Fraser-Bouillon, halbkonzentriert
According to § 64 LFGB
| Shorthand symbol: | HFAB |
| Item number: | 60-1034 |
| Format: | Tube, 9ml |
| Colour: | Yellowish, half-transparent |
| Storage conditions: | Dry, closed at 15-22°C |
| Shelf-life: | 4 Weeks |
| pH: | 7.2 ± 0.2 at 25°C |
The Fraser broth (semi-concentrated) is used for the selective enrichment of Listeria spp. from food (§ 64 LFGB) and environmental materials.
| in g per 1l Nutrient medium | |
|---|---|
| Meat peptone | 5 |
| Casein peptone | 5 |
| Meat extract | 5 |
| Yeast extract | 5 |
| Sodium chloride | 20 |
| Sodium hydrogen phosphate | 12 |
| Potassium dihydrogen phosphate | 1.35 |
| Aesculin | 1 |
| Lithium chloride | 3 |
| Ammonium Iron (III)-citrate | 0,5 |
| Acriflavine-Hydrochloride | 0.0125 |
| Nalidixic acid | 0.01 |
| *Adjusted as required to meet performance standards |
The microbial performance test is carried out in conformity with the requirements of DIN EN ISO 11133.
Productivity
Incubation conditions: 24 ± 2 hours at 30 ± 1 °C; Inoculum concentration: ≤ 100 CFU
| Organism | Test strain | Specification | Colony morphology | |
|---|---|---|---|---|
| Listeria monocytogenes 4b + Escherichia coli + Enterococcus faecalis | ATCC 13932 / WDCM 00021 + ATCC 8739 / WDCM 00012 + ATCC 19433 / WDCM 00009 | > 10 colones of Palcam-Agar | Grey green and black colonies with black background (Palcam) | |
| Listeria monocytogenes 1/2a + Escherichia coli + Enterococcus faecalis | ATCC 35152 / WDCM 00109 + ATCC 8739 / WDCM 00012 + ATCC 19433 / WDCM 00009 | > 10 colonies of Palcam-Agar | Grey green and black colonies with black background (Palcam) |
Selectivity
Incubation conditions: 48 ± 2 Stunden bei 37 ± 1 °C; Inoculum concentration: 10.000 - 1.000.000 CFU
| Organismus | Test strain | Specification | Colony morphology | |
|---|---|---|---|---|
| Escherichia coli | ATCC 8739 / WDCM 00012 | Complete inhibition | - | |
| Enterococcus faecalis | ATCC 19433 / WDCM 00009 | < 100 Colonies of TSA | - |
Microbial Contamination
Incubation conditions: 5 – 7 days at 20 – 25 °C and 5 – 7 days at 30 – 35 °C
| Specification |
|---|
| No microbial contamination |