Fastidious organism

A Fastidious organism is a type of microorganism that has complex nutritional requirements. In other words, these organisms need specific nutrients to grow that are not easily available in nature or in standard laboratory media. Fastidious organisms are often associated with specific diseases in humans and animals.

Characteristics

Fastidious organisms are characterized by their need for special nutritional or environmental conditions for growth. They require specific nutrients, such as certain vitamins, amino acids, or growth factors, which are not readily available in nature or in standard laboratory media. These organisms are often difficult to culture in the laboratory due to their specific growth requirements.

Types of Fastidious Organisms

There are several types of fastidious organisms, including:

• Haemophilus influenzae: This bacterium is a common cause of meningitis and respiratory tract infections in children. It requires hemin (factor X) and NAD (factor V) for growth.

• Neisseria gonorrhoeae: This bacterium causes gonorrhea, a sexually transmitted infection. It requires a rich medium with numerous growth factors for growth.

• Campylobacter jejuni: This bacterium causes gastroenteritis, and requires a microaerophilic environment for growth.

Clinical Significance

Fastidious organisms are often associated with specific diseases in humans and animals. For example, Helicobacter pylori is a fastidious organism that is associated with peptic ulcer disease and gastric cancer. Similarly, Mycoplasma pneumoniae is a fastidious organism that is a common cause of pneumonia.

Culturing Fastidious Organisms

Culturing fastidious organisms can be challenging due to their specific growth requirements. Specialized media, such as chocolate agar, Thayer-Martin agar, or Martin-Lewis agar, are often used to culture these organisms. In addition, some fastidious organisms require a specific atmosphere for growth, such as a microaerophilic or anaerobic environment.

See Also

• Microbiology
• Bacteriology
• Pathogen