Geobacillus stearothermophilus Spore Suspension

Growth (after 3 to 3.5 hours / 65 ° C): passes test
Colour change to yellow (after 3 to 3.5 hours / 65 ° C): conforms
Growth test (Test agar for the residue test acc. to KUNDRAT): passes test
Growth test (1 week/refrigerator): passes test
Growth promotion test performed with the following antibiotic testplates:
Gentamicin 10 µg; Gentamicin 30 µg; Penicilin 10 IE; Streptomicin 10 µg;
Incubation: 3 - 3.5 hrs. 65 °C.
Reference: Test agar for the residue test acc. to KUNDRAT.
Number of viable spores G. stearothermophilus ATCC 7953: 5E+07 - 5E+08 CFU/ml
Incubation: 24 - 48 hrs. 65 °C aerobic.
Reference: Tryptic soy agar.
Microbiological purity: passes test
Microbiological purity verified with Blood-agar and Sabouraud-4% dextrose agar with chloramphenicol.
Incubation: minimum 72 hrs. 35 °C aerobic.

The Geobacillus stearothermophilus spore suspension is used in a routine qualitative procedure to detect antimicrobial residues such as antibiotics, sulfonamides and other chemotherapeutics in meat and other foodstuffs of animal origin. It is used in conjunction with the test agar for performing the antibiotics sulfonamide residue test according to KUNDRAT (1.10662).

Detection of antimicrobial residues in meat and other foodstuffs of animal origin is based on agar diffusion, using spores of Geobacillus stearothermophilus ATCC 7953 (sporulation optimized) as test organisms. Antibiotic and sulfonamide residues inhibit the growth of the test organism, which is indicated by the formation of inhibition zones. These inhibition zones remain purple in color whilst the rest of the nutrient medium turns yellow. Cleaning agents, disinfectants and preservatives do not influence the test.