[Cloning the Staphylococcus aureus enterotoxin B gene, obtained by polymerase chain reaction, and its expression in Escherichia coli cells]. / Klonirovanie gena énterotoksina B Staphylococcus aureus, poluchennogo metodom polimeraznoi tsepnoi reaktsii, i ego ékspressiia v kletkakh Escherichia coli.

ABSTRACT

To determine the Staphylococcus aureus enterotoxigenicity, we have developed an approach based on polymerase chain reaction (PCR). Using this method several S. aureus strains have been screened for the presence of the enterotoxin B gene. A DNA fragment of the selected strain (FRI 722H) containing enterotoxin B gene has been obtained by the PCR method and cloned in the pUC19 vector. It is shown that enterotoxin B with the leader peptide forms insoluble complexes in E. coli cells, whereas the mature toxin is present in cytoplasmic fraction in a soluble form. The recombinant toxin made up for 1.7% of the total cellular protein in E. coli JM 109 cells.