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Welcome! Welcome!
We're once again back for our weekly (maybe a little longer) article about a product!
This week we're focusing on something new, our own bench reagents. We supply quite a few so there's a lot to cover, in total we have:
- Catalase
- Kovacs reagent
- KOH
- Oxidase strips
- Neisseria PET
- Spot Indole
- Pyrazinamidase test
- Nitrate discs
- Ninhydrin
- Nitrate reagents
- Urease
- Nitrocefin discs
As you can see we have quite a few, so let's get into it!
Catalase 3%
Catalase 3%
CK9830, 5 x 3ml Vials
The Classic test for differentiating staphylococci (positive) from streptococci (negative). This test detects the enzymes catalase and peroxidase, either of which releases oxygen from hydrogen peroxide with subsequent bubbling.
To observe the action of these enzymes, catalase reagent, a dilute solution of hydrogen peroxide is added to a pure bacterial culture. Any immediate observed bubbling is indicative of a positive result, since oxygen is a byproduct of hydrogen peroxide decomposition. This test can also be useful in the differentiation of Gram-positive bacilli.
Catalse 15%
CK9810, 5 x 3ml Vials
The Wadsworth manual recommends 15% hydrogen peroxide for the catalase testing of anaerobes as being more sensitive than 3%. NB. Care is needed when performing catalase tests on colonies growing on blood agar, as the medium itself will give a positive reaction.
Spot Indole
Spot Indole
CK9053, 5 x 3ml Vials
The indole test is valuable in the differentiation of Enterobacteriaceae and also anaerobic genera and species. On media containing tryptophan; metabolism of tryptophane results in the formation of indole, which reacts with p-dimethlyaminocinnamaldehyde, to produce a blue/ green colour.
The test can be done by impregnating the reagent onto a filter paper, and touching a colony, they rubbing it onto the impregnated paper by touching the colony with the swab impregnated with the reagent.
Pyrazinamidase Test
Pyrazinamidase Test
CK4537 28 Tests, CK9801 5 x 3ml Vials
The test for pyrazinamidase (pyz) activity is a useful screening test to distinguish between potentially toxigenic Corynebacteria spp. The following are pzy negative: C. diptheriae, C. ulcerans and C. pseudotuberculosis, whilst other corynebacteria are pyz positive.
The developing reagent CK9801 Ferrous sulphate as a solution has a short shelf-life, to overcome this problem, the reagent is therefore supplied as a pellet in the dropper bottles, to be reconstituted before use.
Oxidase
Oxidase
CK3520 50 Strips
Oxidase is an enzyme produced by some bacteria for electron transport and nitrate metabolism. Detection of this enzyme is performed with freshly grown cultures, where it is more useful in the identification of some species.
All Neisseria species are oxidase positive, and most fermenting Gram-negative rods are oxidase negative, with the exception of some Vibrios, Aermonads, Pasturella and Chromobacteriae.
Most non-fermenting Gram-negative rods are oxidase positive. The test involves smearing a portion of the freshly cultured colony onto a moistened strip and observing. The development of a blue/ black colour within 30 seconds indicates a positive reaction. The test is being carried out using colonies picked from a blood containing medium, using either a plastic or platinum loop, a nichrome loop may generate false positives and should not be used.
Kovacs Reagent
CK9020 5 x 3ml Vials
Kovacs reagent is intended to be used for the detection of tryptophanase production, which can be used as an aid in the differentiation of the Enterobacterales and other genera. The active ingredient of Kovacs reagent, p-dimethlyaminobenzaldehyde, reacts with indole to form a pink/red compound.
Potassium Hydroxide (KOH) 3%
CK9860 5 x 3ml Vials
KOH is intended for use in the differentiation of Gram-positive, and Gram-negative, organism. Being simple and easy to use, while being rapid and inexpensive. KOH can be used in addition to a Gram-stain for primary differentiation of bacterial isolates.
Other Reagents in our Catalogue
For more information on each please contact us via our website, our email or telephone.
- Nitrate Discs - CK9850
- Ninhydrin 3.5% - CK9058
- Nitrate Reagent A - CK9841
- Nitrate Reagent B - CK9842
- Urease (15 Minutes) - CK3650
- Urease/Indole - CK4651
Anaerobe Identification
These reagents are required for first day 'Level one' identification, recommended in the Wadsworth Anaerobic Bacteriology Manual.
- Catalase 15% - CK9810
- KOH 3% - CK9860
Neisseria Detection
Neisseria PET (preformed enzyme test) presumptively identifies N. gonorrhoea, meningitis and Lactamaca in 32 minutes.
- Neisseria PET - CK3025
- Nitrocefin Discs - CK2001
- Oxidase Strips - CK3520
Whilst the use of a single test method, and clinical findings, may be considered sufficient for a presumptive identification, we would advise the use of at least 2 test methods involving different principles (such as biochemical, antigenic or molecular) before issuing a definitive/confirmed identification for Neisseria gonorrhoea (advice from the UKHSA SMI (Chlamydia and Gonorrhoea infection - testing by nucleic amplification tests (NAATs) - Virology, V37, Issue 5, 12.12.24))
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It's a new week, so it's a new BioConnections post! This week we're talking blood culture identification (BCID). BCID is covered mainly by Microbiologics and their QC panels, but you'll never guess what! We supply our own Fastidious Anaerobe Agar (F.A.A) for culturing your positive blood cultures on!
Blood Culture Identification
Complementing this, BioConnections (our own) FAA Agar provides a high-performance medium for the cultivation of fastidious anaerobes, supporting consistent growth and reproducible results. Together, these tools empower laboratories to maintain the highest standards in microbiological testing while enhancing efficiency and patient outcomes.
Microbiologics
The Gram-Negative Blood Culture Control Panel also includes 3 pools containing 3-5 inactivated microorganisms per pool. Kits contain 5 vials of each pool (15 total vials) and feature colour coordinated labels for easy pool identification.
BioConnections
Yes your eyes are working correctly, We offer our own F.A.A agar for you to pour your own plates. These plates have one of the same benefits as CHROMagar dehydrated media (if you think back to last week), it has a super long shelf-life! It comes in either 500g or 2.5kg that can be sent to you!
Our medium also has the option to be made selective with the addition of antibiotic supplements. This is the medium of choice for the routine isolation of clinically significant anaerobes, our medium supports the growth of most fastidious anaerobes. Classical colony formation, odour and fluorescence under UV are diagnostic features on this medium. The choice of peptones and growth factors provide early growth of most organisms whilst the starch has an important role as a de-toxification agent. The medium is often made selective for various groups of anaerobes by the addition of appropriate selective agents.
