摘要
目的通过环磷酰胺注射建立免疫抑制大鼠模型,探究免疫抑制大鼠肺部菌群变化,为探究免疫低下患者肺部感染菌群的结构与来源提供依据。方法选用140~160 g雄性SD大鼠,随机分为对照组(A)和免疫抑制组(B),每组10只。每日按60 mg/kg体质量给予免疫抑制组大鼠腹腔注射浓度为10 mg/ml环磷酰胺溶液,对照组大鼠仅腹腔注射等体积生理盐水溶剂。连续注射3 d后,分别对两组大鼠心脏采血,测血细胞计数,取肺组织进行16s rDNA高通量测序和生物信息学分析。结果与A组相比,B组大鼠中性粒细胞、淋巴细胞、单核细胞等白细胞数量明显降低。A组各门水平上优势菌门为厚壁菌门(Firmicutes)、变形菌门(Proteobacteria)、拟杆菌门(Bacteroidetes)、放线杆菌门(Actinobacteria);在属水平上优势菌属为乳酸杆菌(Lactobacillus)、拟杆菌(Bacteroides)以及未定型瘤胃球菌(unidentifiedRuminococcaceae)等。B组在门和属水平上与A组无明显差异。对样本进行Alpha多样性指数组间差异分析,ACE、Chao1、Shannon、Simpson四个指数间差异不显著(pACE=0.569,pChao1=0.599,pShannon=0.370,pSimpson=0.460)。PCoA分析结果表明,两组各样品分布相似度较高。结论通过高剂量环磷酰胺腹腔注射,成功制作免疫抑制大鼠模型。阐明免疫抑制大鼠和正常大鼠肺部菌群结构,并发现两者在丰度和多样性上差异并不显著。这提示,免疫低下患者肺部感染的致病菌可能并非源自肺部机会致病菌的异常增殖,而是来源于外界环境吸入。
Objective To provide data for exploration of the source of pulmonary infection in immunocompromised patients by studying the changes in pulmonary microflora in immunosuppressive rats.Methods Male SD rats(140-160 g)were randomly divided into the control group(A,n=10)and immunosuppressive group(B,n=10).Rats in the immunosuppressive group were given intraperitoneal injection of cyclophosphamide at the concentration of 10 mg/ml per day according to the body mass of 60 mg/kg,while the rats in the control group were injected intraperitoneally with the same volume of normal saline solvent alone.After 3 days of continuous injection,blood samples were collected from the hearts of the two groups for blood cell count,and lung tissues were taken for 16 s rDNA high-throughput sequencing and bioinformatics analysis.Results The number of neutrophils,lymphocytes and monocytes in group B was significantly smaller than that of group A.In group A,the dominant phyla were Firmicutes,Proteobacteria,Bacteroidetes and Actinobacteria at the family leval.At the genus level,the dominant bacteria were Lactobacillus,Bacteroides,and unidentifiedRuminococcaceae.There was no significant difference in the dominat phylum and genus levels between the two groups.The difference analysis of the Alpha Diversity index showed that there was no significant difference between ACE,Chao1,Shannon,and Simpson(pACE=0.569,pChaol=0.599,pShannon=0.370,and pSimpson=0.460).The results of PCoA analysis showed a high similarity of sample distribution between group A and group B.Conclusion A immunosuppressive rat model has been established by intraperitoneal injection of high-dose cyclophosphamide.The structure of pulmonary microflora in immunosuppressive rats and normal rats has been clarified,and there is no significant difference in abundance and diversity between them,suggestsing that the pathogens of pulmonary infection in immunocompromised patients are not caused by the amplification of opportunistic pathogens in the lungs,but probably by inhalation from the external environment.
作者
董辉伟
陈郑珊
金敏
谭蓉
孙栋良
杨栋
李君文
DONG Hui⁃wei;CHEN Zheng⁃shan;JIN Min;TAN Rong;SUN Dong⁃liang;YANG Dong;LI Jun⁃wen(Institute of Environmental and Operational Medicine,Academy of Military Medical Sciences,Academy of Military Sciences,Tianjin 300050,China;Troops 65316 of PLA,Wafangdian,Liaoning 116300,China)
出处
《军事医学》
CAS
北大核心
2020年第11期811-814,820,共5页
Military Medical Sciences
基金
国家自然基金重点项目(41831287)
国家自然科学基金面上项目(81673122)
天津市自然科学基金重点项目(19JCZDJC39900)
环境医学与作业医学研究所青年创新团队培育计划基金项目(2019CTXD02)
