This Cronobacter Biochemical Identification Kit is a comprehensive 11-test system designed for the biochemical confirmation of Cronobacter species (formerly classified as Enterobacter sakazakii). The kit is configured according to the GB 4789.40 standard for the microbiological examination of food, particularly powdered infant formula.
The kit provides all the necessary biochemical media for the presumptive identification and differentiation of Cronobacter from related Enterobacteriaceae. It includes tests for amino acid decarboxylases (lysine, ornithine, arginine), carbohydrate fermentation (sorbitol, rhamnose, sucrose, melibiose, amygdalin), citrate utilization, and oxidase activity.
Each kit contains sufficient materials for 10 complete sets (11 tests × 2 sets/box × 5 boxes). The media are supplied in sealed ampoules for convenience and safety, and sterile liquid paraffin is included for overlaying the decarboxylase broths to create anaerobic conditions.
Intended Use
- Biochemical identification and confirmation of Cronobacter species.
- Microbiological testing of powdered infant formula and dairy products.
- Food safety and hygiene verification according to GB 4789.40.
- Quality control in food and pharmaceutical laboratories.
- Research and educational laboratory applications.
Kit Contents (11 Tests, 2 Sets per Box, 5 Boxes)
- Lysine Decarboxylase Broth: 2 ampoules
- Ornithine Decarboxylase Broth: 2 ampoules
- L-Arginine Dihydrolase Broth: 2 ampoules
- Amino Acid Decarboxylase Control: 1 ampoule
- Simmons Citrate Agar: 2 ampoules
- D-Sorbitol: 2 ampoules
- L-Rhamnose: 2 ampoules
- D-Sucrose: 2 ampoules
- D-Melibiose: 2 ampoules
- Amygdalin: 2 ampoules
- Sterile Liquid Paraffin: 1 ampoule
- Oxidase Test Paper: 1 pack
Results Interpretation (Reference)
| Test | Positive | Negative | Incubation |
|---|---|---|---|
| Oxidase | Blue / blue-purple | No color change | — |
| L-Lysine Decarboxylase | Purple | Yellow | 24 ± 2 h |
| L-Ornithine Decarboxylase | Purple | Yellow | 24 ± 2 h |
| L-Arginine Dihydrolase | Purple | Yellow | 24 ± 2 h |
| Amino Acid Decarboxylase Control | Yellow | Yellow | 24 ± 2 h |
| Simmons Citrate | Blue | Green / yellow | 24 ± 2 h |
| D-Sorbitol | Yellow | Red | 24 ± 2 h |
| L-Rhamnose | Yellow | Red | 24 ± 2 h |
| D-Sucrose | Yellow | Red | 24 ± 2 h |
| D-Melibiose | Yellow | Red | 24 ± 2 h |
| Amygdalin | Yellow | Red | 24 ± 2 h |
Note: For decarboxylase tests, add sterile liquid paraffin overlay after inoculation. Compare the test broth to the control tube. If the test broth turns purple and the control remains yellow, the test is positive. If both remain yellow, the test is negative.
Storage and Shelf Life
- Format: Ampoules in a multi-box kit (11 tests × 2 sets/box × 5 boxes).
- Shelf Life: 1 year from date of manufacture.
- Storage: Store at 2–8°C. Do not freeze.
Q: What is this kit used for?
A: This kit is used for the biochemical identification and confirmation of Cronobacter species (formerly Enterobacter sakazakii) in food and environmental samples according to the GB 4789.40 standard.
Q: What is included in the kit?
A: The kit includes 11 different biochemical tests (decarboxylase broths, sugar fermentation tubes, citrate agar, oxidase test paper), plus sterile liquid paraffin and sealing film. It contains enough material for 10 complete sets.
Q: How do I interpret the decarboxylase tests?
A: After incubation with a paraffin overlay, a positive result is indicated by a purple color in the test broth while the control tube remains yellow. If both tubes remain yellow, the result is negative.
Q: What is the recommended incubation condition?
A: Incubate most tubes at 30 ± 1°C for 24 ± 2 hours. The Simmons Citrate tube should be incubated at 36 ± 1°C.
Q: How should I store the kit?
A: Store the kit at 2–8°C. Do not freeze. The shelf life is 1 year from the date of manufacture.
Q: Is this kit intended for clinical use?
A: No. This kit is intended for laboratory quality control and food safety testing only. It is not intended for clinical diagnosis.
