Chromogenic Urinary Tract Infection (UTI) Medium

[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 Urinary Tract Infection (UTI) Medium

培养基配方
Composition per liter:
Chromogenic mix ................................................................26.3g
Peptone ........................................................................15.0g
Agar............................................................................15.0g
pH 6.8 ± 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). The
medium contains two specific chromogenic substrates which are
cleaved by enzymes produced by Enterococcus spp., Escherichia coli,
and coliforms. In addition, it contains phenylalanine and tryptophan
which provide an indication of tryptophan deaminase activity, indicat-
ing the presence of Proteus spp., Morganella spp., and Providencia
spp. It is based on electrolyte deficient CLED Medium which provides
a valuable non-inhibitory diagnostic agar for plate culture of other uri-
nary organisms, while preventing the swarming of Proteus spp. One
chromogen, X-Gluc, is targeted towards β-glucosidase, and allows the
specific detection of enterococci through the formation of blue colo-
nies. The other chromogen, Red-Gal, is cleaved by the enzyme β-
galactosidase which is produced by Escherichia coli, resulting in pink
colonies. Cleavage of both chromogens occurs in the presence of coli-
forms, resulting in purple colonies. The medium also contains trypto-
phan which acts as an indicator of tryptophan deaminase activity,
resulting in colonies of Proteus, Morganella, and Providencia spp.
appearing brown.