Swabs With Transport Medium: An Overview With Product Examples

 To treat a microbial infection, an accurate diagnosis is crucial. In a clinical laboratory, the accuracy of a medical diagnosis begins with two key components: the right tool for collecting a sufficient amount of a sample and careful storage of that sample until it is transferred to a laboratory for analysis. Microbial samples can easily degrade if not properly stored during transport. This is why it is critical to choose the appropriate transport culture media.

In this article, we will define transport media and its components, as well as their varieties and uses.

What is a transport medium?

Transport media are a solution for safely transporting microbial samples to a laboratory for analysis. It is a liquid, balanced buffer solution containing carbohydrates, peptones, and other essential nutrients, except growth factors. A transport medium is used to keep bacteria viable during transport while preventing them from multiplying.

Without an appropriate transport medium and temperature, many bacterial specimens will begin to degrade rapidly. This increases the risk of a false-negative result during analysis in the laboratory.

What are the components of transport media?

Buffers and salt are the only components in transport media. The transport media lack nutritional ingredients such as growth factors, which help prevent microbial multiplication. Antibiotics and other substances, such as glycerol, may be added to transport specimens for tissue culture.

What samples are collected in the transport medium?

All the samples which may contain a pathogen that cannot be processed immediately require transport media. It could be stool, urethral swabs, nasal and throat swabs, tissue culture specimens, and so on.

TM Media Transport Media

To make your microbial analysis easy, TM Media manufactures Ready-To-Use Transport Media with Swabs. This Ready-to-Use Transport Media Tube contains the appropriate media and a swab using which you can collect and transport the microbiological sample to the lab.

Collect the sample with the sterile swab and insert the capped swab into the medium until it reaches the bottom. Tighten the cap completely. The culture medium present in the tube maintains the sample and the viability of the organism during transportation. After reaching the lab, the specimen can be inoculated on the appropriate medium by the pour plate method, filtration, or swabbing.

The transport medium may differ depending on the type of suspected organisms in the sample.

However, in general, microorganism transport media are classified based on their physical, semi-solid, or liquid state as well as their utility as bacterial or viral transport media.

The most commonly used medium for transport is:

• Transport Medium Cary-Blair W/O Charcoal

It is a chemically defined, non-nutritive, low oxidation/reduction potential medium used to maintain the viability of microorganisms such as Neisseria meningitides, Escherichia coli, and Salmonella typhimurium during the collection and transportation of the specimen. 

• Transport Swabs W/Dey-Engley Neutralizing Agar

Dey-Engley Neutralizing Agar is used for the transportation of bacteriological samples from a sanitized surface without causing a significant increase in growth. The medium is recommended for disinfectant testing where the neutralizing agent is important to determine its bactericidal activity. This medium is suitable for Escherichia coli, Bacillus subtilis, Salmonella typhimurium, Pseudomonas aeruginosa, and Staphylococcus aureus. 

• Transport Swabs W/Amies Transport Medium

Amies Medium is a modification of Stuart's Transport Medium. The Amies replace the glycerol phosphate with an inorganic phosphate buffer and provide a reduced environment due to the presence of sodium thioglycollate. The Amies Medium lacks methylene blue. The medium is used to transport Neisseria meningitides, Streptococcus pyogenes, Staphylococcus epidermis, and Staphylococcus aureus.

• Universal Transport Medium W/Glass Beads

The Universal Transport Medium is intended for the collection and transport of clinical specimens containing viruses, chlamydiae, mycoplasmas, or ureaplasmas from the collection site to the testing laboratory. It is a ready-to-use transport swab kit, designed to maintain viral viability and transport viruses in active form for isolation. The peculiar design of the flocked swab ensures optimal elution of the specimen into the transport medium. The Universal Transport Medium contains essential buffers and antibiotics required for maintaining the viability of the viruses during transport. The medium is also recommended by the CDC and WHO for the collection and transport of coronaviruses.

If you’re not sure which transport media might be right for your specific needs or best serve a broad range of uses, TM Media can help. Contact us with your questions at any time.