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.
|Description||HBT Bilayer Medium|
|Format||12mm x 85mm Monoplate|
|Catalog Number||Specifications||Unit Size||dimFormat||Price (USD)|
|R01478||Each||Request A Quote|
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.
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.