共同感染对白色念珠菌感染状态的影响研究  

Co-infection with EHEC and C.albicans in vitro enhances invasion and tissue damage of enterocytes induced by C.albicans

作　　者：杨卫明[1] 吴春荣[1] 许群欢[1] 唐建国[1] 周艳君[2] 

机构地区：[1]复旦大学附属上海市第五人民医院创伤急救危重病医学中心,上海200240 [2]中国农业科学院上海兽医研究所,上海200241

出　　处：《中华急诊医学杂志》2016年第4期423-428,共6页Chinese Journal of Emergency Medicine

基　　金：上海市卫生和计划生育委员会科研课题面上项目（201540136）;闵行区卫生和计划生育委员会科研课题（2013MW12）

摘　　要：目的研究致病大肠杆菌和白色念珠菌共同感染对白色念珠菌侵袭力和破坏性的影响。方法通过构建白色念珠菌和致病大肠杆菌共同感染离体肠上皮细胞（ Caco-2）的模型来研究共同感染对白色念珠菌感染状态的影响。通过倒置显微镜观察感染早期发生侵袭的白色念珠菌特征；通过测定乳酸脱氢酶（ LDH）活性评估上皮细胞被破坏程度；通过实时荧光定量PCR （ qRT-PCR）检测感染相关基因（ ALS3、 PLB1和SAP4）表达调控情况。采用SAS软件包进行数据统计分析。采用方差分析比较进行多组之间的比较，对于组间有差异的数据进一步采用Bonferroni法进行两两比较。以P＜0.05为差异具有统计学意义。结果显微镜观察发现共同感染组比单纯白色念珠菌感染组在感染早期更容易发生上皮细胞侵袭，侵袭的白色念珠菌呈簇状分布； LDH活性检测显示同时共同感染组（组3）最高（与组1、组2、组4、组5比较 F 值分别为14.48、5.48、11.74、3.45， P＜0.05），致病大肠杆菌继发白色念珠菌感染组（组5）和单纯致病大肠杆菌感染组（组2）之间差异无统计学意义（F＝2.03， P＝0.54），白色念珠菌继发致病大肠杆菌感染组（组4）和单纯白色念珠菌感染组（组1）之间差异无统计学意义（F＝2.74， P＝0.11），组5、组2LDH活性值大于组1、组4（P＜0.05）；同时伴随白色念珠菌致病相关基因（PLB1和SAP4）上调， PLB1基因表达组3高于组1（ P ＝0.0143）， SAP4表达组3、组5高于组1（ P 值分别为0.0272、0.0018）。结论致病大肠杆菌和白色念珠菌共同感染增强了白色念珠菌的侵袭力和破坏性，并且增强的程度与两种菌的发病顺序和共存时间长短有关。Objective To investigate, in vitro, the co-infection of Caco-2 cells （ epithelial cells of intestinal mucosa） with Candida albicans and Enterohemorrhagic escherichia coli （ EHEC） .Methods The ability of both species to invade the Caco-2 cells was evaluated by inverted microscopy.Damage to Caco-2 cells was evaluated by measuring lactate dehydrogenase （ LDH ） activity. C. albicans virulence gene expression （ ALS3, PLB1 and SAP4 ） was evaluated by quantitative real-time polymerase chain reaction （ qRT-PCR） .Results Compared to simple infections with C.albicans alone, a co-infection invaded Caco-2 cells more rapidly, and C.albicans tended to proliferate more easily presenting in cluster shape of distribution.In addition, the LDH activity in the co-infection group （group 3） was the highest compared to groups 1, 2, 4 and 5, （F values of 14.48, 5.48, 11.74 and 3.45 respectively;all P 〈0.05）;There was no significant difference in LDH activity found between the secondary fungous infection group （ group 5） and the EHEC infection group （group 2） （F=2.03, P=0.54） or between the secondary bacterial infection group （group 4） and the Candida albicans infection group （group 1） （F=2.74, P=0.11）.The LDH activities in groups 2 and 5 were significantly higher than that in groups 1 and 4 （ all P 〈0.05 ） .In addition, an up-regulation of toxicity-related genes （ PLB1 and SAP4 ） were detected.The expression of PLB1 was higher in group 3 than that in group 1 （ P=0.014 3 ） and SAP4 was higher in groups 3 and 5 than that in group 1 （P=0.027 2, P=0.001 8, respectively）.Conclusions Using Caco-2 cells for an infection model, this study demonstrated that co-infecting in vitro enterocytes with C.albicans and EHEC enhanced the invasiveness and tissue damaging effects of C.albicans.

关 键 词：致病大肠杆菌 白色念珠菌 共同感染 侵袭力 破坏性 倒置显微镜 乳酸脱氢酶 实时荧光定量PCR 

分 类 号：R519.3[医药卫生—内科学]