Your One-stop Source For Everything Amies Transport Medium

Doctor hands with surgical gloves, medium transport tubes for pcr analysis, in cardboard holder, blue background

Welcome to our guide on everything you need to know about Amies transport medium. If you work in microbiology, you're probably familiar with Amies transport medium - it's a widely used transport medium for the collection and preservation of clinical specimens for bacterial culture. This medium is designed to keep microorganisms viable during transit from the collection site to the laboratory for processing and analysis.

In this article, we'll give you an overview of Amies transport medium, including its composition, uses, preparation, principle, storage condition, etc.

I. What is Amies Transport Medium

Amies medium is a semi-solid transport medium used to collect, transport, and preserve clinical specimens, as well as for long-term storage in a freezer. It maintains the viability of microorganisms without significantly increasing growth. The formulation was introduced by Stuart et al. in 1954 and is a modification of Stuart transport medium, which replaces glycerophosphate with inorganic phosphate buffer and adds charcoal to the medium. Charcoal may be included in the Amies formulation, as it has been shown to increase the survival of gonococci in the transport medium.

Composition of Amies transport medium

Ingredients	Gms/litre
Sodium chloride	3.0
Potassium chloride	0.2
Calcium chloride	0.1
Magnesium chloride	0.1
Monopotassium phosphate	0.2
Disodium phosphate	1.150
Sodium thioglycollate	1.0
Charcoal	10.0
Agar	4.0

II. Uses of Amies Transport Medium

Amies transport medium is utilized to collect, transport, and preserve microbiological specimens, particularly those from throat, vaginal, and wound swab samples. It is frequently utilized to transport specimens from collection centers or healthcare facilities to microbiology laboratories.

1. Nasopharyngeal specimen: A nasopharyngeal swab specimen is collected to identify carriers of N. meningitidis. The specimen is then transported to the laboratory in Amies or Stuart’s medium or directly plated onto medium and transported in a CO2 containing the system. Amies medium is also used in suspected cases of Bordetella pertussis and Corynebacterium diphtheriae.
2. Urogenital swab: To transport urethral, cervical, and vaginal swabs efficiently, use Amies medium. This guarantees the survival of delicate organisms like Neisseria gonorrhoeae as well as Haemophilus ducreyi, which causes soft chancre.
3. Sputum: Take a purulent part of the sputum and put it on a cotton-wool swab, then place it in a container of Amies transport medium. Amies medium is used to help pathogens like S.pneumoniae and H. influenzae survive, while also preventing the overgrowth of fast-multiplying commensals.
4. Pus Samples: To collect a pus specimen, use a sterile cotton-wool swab. If there is no discharge, use a sterile cotton swab to collect a sample from the infected site. Place the swab in a container of Amies transport medium. Break off the swab stick to allow the bottle top to be replaced tightly.

III. Preparation of Amies Transport Medium

To prepare the best Amies transport medium, use a dehydrated powder that's already prepared and can be obtained from most suppliers of culture media.

1. In order to prepare the Amies transport medium, dissolve the necessary quantity in distilled water and mix thoroughly.
2. Pour the medium into bottles with screw caps.
3. Autoclave the bottles at 121C for 15 minutes with the cap loosened.
4. Once the medium has cooled, securely tighten the bottle cap and label with the date and batch number. While storing, periodically invert the bottle to ensure the charcoal is evenly distributed.
5. The Amies transport medium can be used for up to 12 months when stored.

IV. Storage and Shelf Life of Amies Transport Medium

Store the product in a tightly closed container between 10-30°C, and store the prepared medium at 5-25°C. Be sure to use the product before the expiry date on the label. After opening, make sure to store the product in a dry area and tightly cap the bottle to avoid lump formation, as the product is hygroscopic. Improper storage of the product may lead to lump formation. Keep the container sealed tightly after use, and store the product in a dry and ventilated area that is protected from extreme temperatures and sources of ignition. For the best performance, use the product within its stated expiry period.

V. Comparing Amies Transport Medium to Other Transport Media

Amies mediums are crucial for transporting microbiological specimens. The medium contains inorganic phosphates that help maintain the osmotic balance of the specimen by providing a buffer. Cary Blair mediums are particularly useful for preserving and transporting samples such as stool and rectal swabs.

Amies is a Stuart transport medium that has been modified by replacing glycerophosphate with an inorganic phosphate buffer and adding charcoal to the medium. The modification resulted in a higher percentage of positive results compared to the original Stuart transport medium.

VI. Principle and Use Instruction of Amies Transport Medium

The transport medium can be semi-solid, non-nutritive, and reducing to prevent self-destructive enzymatic reactions. Amies Transport Medium meets these requirements by containing sodium thioglycolate and a small amount of agar that create a reduced environment. Additionally, charcoal neutralizes toxic substances that are harmful to pathogens like Neisseria gonorrhoeae. Salts help the survival of gonococcal cells and regulate the permeability of bacterial cells. Finally, the phosphate buffer maintains the medium's pH.

Instruction of Use:

1. To collect a sample, insert the sterile swabs into the upper third of the transport medium in the container provided for transport.
2. Snap off the protruding part of the swab and screw it in tightly.
3. Send the sample to the lab within 24 hours for cultural analysis.
4. Rest assured that samples can be safely stored in the refrigerator until you are ready to ship them.

Mantacc Amies Transport Medium

Looking for a reliable and versatile transport medium for your clinical specimens? Look no further than Mantacc Amies Transport Medium. Our medium is specially designed to maintain the viability of a wide range of bacteria, including E. coli, Shigella, Salmonella, Staphylococcus aureus, Streptococcus pyogenes, and Streptococcus pneumoniae, among others. With Mantacc Amies Transport Medium, you can collect and transport various clinical samples, such as throat swabs, nasal swabs, rectal swabs, urine, secretions, and tissue samples with ease and confidence. Our medium is available in different types to suit your specific needs and can keep microorganisms alive even in adverse environmental conditions. Trust Mantacc Amies Transport Medium for your microbiological needs and get reliable results for your clinical practice or research.