[Multiple-locus variable number tandem repeat analysis of Staphylococcus aureus in one food poisoning case]

To type Staphylococcus aureus strains from a food poisoning case by MLVA method, detect staphylococcal enterotoxin, and provide lab evidence for molecular epidemiological study and analysis of evolution.

The genomic DNA of 10 stains in the food poisoning case were used as PCR template. Eight pairs of primers were selected from the MLVA database. The PCR method was carried out and the PCR products were analyzed by capillary electrophoresis. The results were analyzed by BioCalculator and compared with the MLVA database. The staphylococcal enterotoxin was detected with colloidal gold method.

The 8 VNTR PCR products have no differernce in the 10 strains, the size of VNTR09_01, VNTR61_01, VNTR61_02, VNTR67_01, VNTR21_01, VNTR24_01, VNTR63_01 and VNTR81_01 are 373, 361, 328, 279, 845, 354, 394 and 658 bp, respectively. The 10 strains belong to the same MLVA type, which is a new MLVA type differnernt from other 3892 strains in MLVA database, the MLVA profile is 15-2-2-2-35-8-2-7. Meanwhile, the 10 strains have the same kind of staphylococcal enterotoxin, the are enterotoxin A and enterotoxin B.

The 10 Staphylococcus aureus strains are of one MLVA type, and have the same characters of staphylococcal enterotoxin. They have high homology.