Salmonella Fitness
Salmonella Fitness - Related Videos
07:11
Digital PCR-based Competitive Index for High-throughput Analysis of Fitness in Salmonella
0 Views •
2019
This molecular-based approach for determining bacterial fitness facilitates precise and accurate detection of microorganisms using unique genomic DNA barcodes that are quantified via digital PCR. The protocol describes calculating the competitive index for Salmonella strains; however, the technology is readily adaptable to protocols requiring absolute quantification of any genetically-malleable organism.
09:01
Chronic Salmonella Infected Mouse Model
0 Views •
Cited by 12 •
2010
Establish a chronic bacterial infected mouse model with persistent Salmonella typhimurium colonization in intestine for 27 weeks.
02:41
Preparation of Salmonella typhimurium Culture
0 Views •
2025
Source: Gutiérrez, S., et. al., Isolation of Salmonella typhimurium-containing Phagosomes from Macrophages. J. Vis. Exp. (2017)This video demonstrates the culturing and preparation of Salmonella typhimurium to obtain a clean, metabolically active bacterial suspension suitable for experimental use.
09:25
Quantification of Cytosolic vs. Vacuolar Salmonella in Primary Macrophages by Differential Permeabilization
0 Views •
Cited by 19 •
2015
We describe the quantification of cytosolic and vacuolar Salmonella typhimurium in bone-marrow derived macrophages using differential digitonin permeabilization.
06:50
A Protocol to Infect Caenorhabditis elegans with Salmonella typhimurium
0 Views •
Cited by 1 •
2014
C. elegans has emerged as a new genetic model to study host-pathogen interactions. Here we describe a protocol to infect C. elegans with Salmonella typhimurium coupled with the double-strand RNAi interference technique to examine the role of host genes in defense against Salmonella infection.
FAQs
Mutations can modify traits that affect growth rate, stress tolerance, nutrient use, or antimicrobial resistance. If a change improves performance in a particular environment, natural selection can increase its representation relative to less suitable variants. The same mutation may offer little advantage, or even become unfavorable, when environmental conditions change, so fitness is context dependent.
Gene regulation changes when and how strongly bacterial traits are expressed, allowing Salmonella variants to respond to environmental conditions without requiring a different set of encoded functions. This can influence nutrient use, stress tolerance, and colonization-related performance. Comparing variants with altered regulation can reveal whether fitness depends on gene activity, not only on the presence of a gene.
Horizontal gene transfer can introduce genetic material between bacteria, whereas mutation changes the existing genetic sequence within a lineage. In Salmonella genetics, either route may alter traits linked to growth, stress tolerance, nutrient use, or antimicrobial resistance. Researchers can evaluate their effects by testing whether the resulting variant performs better in a defined environment.
Environmental conditions determine which genetic variants are favored, because traits that improve performance in one setting may not provide the same advantage elsewhere. For example, differences in nutrient use or stress tolerance can change relative success. Researchers must therefore interpret fitness measurements in relation to the specific host or external environment in which they were obtained.
Competition experiments place genetic variants under the same environmental conditions so their relative performance can be compared directly. Researchers examine which variant shows greater success in reproduction or persistence, rather than judging a strain in isolation. This approach helps connect a genetic difference with an advantage or disadvantage and can identify genes that support colonization.
Growth comparisons indicate whether genetic differences affect the rate at which variants increase, while survival assays examine persistence under the tested conditions. Together, these measurements can distinguish defects in reproduction from defects in continued survival. The resulting patterns help researchers identify genes associated with colonization and persistence and clarify how environmental conditions shape observed fitness.
Fitness measurements can show how genetic changes linked to antimicrobial resistance perform in particular environments, alongside effects on growth, stress tolerance, or nutrient use. These results help researchers track resistance-related traits and understand adaptation in hosts and other settings. Such evidence can also inform interventions aimed at limiting persistence, transmission, or the success of better-adapted variants.