Related Experiment Video
Updated: Aug 7, 2026
11:13
Culturing and Maintaining Clostridium difficile in an Anaerobic Environment
Published on: September 14, 2013
Clostridium difficile: isolation and characteristics
Journal of Medical Microbiology
|May 1, 1976
Summary
Clostridium difficile isolation is optimized using Reinforced Clostridial Medium (RCM) with phenol or p-cresol. This study details its growth, fermentation, and toxin production for better identification.
Area of Science:
- Microbiology
- Bacteriology
Background:
- Clostridium difficile is an important human pathogen.
- Efficient isolation and identification methods are crucial for clinical and research settings.
Purpose of the Study:
- To optimize the isolation medium for Clostridium difficile.
- To characterize the biochemical and antigenic properties of Clostridium difficile strains.
Main Methods:
- Cultivation of Clostridium difficile in Reinforced Clostridial Medium (RCM) supplemented with varying concentrations of cresols and phenol.
- Assessment of growth characteristics, including "cornfield" morphology.
- Fermentation studies using various carbohydrates.
- Detection of enzyme production (hyaluronidase, deoxyribonuclease) and biochemical reactions (nitrate reduction, indole production, gelatin liquefaction).
- Antigenic analysis of bacterial strains.
Main Results:
- Reinforced Clostridial Medium (RCM) with 0.2% phenol or p-cresol is recommended for Clostridium difficile isolation.
- Characteristic "cornfield" growth observed in RCM.
- Specific fermentation patterns identified: acid and gas production from glucose, fructose, galactose, mannose, raffinose, aesculin, and mannitol; acid only from maltose, sucrose, glycogen, soluble starch, and sorbitol.
- Lactose and rice starch were not fermented; DL-methionine was not utilized.
- Nitrate reduced to nitrite; hydrogen sulfide and indole were not produced.
- Gelatin liquefaction observed, with variable incubation times.
- Hyaluronidase produced, but deoxyribonuclease was not.
- Evidence suggests lethal toxin production.
- Strains exhibited shared and strain-specific antigens.
Conclusions:
- Optimized RCM formulation enhances Clostridium difficile isolation.
- Detailed biochemical profile aids in differentiating Clostridium difficile from other bacteria.
- Understanding toxin production and antigenic properties is vital for pathogenesis and vaccine development.
Related Concept Videos
01:17Transmission-based Precautions I: Contact, Enteric, and Droplets
Transmission-based precautions are for patients known to be infected or suspected to be infected or colonized with organisms that pose a significant risk to others. Some transmission-based precautions include contact, enteric, and droplet.
Contact Precautions:
Contact precautions are the measures taken to prevent the transmission of infectious agents, especially epidemiologically important microorganisms such as MRSA or influenza, primarily transmitted through direct or indirect contact with an...
Contact Precautions:
Contact precautions are the measures taken to prevent the transmission of infectious agents, especially epidemiologically important microorganisms such as MRSA or influenza, primarily transmitted through direct or indirect contact with an...
01:20Endospores and Sporulation
Endospores are specialized, dormant cells primarily formed by Gram-positive bacteria, including Bacillus and Clostridium, enabling survival under extreme environmental conditions. Due to their unique composition and formation process, these structures are highly resistant to physical and chemical insults, such as extreme heat, ultraviolet and ionizing radiation, desiccation, and toxic chemicals. Rare instances of endospore-like structures have also been observed in some Gram-negative bacteria,...
01:24Techniques for Isolation of Pure Cultures
Microorganisms are routinely cultured in the laboratory using various techniques to isolate, grow, and quantify them for further study. These methods rely on inoculating microorganisms into a suitable growth medium under aseptic conditions to prevent contamination. Depending on the objective, inoculation can involve direct transfer or the use of diluted bacterial suspensions as the inoculum.Streak-Plate Method for IsolationThe streak-plate method is a common technique for obtaining pure...
01:30Bacterial Phylum Actinobacteria
Coryneform bacteria are gram-positive, aerobic, nonmotile rods that exhibit irregular, club-shaped, or V-shaped arrangements. Their V-shape results from snapping division, where the inner cell wall layer forms the cross-wall, while the outer layer remains intact until it ruptures on one side, causing the daughter cells to bend away.The primary genera are Corynebacterium and Arthrobacter. Corynebacterium includes diverse species, ranging from saprophytes to pathogens like Corynebacterium...
01:18Bacterial Gastroenteritis
Bacterial gastroenteritis, characterized by diarrhea, abdominal cramps, and vomiting, is often caused by ingestion of contaminated food or water and is frequently associated with pathogenic Escherichia coli strains. These microbes exploit two principal mechanisms to inflict disease.Shiga toxin–producing E. coli, also referred to as STEC—notably O157:H7—release Shiga toxins that target ribosomes, blocking protein synthesis. The B subunit of the toxin binds the host glycolipid receptor...
01:25Clinical Significance of Antibiotic Resistance
Methicillin-resistant Staphylococcus aureus (MRSA) presents a critical public health threat, arising from its capacity to resist β-lactam antibiotics due to acquisition of the mecA gene within the staphylococcal cassette chromosome mec (SCCmec). This gene encodes penicillin-binding protein 2a (PBP2a), which impairs binding efficacy of methicillin and other β-lactams. MRSA has evolved into distinct clonal lineages impacting humans and animals alike, reinforcing its significance within the One...