Association study of invasiveness of Staphylococcus aureus with different types of SCCmecs

Objective To investigate the relationship between invasiveness of Staphylococcus aureus and types of SCCmecs and to provide scientific data for prevention and control of Staphylococcus aureus infection.Methods Human type Ⅱ alveolar epithelial cells were attacked by MSSA and five types of SCCmecs MRSA.After two hours,the bacteria inside the cells were released by cracking cells with Triton-X 100.They were cultured and quantified through counting cloning form unit.The ratio of bacteria inside the cells to original bacteria indicated the invasiveness of Staphylococcus aureus.Results ①There was no statistical significance in invasiveness between MSSA and MRSA strains.②The invasion of SCCmec Ⅱ was higher than that of SCCmec Ⅲ,Ⅳ and MSSA(P =0.021,0.005,0.016).Conclusions The invasiveness of Staphylococcus aureus is associated with types of SCCmecs,but no completely relationship exists between the invasiveness and the amount of drug-tolerance gene. Key words: Staphylococcus aureus;  SCCmec;  Invasiveness;  Drug resistance gene;  Human type Ⅱ alveolar epithelial cells