing can alter the apparent trajectory and complicate comparisons among cultures or samples.
Pathogen growth quantification supports several biology research questions. In infection biology, it can compare pathogen behavior in host-associated samples; in antimicrobial evaluation, it can reveal differences between treated and untreated conditions. The same measurements also contribute to food and water safety studies and to investigations of pathogen persistence and transmission.
The most informative interpretation depends on the question being asked. A colony count is suited to tracking viable cells, optical density to estimating biomass, and a nucleic-acid assay to detecting or quantifying genetic material. In studies of persistence or transmission, distinguishing these signals is especially relevant because detectable material does not necessarily represent the same biological quantity as culturable growth.