急性腹泻患者奇异变形杆菌分离鉴定及其生物学特性  

Isolation and Biological Characteristics of Proteus mirabilis from Patients with Acute Diarrhea

作　　者：蒋小武 艾莎珍 贺志述 朱乐欣 洪亮义 周林华[1] JIANG Xiao-wu;AI Sha-zhen;HE Zhi-shu;ZHU Le-xin;HONG Liang-yi;ZHOU Lin-hua(College of Medicine,Yichun University,Yichun 336000,China)

机构地区：[1]宜春学院医学院,江西宜春336000

出　　处：《宜春学院学报》2023年第3期1-7,共7页Journal of Yichun University

基　　金：国家自然科学基金项目(编号:32060791);江西省大学生创新创业项目(编号:S202010417049)。

摘　　要：目的:对某市医院腹泻门诊收集的一起急性腹泻患者肛拭子样本进行奇异变形杆菌分离鉴定、耐药性与致病作用分析。方法:增菌培养、划线分离,革兰氏染色,镜检观察细菌形态,16S rRNA基因扩增、测序鉴定细菌种类;纸片法进行药物敏感性检测,PCR法筛检毒力基因,结晶紫染色法检测细菌生物被膜形成,小鼠感染试验分析分离株致病力;荧光PCR法分析奇异变形杆菌感染小鼠致不同脏器炎症因子表达水平。结果:成功从腹泻样本中分离获得3株细菌(NB1711、NB1335和NB1336),经菌种鉴定均为奇异变形杆菌。3株细菌对米诺环素、红霉素、多粘菌素等9种药物表现为多重耐药,对头孢唑林、哌拉西林、环丙沙星等敏感。NB1711分离株完整编码8种毒力因子,生物被膜形成能力强,对小鼠致病最高,感染该菌株可显著上调小鼠不同脏器IL-1β、IL-6、TNFα、IFN-γ等炎症因子的表达。结论:奇异变形杆菌感染是引发此次急性腹泻的主要病因,细菌分离株NB1711耐药谱广、毒力强、可形成致密生物被膜,感染小鼠介导形成炎症反应。本研究为进一步探究奇异变形杆菌感染机制及临床用药提供科学依据。Objective:To investigate the etiology of anal swab samples collected from patients in an acute diarrhea event from one city hospital.Clinical antibiotics sensitivity and pathogenicity of the bacterial isolates were also analyzed.Methods:After microbial enrichment,bacteria purification and identification were performed with plate streaking,morphological observation and 16S rRNA gene sequencing.The isolated clones were subjected to further antibiotics sensitivity test by K-B method.Virulence factors and biofilm formation were screened and tested by the method of PCR and crystal violet staining,respectively.The pathogenic effect and pro-inflammatory reactions were evaluated and determined in mice with Proteus mirabilis(PM)infection.Results:Three strains,named as NB1711,NB1335 and NB1336,were isolated and identified as Proteus mirabilis.All PM isolates were found to be resistant to multiple antibiotics such as minocycline,erythromycin and polymyxin and sensitive to cefazolin,piperacillin and ciprofloxacin.NB1711,which encoded eight typical virulence genes,was a highly pathogenic strain with the capability for biofilm formation.The mRNA levels of inflammatory factors of IL-1β,IL-6,TNFαand IFN-γwere significantly up-regulated in mice organs with sub-lethal infection of NB1711.Conclusion:Proteus mirabilis infeciton maybe the major etiology leading to acute diarrhea in patients.The isolate of NB1711 was a highly pathogenic strain with a relative broad antibiotics resistance spectrum.This strain infection could activate a pro-inflammatory response in mice.The results of this study provide scientific basis for guiding patients’clinical medication and pathogenesis investigation for Proteus mirabilis.

关 键 词：奇异变形杆菌 分离鉴定 致病性 耐药性 炎症反应 

分 类 号：R378[医药卫生—病原生物学]