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Thermo Scientific™ HBT Bilayer Medium
Description
Selectively isolate and presumptively identify Gardnerella vaginalis using HBT Bilayer Medium (Human Blood-Polysorbate 80).
Selectively isolate and presumptively identify Gardnerella vaginalis using Thermo Scientific™ Remel™ HBT Bilayer Medium (Human Blood-Polysorbate 80). Media used by earlier investigators to recover G. vaginalis from clinical specimens include chocolate agar, peptone starch dextrose (PSD) agar, and Columbia colistin nalidixic acid agar1-3. Greenwood and Pickett developed V agar and demonstrated that G. vaginalis is a beta-hemolytic on agar containing human blood but not on sheep blood agar4,5.
Gardnerella vaginalis is a gram-variable rod or coccobacillus. It is a venereally transmitted bacterium that causes bacterial vaginosis6. This is a condition characterized by an increase in the numbers of G. vaginalis and various obligate anaerobes, and a concomitant decrease in lactobacilli observed on gram-stained smears. HBT Bilayer Medium, formulated by Totten et al., consists of a bottom layer of Columbia colistin nalidixic acid agar supplemented with peptone, amphotericin B, and polysorbate 80 together with a top layer of the same media with 5% human blood added7. It shows significantly higher isolation rates of G. vaginalis than those obtained with other media.
Use HBT BiLayer Medium for selective and presumptive identification of Gardnerella vaginalis.
- Ready to use – Convenience of prepared media
- Selective medium - Colistin, nalidixic acid, and amphotericin B are selective agents that inhibit most gram-negative rods, yeast, and diphtheroids
- Easy to interpret - G. vaginalis produces small, opaque colonies surrounded by a diffuse zone of beta-hemolysis
The casein and meat peptones supply nutrients. Phosphate buffer maintains pH and cornstarch neutralizes toxic fatty acids. Polysorbate 80 enhances the diffusion of beta-hemolysis. The top layer contains the same medium with addition of 5% human blood. Since the zones of beta-hemolysis are viewed through a shallow layer of blood-containing medium, hemolysis is more distinct and easier to detect than with a single layer medium.

Specifications
Specifications
Description | HBT Bilayer Medium |
Format | 12mm x 85mm Monoplate |
Product Type | Agar |
Quantity | 10/Pk. |
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