CLINICAL DIPSLIDES

Solar - Cult® Clinical Dipslide

CLED AGAR / EMB LEVINE AGAR

Our MC-400 CLED Agar with Polymyxin B / EMB "Levine" Agar Dipslides are coated with growth media on both sides to increase surface contact with the specimen and enable the use of two different media on each slide. Use of different selective growth media permits simultaneous exposure of a urine specimen to a medium selective for gram-positive species on one side, for example, and to a medium selective for gram-negative species on the other.

EMB Levine Agar

Description

This versatile medium, modified by Levine^1,2, is used for the differentiation of Escherichia coli and Enterobacteria aerogenes, for the rapid identification of Candida albicans, and for the identification of coagulase-positive staphylococci.

The medium is prepared to the formula specified by the APHA^3,4,5,6 for the detection and differentiation of the coliform group of organisms^7,8.

Colonial Characteristics:

Escherichia coli- isolated colonies, 2-3mm diameter, with little tendency to confluent growth, exhibiting a greenish metallic sheen by reflected light and dark purple centres by transmitted light.

Enterobacter aerogenes - 4-6mm diameter, raised and mucoid colonies, tending to become confluent, metallic sheen usually absent, grey-brown centres by transmitted light.

Non-lactose fermenting intestinal pathogens - translucent and colourless.

Candida albicans - after 24 to 48 hours at 35°C in 10% carbon dioxide 'spidery' or 'feathery' colonies. Other Candida species produce smooth yeast-like colonies. Since a typical appearance is variable it is advisable to use a combined method such as that of Walker and Huppert¹⁴.

CLED Agar

Description:

A dehydrated Cystine-Lactose-Electrolyte Deficient (CLED) medium made to the formula described by Mackey and Sandys¹ as a modification for urinary bacteriology of the Electrolyte Deficient Medium developed by Sandys².

This medium is recommended for urinary bacteriology, supporting the growth of all urinary pathogens and giving good colonial differentiations and clear diagnostic characteristics. The presence of important contaminants such as diphtheroids, lactobacilli and micrococci is also clearly elicited, giving an indication of the degree of contamination.

It is electrolyte deficient to prevent the swarming of Proteus species. The medium has been used successfully in the Dip-inoculum Transport Medium technique ( Mackey and Sandys^1,3).

A variant of this technique has been described by Guttman and Naylor⁴ who employed media-coated slides. These techniques overcome false bacteriological results associated with delay in the transport of the specimens of urine to the laboratory and permit a clinically accurate routine differential viable count. They are, therefore, suitable for both general practitioner and hospital work including the screening of ante-natal specimens for symptomless bacteriuria.

For full details, the original papers should be consulted.