OxyPRAS Plus® BBE Agar Plate
Price
$2.80 – $26.69
Product Options:
P-BBE-10 – (10 plates per pack) – $25.91
Additional information
Product Information
OxyPRAS Plus® BBE Agar Plate
OxyPRAS Plus® BBE Agar is a pre-reduced anaerobically sterilized (PRAS) Bacteroides bile esculin agar plate for the selective isolation and presumptive identification of the Bacteroides fragilis group from clinical specimens. Oxbile and gentamicin hold back most other organisms, and B. fragilis group members that grow hydrolyze esculin and turn the surrounding medium black to brown. The plate arrives ready to inoculate with no post-reduction step.
At a glance
Catalog number: P-BBE-NB (single plate), P-BBE-10 (10-pack). Also as one side of the BBE/KVL bi-plate.
Medium: Beef extract and gelatin digest base with 20% oxbile equivalent, esculin, ferric ammonium citrate, gentamicin, hemin 10 mg/L, vitamin K1 1 mg/L. Initial pH 7.5.
Type: Selective and differential. Bacteroides fragilis group; black to brown esculin reaction.
Shelf life: 4 months from manufacture. 28-day minimum guaranteed on arrival.
Storage: 2 to 8°C. Ships at room temperature.
Packaging: Individually sealed oxygen-impermeable pouch.
User QC: Listed as exempt under CLSI M22-A3. Lot QC performed by Oxyrase.
Regulatory: For in vitro diagnostic use. Manufactured in Mansfield, Ohio under ISO 9001:2015.
When to use it
The Bacteroides fragilis group is the most common and most antibiotic-resistant anaerobic isolate in clinical practice, and BBE is the fastest route to a presumptive call. A colony on BBE with a black to brown halo at 48 hours is bile-resistant and esculin-positive, which in an anaerobic culture points to the B. fragilis group before any identification system is run. That matters for intra-abdominal, pelvic, and bloodstream infections where empiric coverage decisions are waiting on the lab.
BBE is a selective plate and should never be the only plate. Pair it with OxyPRAS Plus® Brucella for the non-selective baseline and OxyPRAS Plus® KVL for the other gram-negative anaerobes, or use the OxyPRAS Plus® BBE/KVL Bi-Plate to get both selective media in one plate position.
Why PRAS manufacturing matters
Anaerobic media that is poured and packaged in air accumulates oxidation products before it ever reaches your bench. Those products inhibit the most oxygen-sensitive anaerobes, and the effect is invisible: the plate looks fine and simply reports no growth.
OxyPRAS Plus® plates are reduced with the Oxyrase® Enzyme System before sterilization and held in a reduced state through storage and use. In our PRAS vs. non-PRAS comparison, 8 of 30 non-PRAS Brucella plates inoculated with Porphyromonas levii grew nothing at all, while 0 of 30 OxyPRAS Plus® plates failed. OxyPRAS Plus® plates also tolerate up to 2 hours of ambient oxygen exposure during setup without inhibitory oxidation, which gives the bench flexibility to batch work and to use automated streaking platforms.
Read the full data in The Plate That Reports Nothing and the oxygen exposure white paper.
Formulation
Approximate composition per liter of deionized water. Initial pH 7.5 (+0.2 / -0.3). Production lots may be adjusted to offset raw material variance in order to meet performance criteria.
| Component | Amount |
| Beef extract | 11.0 g |
| Enzymatic digest of gelatin | 34.5 g |
| Oxbile | 2.0 g |
| Esculin | 1.0 g |
| Ferric ammonium citrate | 0.5 g |
| Agar | 15.0 g |
| Hemin | 10.0 mg |
| Vitamin K1 | 1.0 mg |
| Gentamicin | 2.0 mL |
| Sodium bisulfite | 0.1 g |
| Oxyrase® Enzyme System | proprietary |
Oxbile and gentamicin together inhibit most gram-negative facultatives and bile-sensitive anaerobes. Esculin hydrolysis by the B. fragilis group releases esculetin, which reacts with ferric ammonium citrate to blacken the medium. Hemin supports the pigmenting Bacteroides group.
Quality control
Samples of every lot are tested to Oxyrase specifications incorporating CLSI M22-A3. The following results are confirmed before release:
| Organism | ATCC | Expected result |
| Bacteroides fragilis | 25285 | Growth; black to brown coloration |
| Prevotella melaninogenica | 25845 | Inhibition (bile) |
| Escherichia coli | 25922 | Inhibition (gentamicin) |
Uninoculated medium is pale yellow with no surface imperfections. Read within 2 to 3 days. BBE agar is listed as exempt from user quality control under CLSI M22-A3; each laboratory should still establish its own QC program in line with its accreditation requirements, and the organisms above are recommended if you choose to test.
Directions for use
- Allow plates to reach room temperature before use.
- Remove the plate from the pouch.
- Check for contamination, oxidation or discoloration, and the expiration date.
- Inoculate and streak using standard technique.
- Invert and incubate at 35 to 37°C in an anaerobic bag, jar, or chamber.
- Include an anaerobic indicator such as OxyBlue™ to confirm anaerobiosis.
- Read plates after 2 to 3 days.
Anaerobic incubation is still required. PRAS manufacturing protects the medium before and during setup; it does not replace the anaerobic atmosphere during incubation.
Storage, shelf life and guarantee
Plates ship at room temperature and should be stored at 2 to 8°C on receipt. Expiration is 4 months from date of manufacture; the actual date is printed on each plate. Oxyrase guarantees at least 28 days of shelf life from the ship date, and longer dating can be arranged when you order. If OxyPRAS Plus® BBE Agar plates arrive short-dated, contaminated, or oxidized, or fail when used as directed, we refund the purchase price. Contact us with the lot number printed on the plate.
Limitations
- As a selective medium it supports only select organisms. Colony types require additional identification.
- B. vulgatus and B. ovatus may not hydrolyze esculin.
- Other organisms that can grow on BBE include Fusobacterium mortiferum, F. varium, gentamicin-resistant Enterobacteriaceae, enterococci, pseudomonads, staphylococci, and yeast. Confirm isolates.
- The Oxyrase® Enzyme System contains a penicillin-binding protein that may interfere with penicillin and some related antibiotics. Do not use these plates for susceptibility testing.
- Contains material of animal origin. Source animals are documented free of BSE/TSE.
Frequently asked questions
What does a black colony on BBE mean?
Growth in the presence of 20% bile plus esculin hydrolysis. In an anaerobic culture that is presumptive for the Bacteroides fragilis group. Confirm with Gram stain, aerotolerance, and an identification method.
Why is the plate yellow instead of red?
BBE has no blood. The pale yellow base makes the black to brown esculin reaction easy to read.
Can gram-positive organisms grow on BBE?
Some can, including enterococci and staphylococci, and yeast will grow. They do not blacken the medium the same way, but a Gram stain settles it.
Do I need to reduce the plates before inoculating?
No. OxyPRAS Plus® plates are reduced during manufacturing and stay reduced in the sealed pouch. Open, inoculate, and incubate.
Does my lab have to run QC on each lot?
BBE agar is on the CLSI M22-A3 list of media exempt from user QC. Each lot is tested by Oxyrase before release. Your accreditation program may still ask you to document receipt and inspection.
Is it available through my distributor?
Yes, through Fisher Scientific and Cardinal Health, or direct from Oxyrase. Ask us about volume pricing for standing orders.