Obiective To investigate the molecular characteristics of heteroresistant vancomycinintermediate Staphylococcus aureus(hVISA)in China and analyze the differences of the molecular characteristics between hVISA and VSSA(vancomycin-susceptible Staphylococcus aureus)isolates.Methods A total of 3 15 non-repetitive MBSA were collected from the national surveillance program in China in 2007.The isolates of hVISA were confirmed by modified population analysis profile-area under the curve(PAP-AUC).The genotypes of agr and SCCmec were determined by multiplex PCR,and spa typing was performed bv PCR and DNA sequencing.The pvl gene was detected bv PCR Results The prevalence of hVISA was 9.5%(30/315).Among 315 MRSA,SCCmec Ⅲ was the most popular type,which was found in 234 isolates(234/315,74.3%),followed by SCCmec Ⅱ,which was identified in 56 isolates (56/315,17.8%).The rate of SCCmec Ⅱ in hVISA(46.7%)was significantly hisher than in VSSA (14.7%,X~2=18.93,P＜0.001).The most prevalent agr type among 315 MRSA was agr 1 accounting for 73.6%(232/315).The agr 2 accounted for 18.7%(59/315),and agr 3 and agr 4 were very rare in clinical isolates.It was different in agr types between the two groups.The rate of agr 2 in hVISA(53.4%)was higher than in VSSA(15.1%).X~2 value was 26.08 and P value was less than 0.001 through X~2 test.There was a statistical significance in the result.There were 4 spa types in hVISA isolates,including t002 (13 isolates),t037(9 isolates),t030(6 isolates),and 1548(2 isolates).The pvl positive MRSA isolates were very low,accounting for 1.6%(5/315).Conclusions The prevalence of hVISA was relatively higher in China.Compared to VSSA,the majority(53.4%)of the hVISA strains were agr 2,which was obviously different from VSSA.hVISA isolates were more diverse by spa typing,

[摘 要] 目的：探究落新妇苷（AST）调节低氧诱导因子-1α（HIF-1α）/血管内皮生长因子（VEGF）轴对乳腺癌细胞增殖、迁移和血管生成拟态（VM）的影响。方法：用不同浓度的AST（0、5、25、50、100、150、200、300 μmol/L）处理乳腺癌细胞MCF-7、MDA-MB-231，采用CKK-8法检测细胞活力。将MCF-7、MDA-MB-231细胞分为对照组、AST低剂量（AST-L）组、AST中剂量（AST-M）、AST高剂量（AST-H）组、AST-H+DMOG（HIF-1α/VEGF通路激活剂）组，EdU法检测AST处理对乳腺癌细胞增殖的影响，流式细胞术检测其对细胞凋亡的影响，Transwell小室实验检测其对细胞迁移、侵袭能力的影响，Matrigel管型形成实验检测其对细胞VM形成的影响，WB法检测对细胞中HIF-1α、VEGF、VE-cadherin、E-cadherin、N-cadherin、MMP-2表达的影响。结果：与0 μmol/L AST相比，5、25、50、100、150、200、300 μmol/L AST处理的细胞活力显著下降，呈剂量依赖性（P<0.05）。与对照组相比，AST-L、AST-M、AST-H组细胞EdU阳性率、细胞迁移数、细胞侵袭数、VM管腔数目、HIF-1α、VEGF、VE-cadherin、N-cadherin、MMP-2表达均显著下降，而细胞凋亡率、E-cadherin蛋白表达显著升高（均P<0.05）；与AST-H组相比，AST-H+DMOG组细胞EdU阳性率、细胞迁移数、细胞侵袭数、VM管腔数目、HIF-1α、VEGF、VE-cadherin、N-cadherin、MMP-2表达均显著升高，而细胞凋亡率、E-cadherin蛋白表达均显著下降（均P<0.05）。结论：AST能抑制乳腺癌细胞增殖、迁移、侵袭和VM形成，促进凋亡，其作用机制可能与抑制HIF-1α/VEGF信号通路有关。