Thermo Scientific, has launched a new chromogenic culture medium for the enhanced differentiation and presumptive identification of micro-organisms associated with urinary tract infections (UTIs). Thermo Scientific Chromogenic UTI Clarity Agar provides improved colour reactions, allowing clinical laboratories to obtain easily interpreted results faster.

Chromogenic culture media are used increasingly to aid in the diagnosis of UTIs. Since several micro-organisms may be present in a specimen, the use of chromogens helps to distinguish between colonies of different species on a culture plate. However, some chromogenic UTI media do not differentiate enterococci and coliforms by colour. Others exhibit poor recovery of Staphylococcus aureus. Although this species is only responsible for 0.5 – 6% of UTIs, its presence in urine may be an early indication of a pre-existing bacteraemia and so should not be overlooked [1].

Thermo Scientific Chromogenic UTI Clarity Agar allows good growth of the main UTI pathogens, whilst preventing swarming of Proteus species. The new, specific chromogens used in this medium, together with the transparent nature of the medium, allow good differentiation between species, including coliforms (which have dark blue/purple colonies) and enterococci (which have blue/turquoise colonies). It also allows improved recovery of Staphylococcus aureus and correct presumptive identification of Citrobacter freundii, which can be problematic with some other media.

With easily interpreted results available in just 16-24 hours, Thermo Scientific Chromogenic UTI Clarity Agar helps a presumptive diagnosis to be made promptly, allowing patients to receive appropriate treatment at an early opportunity. This may help to improve recovery and reduce complications of UTIs, such as pyelonephritis and bacteraemia.

Fiona Macrae, clinical applications manager, Thermo Scientific, comments, "Thermo Scientific Clarity Agar was developed in response to the need for improved differentiation of the main UTI pathogens. This product complements our existing range of products for the identification of UTI micro-organisms and underpins our dedication to providing fast and reliable microbiological solutions to clinical laboratories."

Thermo Scientific Chromogenic UTI Clarity Agar is available as ready poured plates (PO1110A – UK, PO5159 – rest of Europe) or dehydrated culture medium (CM1106B).

For further information about Thermo Scientific Chromogenic UTI Clarity Agar, please contact Thermo Scientific using the contact details at the top of this page.

Reference: [1] Allan K. Grill, MD, CCFP Sharon Domb, MD, CCFP, "Case Report: Staphylococcus aureus bacteriuria, Important indicator of coexistent bacteremia?", Le Medecin de Famille Canadien, Juin 2004.