4), this particular strain has the same colony appearance as other Salmonella isolates – distinctive red colonies.īecause of the risks associated with reporting false negative results with such atypical Salmonella strains, ISO-6579 (Microbiology of the food chain - Salmonella) requires laboratories to use XLD agar and a second selective media of your choosing. Hektoen Enteric Agar (HEA) was developed in 1967 by King and Metzger of the Hektoen Institute in order to improve the isolation of Shigella and Salmonella organisms when compared with other media frequently utilized at that time.1,2 This medium is considered to be moderately selective, and is particularly useful in the isolation of Shigella spec. 3) and CHROMagar™ Salmonella Plus (see Fig. Such colony characteristics on XLD would result in these Salmonella isolates being reported as a false negative (as their appearance is typical of a coliform isolate).Īs shown below when grown on Rambach™ agar (see Fig. RESULTS A total of 1027 rectal swabs from diarrheal patients were. 12947178 X10 Xld agar (special), 90mm ready poured plate - Thermo Scientific Oxoid £25.35 / Pack of 10 Customers who viewed this item also viewed Viewing 1 - 3 of 13 Catalog No. Salmonella-Shigella, and xylose lysine deoxycholate agar for isolation of Shigella. These Salmonella colonies are yellow without the black dot (see Fig.2 above), instead of the expected red with a black dot for a typical Salmonella (see Fig.1 above). Xylose Lysine Deoxycholate (XLD) Agar (NCM0027) Intended Use Xylose Lysine Deoxycholate Agar is used for the isolation and differentiation of enteric pathogens. Specifications SDS Documents Special Offers You may be interested in these alternatives Product Code. ![]() acidify the medium, a result of sugar fermentation. These characteristics lead to an atypical colony appearance on this media. XLD (Xylose Lysine Desoxycholate) Agar is used mainly for the isolation of Salmonella and Shigella. The particular strain of Salmonella implicated in the recent contamination of infant formula milk, is from the S.agona species group and has very unusual behaviour on XLD, ie non-alkalinisation of the medium and no H2S reaction.
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