Blood Culture System From Oxoid
The Oxoid blood culture system is used to test blood samples for microbial activity. Samples are first collected from patients, taking care to use sterile equipment. These samples are then inoculated into blood culture bottles before being mixed with the medium used for the culture.
The medium used in the Oxoid blood culture system is designed to provide a hospitable environment for the growth of aerobic, anaerobic and micro-aerophilic microorganisms and to create pressure in the sealed culture bottle while these organisms grow.
Positive pressure is detected with a growth indicator device which is added to the culture bottle once the blood sample has been inoculated into the bottle. Positive pressure is used as an indicator of microbial activity in the Oxoid blood culture system, since it indicates that the blood/broth mixture is being displaced by microbial growth. Once the mixture rises above the level of the bottle’s green locking sleeve, a positive result is indicated.
The system includes 20 (40 with Plus version) culture bottles and growth indicator de vices and five incubation trays as well as the medium.
The typical formulation of the medium is pH 7 and contains:
- 10 g/L Tryptone Soya Broth
- 10 g/L Gelatin peptone
- 5 g/L Yeast extract
- 5 g/L Meat extract
- 8 g/L Sodium chloride
- 2 g/L Potassium nitrate
- 1 g/L Glucose
- 1 g/L L-arginine
- 1 g/L Sodium pyruvate
- 1g/L Gelatin
- .5 g/L Sodium thioglycollate
- .4 g/L Cysteine HCl
- .4 g/L Sodium bicarbonate
- .3 g/L Phosphate buffer
- .3 g/L Sodium polyanethol sulphonate
- .2 g/L Dithiothreitol
- .01 g/L Adenine sulphate
- .01 g/L Sodium succinate
- .008 g/L Ammonium chloride
- .008 g/L Magnesium sulphate
- .005 g/L Menadione
Sodium polyanethol sulphonate (3%) is added the Oxoid blood culture system to inhibit coagulation, neutralize the bactericidal effects of human blood and prevent phagocytosis. It also partially inactivates antibiotics includcing streptomycin, kanamycin, gentamicin and polymixin B and may inhibit some strains of ofPeptostreptococcus anaerobius, Neisseria meningitidis and Neisseria gonorrhoeae. For this reason, gelatin is included in the formula for the media to neutralize this effect.
To find out about Oxoid's blood culture system products, please click on an icon on this page.
Date added: 2015-05-25 10:47:03