Related Experiment Video
Updated: May 13, 2026
08:38
Oral Transmission of Listeria monocytogenes in Mice via Ingestion of Contaminated Food
Published on: May 6, 2013
Listeria monocytogenes ArcA contributes to acid tolerance
Changyong Cheng1, Jianshun Chen2, Ying Shan1
1Zhejiang University Institute of Preventive Veterinary Medicine and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, 388 Yuhangtang Road, Hangzhou, Zhejiang 310058, PR China.
Journal of Medical Microbiology
|March 23, 2013
Summary
Listeria monocytogenes requires the arcA gene for survival in acidic environments, such as the stomach. Deleting arcA reduces Listeria monocytogenes virulence in mice.
Area of Science:
- Microbiology
- Pathogen Biology
- Molecular Biology
Background:
- Listeria monocytogenes is a foodborne pathogen that colonizes the intestinal tract and can cause systemic infections.
- Survival and adaptation to the low pH of the stomach are critical for L. monocytogenes to establish infection.
- The arginine deiminase pathway is a known mechanism for acid tolerance in bacteria.
Purpose of the Study:
- To investigate the role of the L. monocytogenes gene lmo0043 (orthologue of arcA) in acid tolerance and virulence.
- To characterize the function of ArcA in surviving acidic conditions and its impact on infection models.
Main Methods:
- Gene sequence analysis to identify conserved motifs in lmo0043.
- In vitro growth assays under various acidic conditions (pH 5.5, pH 2.5).
- Murine infection models (gastric and intraperitoneal inoculation) to assess survival and bacterial load.
Main Results:
- Transcription of arcA increased significantly under acid stress (pH 4.8).
- Deletion of arcA impaired L. monocytogenes growth at pH 5.5 and reduced survival in synthetic gastric fluid (pH 2.5) and the murine stomach.
- Mice infected with an arcA deletion mutant showed significantly lower bacterial load in the spleen compared to wild-type.
Conclusions:
- L. monocytogenes arcA is essential for acid tolerance in vitro.
- ArcA plays a crucial role in gastric survival and contributes to virulence in a murine model.
- Genetic complementation restored the wild-type phenotype, confirming arcA's role.
Related Concept Videos
01:27Microbes in the Production of Fermented Foods
Lactic acid bacteria (LAB) and molds are instrumental in fermenting plant-based foods to enhance preservation and ensure year-round availability. These microbial processes convert plant carbohydrates into organic acids and other metabolites that inhibit spoilage organisms and contribute to the sensory qualities of the final product.In sauerkraut production, cabbage goes through a microbial succession that starts with cocci such as Leuconostoc mesenteroides. These microbes begin fermentation by...
01:29Microbes in Food Production
Microbial fermentation is central to food biotechnology, enhancing flavor, texture, preservation, and stability. Fermentative microorganisms metabolize carbohydrates into organic acids, alcohols, and other metabolites that inhibit spoilage organisms and improve digestibility while contributing distinctive sensory qualities.In baking, amylases naturally present in flour hydrolyze starch into monosaccharides such as glucose, which Saccharomyces cerevisiae ferments anaerobically. Through...
01:25Production of Organic Acids
Lactic acid, an important organic acid extensively applied in food, pharmaceutical, and biodegradable polymer industries, is primarily produced via microbial fermentation. This method is favored over chemical synthesis due to its environmental sustainability and capacity for enantiomerically pure product formation. Among various microbial processes, the fermentation of starch-based substrates stands out due to the abundance and renewability of raw materials like corn and potatoes.Hydrolysis of...
01:27Microorganisms in Agriculture and Food industry
Microorganisms play a crucial role in agriculture and the food industry, contributing to soil fertility, crop protection, and food production. Their functions range from nitrogen fixation and biopesticide production to fermentation and food preservation, making them indispensable to sustainable farming and food safety.Role in AgricultureNitrogen-fixing bacteria, such as Rhizobium (symbiotic) and Azotobacter (free-living), convert atmospheric nitrogen into ammonia through biological nitrogen...
01:23Microbial Fermentation
Fermentation is a crucial anaerobic metabolic process that enables microbes to derive energy from sugar without relying on oxygen or an electron transport chain. This process is fundamental to various biological and industrial applications and is classified based on the metabolic products generated.Role of Pyruvate in FermentationPyruvate and its derivatives serve as key electron acceptors in fermentative pathways. The oxidation of NADH to regenerate NAD+ is essential for the continuation of...
01:27Microbiota of the Stomach and Small Intestine
The human gastrointestinal (GI) tract is characterized by distinct physicochemical conditions that shape its microbial communities. Among these, the stomach presents a particularly challenging environment for microbial colonization due to its highly acidic pH, ranging from 1 to 3. This extreme acidity effectively limits microbial density. However, certain acid-tolerant microorganisms are capable of surviving in this niche. Notably, Helicobacter pylori can colonize the gastric mucosa,...