Скачать или смотреть Transport Media I Types and Composition I Different Types of Bacterial Culture Media I Microbiology

Transport media are specialized media that preserve microorganisms during transport without allowing them to multiply. Common examples are Stuart’s medium, Amies medium, Cary-Blair medium, VR medium, Viral Transport Medium, and Anaerobic Transport Medium.
Transport media are specially formulated media used to maintain the viability of microorganisms during collection, transport, and processing of clinical specimens, without allowing them to multiply.

They do not contain growth-promoting nutrients, but contain substances to preserve microbes and inhibit contaminant overgrowth.

👉 Purpose: Safe transfer of specimens like throat swabs, stool, urine, pus, and blood samples to the laboratory.

2. Characteristics of Transport Media

Maintain moisture and pH balance.

Contain buffers and salts, but lack nutrients for growth.

Prevent desiccation (drying) of the sample.

May contain antibiotics or charcoal to suppress contaminants or neutralize toxins.

Essential for pathogens that are fragile outside the body (e.g., Neisseria, Shigella).

3. Types of Transport Media (Examples)
A. Stuart’s Transport Medium

Semi-solid medium.

Contains minimal nutrients, buffer, and a reducing agent.

Used for Neisseria gonorrhoeae, Haemophilus, Streptococcus.

B. Amies Transport Medium

Modification of Stuart’s medium.

Available with or without charcoal.

Charcoal neutralizes fatty acids and toxic substances.

Used for Neisseria, Haemophilus, anaerobes.

C. Cary-Blair Transport Medium

Semi-solid medium.

High pH (alkaline) → enhances survival of enteric pathogens.

Used for Salmonella, Shigella, Vibrio, Campylobacter.

D. Venkatraman-Ramakrishnan (VR) Medium

Used for Vibrio cholerae transport.

E. Viral Transport Medium (VTM)

Contains buffer, protein stabilizers, and antibiotics.

Used for viruses (e.g., influenza, SARS-CoV-2, herpes viruses).

F. Anaerobic Transport Medium

Contains reducing agents to maintain anaerobic conditions.

Used for Clostridium, Bacteroides and other anaerobes.

4. Summar

Transport Media (with examples):

Stuart’s Medium → For Neisseria, Streptococcus, Haemophilus.

Amies Medium (with/without charcoal) → For Neisseria, Haemophilus, anaerobes.

Cary-Blair Medium → For enteric pathogens: Salmonella, Shigella, Vibrio, Campylobacter.

VR Medium → For Vibrio cholerae.

Viral Transport Medium (VTM) → For influenza, coronaviruses, herpes viruses.

Anaerobic Transport Medium → For Clostridium, Bacteroides.

5. Key Points

Transport media ≠ growth media → they maintain viability only.

Choice of transport medium depends on specimen type & suspected organism.

Crucial for accurate diagnosis in clinical microbiology.