【 Principle 】

Tryptone provides the necessary carbon, nitrogen, vitamins, and growth factors for bacterial growth; High concentration sodium chloride forms a system with high osmotic pressure, inhibiting the growth of bacteria that are not tolerant to high salt; Lactose is a fermentable carbon source; Phosphates serve as buffering agents, providing a relatively stable acid-base buffering system for bacterial cells; Sodium laurel sulfate inhibits the growth of non coliform bacteria; Vancomycin inhibits Gram positive bacteria.

Main components

Composed of tryptone, sodium chloride, lactose, potassium dihydrogen sulfate, dipotassium dihydrogen phosphate, sodium dodecyl sulfate, vancomycin, and distilled water.

Storage conditions and expiration date

Storage conditions: This product should be stored in a dark environment at 2-8 ℃.

Validity period: The unopened original packaging has a validity period of 6 months.

This product is a disposable product.

Testing of infant formula food: According to GB 4789.40, trace amounts of Cronobacter were enriched by triple inhibition of 44 ℃+cinnamyl sulfate+vancomycin.

Risk screening of dairy products: screening raw materials and semi-finished products such as fresh milk and milk powder base materials, and controlling source contamination of Enterobacter sakazakii.

Production environment monitoring: Detect the coating samples of milk powder production line pipelines, drying equipment, operation platforms, etc., and investigate environmental pollution sources.

Pre culture of positive samples：transfer of turbid tubes to chromogenic agar to obtain single colonies for biochemical and serum typing.

Disinfection process validation: Residual bacteria were detected in the sample after neutralization, and the killing effect of high-temperature cleaning and chemical disinfection was evaluated.

Laboratory quality control: Use standard bacterial strains as positive controls to verify the antibacterial and high-temperature screening performance of vancomycin.

Suspected poisoning diagnosis: Simultaneous enrichment of the child's feces and remaining milk powder to assist in the diagnosis of Enterobacter sakazakii infection.

Cronobacter sakazakii

Biological characteristics: Gram negative flagellar bacteria, facultative anaerobic, spore like tolerant structure, heat-resistant and osmotic pressure resistant; Can tolerate high temperatures of 44 ℃, cinnamyl sulfate, and vancomycin; Fermented lactose; Tolerant to high salt, high temperature, low concentration of surfactants and vancomycin are the advantageous proliferating bacteria in this culture medium.

MLST Vm culture reaction: After 24 hours of cultivation at 44 ℃, the broth became uniformly turbid, and the culture medium had a light yellow background without discoloration or precipitation; Vancomycin and laurel sulfate suppressed all gram-positive bacteria, with only Cronobacter sakazakii reproducing massively.

Pathogenicity: High risk pathogenic bacteria in infant formula milk powder can cause neonatal meningitis, sepsis, and necrotizing enteritis.