Objective To identify antimicrobial susceptibilities of community-acquired Staphylococcus aureus infections and the risk factors of severe infections.Methods Clinical data of 184 cases of community-acquired Staphylococcus aureus infections collected from 4 hospitals in Ningbo during May 2008 and May 2013 were reviewed.Microbial sensitivity test and virulence genes ( pvl and tst) detection were performed in clinical isolates, and SCCmec genotyping was performed in methicillin-resistant Staphylococcus aureus ( MRSA) strains.Binary logistic regression analysis was used to identify the risk factors for severe infections.Results Among 184 cases of community-acquired Staphylococcus aureus infections, 39 ( 21.20%) were severe cases. Staphylococcus aureus strains were highly resistant to penicillin, erythromycin and clindamycin, but more than 75% strains were sensitive to oxacillin, aminoglycosides, quinolones, rifampicin and vancomycin.Logistic regression analysis showed that advanced age (OR=1.024, 95%CI:1.005-1.043, P<0.05), malignant tumor (OR=15.288, 95%CI:1.609-145.229, P<0.05) , autoimmune diseases or long-term hormone therapy ( OR=12.102, 95%CI:2.082-70.338, P <0.01 ) were risk factors for severe community-acquired Staphylococcus aureus infections. Conclusions Strains isolated from the patients with community-acquired Staphylococcus aureus infections in Ningbo are usually sensitive to oxacillin, aminoglycosides, quinolones, rifampicin and vancomycin, which may be recommended for clinical use.Elder patients and those with malignant tumor, autoimmune diseases or long-term hormone therapy are more likely to develop severe Staphylococcus aureus infections.

Objective To explore the influence of integrin redistribution on hepatoma cell alignment and migration and the influence of cytoskeleton reassembly on integrin redistribution by the method of mechanical loading unloading and fibronection(FN) coating. Method By using immuneofluescence staining, cofocal laser scanning microscopy and quantitative morphological analysis, integrin distribution change and crtoskeleton assembly adjustment were observed and the deformation of cell movement was tested and analyzed quantitatively. Results (1) cells with different forms have different integrin expressions and distribution features. The β1 integrin expression for spreading cells was higher than that for round (nonspreading) cells. For spreading cells, the strongest staining was found towards the attachment surface. While for round (nonspreading) cells, the integrin staining on the free surface towards medium was stronger than that towards the attachment surface. (2) After 5 hours of mechanical stretch, the β1 integrin expression for both spreading and round cells increased, and distribution peaks towards the attachment surface broadened. At 1 hour after unloading, the β1 integrin expression decreased and the distribution of integrin staining showed the tendency of dispersion, especially for round cells. (3) After coating the substrates with FN, the β1 integrin expression increased. The integrin staining for either spreading or round cells was more towards the attachment surface to reduce the migration of hepatoma cells. 4) After 5 hours of mechanical stretch, 60% of cells showed their orientation of major axes distributed between 70°～110° towards the stretching direction, and the cytoskeleton aligned vertically to the stretching direction. Cytoskeletons were found significantly depolymerized at 1 hour of unloading. Conclusions The change of integrin distribution is affected by cytoskeleton aligned and the number of ligand. The distribution feature of the whole integrin expression on the surface of individual round cells is related to their stronger invasion and metastasis capability.