Chromogenic UTI Medium, Clear

[所属分类:培养基配方] [发布时间:2020-4-30] [发布人:] [阅读次数:] [返回]

山东拓普生物工程有限公司

Shandong Tuopu Biol-Engineering Co.,Ltd

Chromogenic UTI Medium, Clear

培养基配方

Composition per liter:
Peptone ...................................................................15.0g
Agar.......................................................................15.0g
Chromogenic mix ...........................................................13.0g
pH 7.0 ± 0.2 at 25°C
Source:  This medium is available as a premixed powder from Oxoid
Unipath.
Preparation of Medium: Add components to distilled/deionized
water and bring volume to 1.0L. Mix thoroughly. Gently heat while
stirring and bring to boiling. Autoclave for 15 min at 15 psi pressure–
121°C. Cool to 50°C. Pour into sterile Petri dishes.
Use:  For the presumptive identification and differentiation of all the
main microorganisms that cause urinary tract infections (UTIs). This
medium uses the same chromogenic substrates as the existing opaque
Chromogenc UTI Medium but has a clear background to make multi-
ple sample testing easier. The medium contains two specific chro-
mogenic substrates which are cleaved by enzymes produced by
Enterococcus spp., E. coli, and coliforms. In addition, it contains tryp-
tophan which indicates tryptophan deaminase activity (TDA), indicat-
ing the presence of Proteus spp. It is based on Cystine Lactose Electro-
lyte Deficient (CLED) Medium which provides a valuable non-
inhibitory diagnostic agar for plate culture of other urinary organisms,
while preventing the swarming of Proteus spp. The chromogen, X-glu-
coside, is targeted towards ß-glucosidase enzyme activity, and allows
the specific detection of enterococci through the formation of blue col-
onies. The other chromogen, Red-Galactoside, is cleaved by the
enzyme ß-galactosidase which is produced by E. coli, resulting in pink
colonies. Cleavage of both the chromogens by members of the coli-
form group results in purple colonies. The medium also contains tryp-
tophan which acts as an indicator of tryptophan deaminase activity
(TDA), resulting in halos around the colonies of Proteus, Morganella,
and Providencia spp.