Related Experiment Video
Updated: Jun 3, 2026
07:58
Laboratory Techniques Used to Maintain and Differentiate Biotypes of Vibrio cholerae Clinical and Environmental Isolates
Published on: May 30, 2017
Genetic components of stringent response in Vibrio cholerae
Ritesh Ranjan Pal1, Bhabatosh Das, Shreya Dasgupta
1Infectious Diseases & Immunology Division, Indian Institute of Chemical Biology (CSIR), Kolkata, India.
The Indian Journal of Medical Research
|March 19, 2011
Summary
Nutritional stress triggers bacteria
Area of Science:
- Microbiology
- Molecular Biology
Background:
- Nutritional stress induces a stringent response in bacteria, involving gene expression changes.
- This response is mediated by guanosine 3'-diphosphate 5'-triphosphate and guanosine 3',5'-bis(diphosphate) ((p)ppGpp).
- In Vibrio cholerae, (p)ppGpp levels are regulated by relA and spoT genes.
Purpose of the Study:
- To review the roles of genes involved in stringent response in Vibrio cholerae.
- To highlight the novel gene relV and its function in (p)ppGpp synthesis.
- To discuss the involvement of CgtA and DksA in regulating stringent response.
Main Methods:
- Literature review of existing studies on Vibrio cholerae stringent response.
- Analysis of genetic and molecular mechanisms underlying (p)ppGpp synthesis and regulation.
- Examination of the roles of relA, spoT, relV, CgtA, and DksA.
Main Results:
- The stringent response in V. cholerae is primarily regulated by relA and spoT.
- A novel gene, relV, contributes to (p)ppGpp synthesis during nutrient starvation in specific mutant backgrounds.
- CgtA and DksA are important for modulating the stringent response and gene regulation.
Conclusions:
- The stringent response in V. cholerae involves a complex interplay of multiple genes.
- RelV represents a new player in (p)ppGpp synthesis under specific starvation conditions.
- Understanding these regulatory mechanisms is crucial for V. cholerae pathogenesis and control.
Related Concept Videos
01:23Stringent Response in E. coli
Bacterial growth is closely tied to nutrient availability, with cells proliferating exponentially under favorable conditions and entering a stationary phase when resources become scarce. This transition is mediated by a regulatory mechanism known as the stringent response, which allows bacteria to adapt to nutrient deprivation by modulating gene expression and metabolic activity.During nutrient scarcity, intracellular amino acid levels decline. It results in the accumulation of uncharged tRNAs...
01:28Regulation of Bacterial Virulence
Pathogenic bacteria employ a range of regulatory mechanisms to modulate the expression of virulence genes in response to environmental and host-derived signals. These mechanisms ensure that virulence factors are expressed only under favorable conditions, thereby optimizing infection and survival strategies.Mechanisms of Virulence RegulationKey regulatory strategies include:Two-Component Systems: These consist of a membrane-bound sensor kinase and a cytoplasmic response regulator. Environmental...
01:25Cholera
Cholera is an acute gastrointestinal disease caused by the Gram-negative bacterium Vibrio cholerae. It is transmitted primarily via the fecal-oral route through the ingestion of contaminated water or food.Vibrio cholerae is a motile, Gram-negative bacterium of the family Vibrionaceae, primarily associated with waterborne outbreaks in areas with inadequate sanitation. Although over 200 serogroups of V. cholerae exist, only O1 and O139 are responsible for epidemic cholera. The O1 serogroup,...
01:30Other Stress Responses in Bacteria
Bacteria have global regulatory systems that control several types of stress mechanisms. These include Pho regulon and the heat shock response, which are essential systems for environmental adaptation, such as nutrient limitation and proteotoxic stress. The Pho regulon and the heat shock response exemplify bacterial resilience, enabling rapid adaptation to fluctuating environmental conditions.Pho RegulonBacteria require phosphorus for essential cellular processes, including nucleic acid...
01:28Global Regulatory Systems
Global regulatory systems in bacteria enable rapid and coordinated responses to environmental changes by integrating sensory inputs with gene expression, ensuring efficient adaptation to fluctuating conditions. Key global regulatory mechanisms include regulons, two-component systems, sigma factors, and secondary messengers.Regulons and Global RegulatorsA regulon is a collection of genes and operons controlled by a common global regulator. These regulators enable bacteria to prioritize resource...
01:20Determinants of Bacterial Pathogenicity and Virulence
Pathogenic bacteria employ a variety of strategies to establish infections, including the secretion of extracellular enzymes that act as potent virulence factors. These enzymes facilitate bacterial colonization of host tissues and help evade immune surveillance. By targeting structural components of host tissues and interfering with immune mechanisms, these enzymes play a pivotal role in disease progression.Extracellular Enzymes Facilitating Tissue Invasion: Several bacterial pathogens secrete...