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Updated: Jan 15, 2026
Culturing and Maintaining Clostridium difficile in an Anaerobic Environment
Published on: September 14, 2013
pH-Dependent Effects of Short-chain Carboxylic Acids and Buffer Systems On Clostridioides difficile in Vitro and in
Lucía Huertas-Díaz1, Jiri Hosek1, Ditte Gram-Hansen1
1Department of Biological and Chemical Engineering, Aarhus University, Gustav Wieds Vej 10, 8000, Aarhus C, Denmark.
Insights
Clostridioides difficile colonization in infants is influenced by gut chemistry. Near-neutral pH and specific short-chain carboxylic acids (SCCA) impact its prevalence and growth, suggesting new ways to control C. difficile.
Area of Science:
- Microbiology
- Gastroenterology
- Environmental Health
Background:
- Clostridioides difficile (C. difficile) is an opportunistic pathogen that colonizes the infant gut early in life.
- Environmental factors within the infant gut significantly influence C. difficile prevalence and physiology.
- Understanding these factors is crucial for managing C. difficile colonization.
Purpose of the Study:
- To investigate the impact of infant gut environmental conditions, specifically pH and short-chain carboxylic acids (SCCA), on C. difficile prevalence and physiology.
- To elucidate the role of buffering systems in modulating C. difficile's response to SCCA.
- To identify potential targets for controlling C. difficile colonization.
Main Methods:
- Combined in vitro and in vivo analyses using experimental and modeling approaches.
- Examined the effects of varying pH, SCCA concentrations, and phosphate buffer systems on C. difficile.
- Utilized multilinear regression models to analyze in vitro and in vivo data.
Main Results:
- C. difficile prevalence increased significantly in infants from 3 to 12 months.
- Optimal C. difficile growth occurred at pH 5.8-6.3 in vitro.
- SCCA exhibited antimicrobial activity at lower pH but promoted growth at pH 6.5; phosphate buffers enhanced SCCA antimicrobial activity.
- In vivo, C. difficile abundance correlated inversely with undissociated SCCA.
Conclusions:
- Gut chemical environments, including pH, buffer systems, and the state of SCCA, significantly affect C. difficile occurrence and performance.
- The findings suggest novel strategies targeting these chemical systems to modulate C. difficile colonization.
- This research provides insights into the complex interplay between the infant gut microbiome and C. difficile.
Abstract:
The spore-forming anaerobe Clostridioides difficile colonizes the highly dynamic gut environment early after birth, frequently without causing disease. In this study, we aimed to determine how environmental conditions indicative of the infant gut impacted prevalence and physiology of C. difficile. We examined the effect of pH, fermentation derived short-chain carboxylic acids (SCCA) and buffering systems combining in vitro and in vivo analysis, and experimental and modelling approaches. In vivo, the prevalence of Clostridioides significantly increased between 3 months (30.2%) and 12 months (56.2%) after birth. At 12 months, the occurrence of Clostridioides was the highest in feces with near neutral pH (6.7 (IQR 6.5‒7.3). In vitro, C. difficile showed pH-dependent growth and metabolic activity with an optimum around pH 5.8–6.3. Most SCCA conferred antimicrobial activity at pH 5.2 and 6.1 while at pH 6.5, high concentrations of SCCA promoted growth. The presence of phosphate buffer enhanced antimicrobial activity of SCCA, particularly at lower pH values (5.2–5.8). Two multilinear regression models indicated that ionic strength was inversely related to optical density in vitro, while in vivo, the abundance of Clostridioides was inversely linked to the presence of undissociated SCCA. Together, this study highlights that the that occurrence and performance of the opportunistic pathogen C. difficile was affected by chemical systems such as pH, the presence of buffer systems and concentration and chemical state of SCCA. Our results suggest novel targets that could be modulated to impact C. difficile colonization.
