Validation and use of liquid Amies transport medium with flocked swab according to document M40-A2 of CLSI.

Abstract

Background: The Amies-gel transport medium with a rayon swab is widely used, but it has been shown that this swab absorbs microorganisms during sample collection, and they are not fully released into the culture medium. There is a new format of liquid Amies with a flocked swab (ESwab®), which would release more microorganisms into the culture medium. In this study we compare both means of transport, determining which is better for microbiological use according to the M40-A2 CLSI document and its use in some clinical samples.Aim: To determine the conservation and recovery  of microorganisms in Amies-gel and liquid media. Methods: Three ATCC strains were studied in both media by qualitative and quantitative method according to document M40-A2 CLSI. Clinical samples (ocular mucous, vaginal discharge and chronic wounds) were also processed, taken in both transport media to compare the count and diversity of microorganisms. Results: The ATCC strains, with the exception of Neisseria gonorrhoeae, were qualitatively and quantitatively validated by both methods. The samples of ocular mucosa and vaginal discharge did not present significant differences between each means of transport, although ESwab® facilitated the reading of the Gram stain. In the case of chronic wounds, ESwab® showed better results than the Amies-gel medium.