鸡白痢沙门菌感染产蛋期蛋鸡的致病性分析  

Pathogenicity analysis of Salmonella pullorum infection in laying hens

作　　者：周雯 王彦红[1,2] 鞠辉明 ZHOU Wen;WANG Yanhong;JU Huiming(College of Veterinary Medicine,Yangzhou University,Yangzhou,Jiangsu 225009,China;Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses,Yangzhou University,Yangzhou,Jiangsu 225009,China)

机构地区：[1]扬州大学兽医学院,江苏扬州225009 [2]江苏高校动物重要疫病与人兽共患病防控协同创新中心,江苏扬州225009

出　　处：《中国兽医学报》2024年第3期484-490,共7页Chinese Journal of Veterinary Science

基　　金：江苏高校优势学科建设工程资助项目(PAPD)。

摘　　要：为了解鸡白痢沙门菌感染产蛋期蛋鸡致病特点,采集2022年2-11月感染产蛋期蛋鸡的肝脏等组织开展研究。对病鸡的肝脏、脾脏进行细菌分离,对分离菌株进行多重PCR鉴定和血清型检测;取病变的肝脏等组织制备病理切片以观察其病理变化;通过qRT-PCR分析肝脏、脾脏组织中鸡白痢沙门菌毒力基因和细胞因子mRNA的表达水平。结果表明,从送检的蛋鸡中分离出18株细菌,在麦康凯培养基上生长无色小菌落,多重PCR鉴定和血清型为鸡白痢沙门菌;病理切片可见心肌、肝脏及肺脏炎性细胞群浸润和细胞坏死;qRT-PCR检测显示感染鸡白痢沙门菌的病鸡诱导生物被膜相关基因(CsgB、RpoS、bcsA和PagC)、SPI-1基因(HilA、InvA、PrgH和SipC)和SPI-2基因(SteE、RcsC、SseL和SpiC)等毒力基因的表达水平上调;感染产蛋鸡的肝脏中IL-1β、IL-6、IL-4和IL-13的表达水平上调,IL-18和IFN-γ表达水平降低;脾脏中IL-6高度表达,IL-1β和IL-18表达水平显著降低。本研究中感染病鸡组织中鸡白痢沙门菌使生物被膜、SPI-1、SPI-2相关毒力基因和TH2分泌的细胞因子表达上调,表明鸡白痢沙门菌感染宿主时在细胞内和细胞外大量增殖和扩散,引起病理变化和自身免疫反应。To understand the pathogenic characteristics of Salmonella pullorum-infected laying hens,liver and other tissues of infected hens from February to November 2022 were collected for the study.The livers of diseased chickens were isolated,and the isolates were identified by multiplex PCR and serotyped;pathological sections were prepared from the diseased livers and other tissues to observe the pathological changes;the expression levels of virulence genes and cytokine mRNA of Salmonella pullorum in liver and spleen tissues were analyzed by qRT-PCR.The results showed 18 strains of bacteria were isolated from the submited laying hens,and small colorless colonies grown on MacConkey medium,they were identified by multiplex PCR and serolyped as Salmonella fowl dysentery;pathological sections showed infiltration of inflammatory cell clusters and cell necrosis in the myocardium,liver,and lungs.qRT-PCR assay showing upregulation of the expression levels of virulence genes such as biofilm-related genes(CsgB,RpoS,bcsA and PagC),SPI-1 genes(HilA,InvA,PrgH and SipC)and SPI-2 genes(SteE,RcsC,SseL and SpiC)induced in sick chickens infected with Salmonella pullorum;the expression levels of IL-1β,IL-6,IL-4 and IL-13 were up-regulated and the expression levels of IL-18 and IFN-γwere decreased in the liver of infected laying hens;IL-6 was highly expressed and IL-1βand IL-18 expression levels were significantly decreased in the spleen.In this study,the expression of biofilm-related genes,SPI-1,SPI-2-related virulence genes and TH2-secreted cytokines was up-regulated in the tissues of infected chickens,indicating that Salmonella pullorum invaded the host in different ways intracellularly and extracellularly,leading to its massive proliferation and dissemination,causing pathological changes and autoimmune responses.

关 键 词：鸡白痢沙门菌 蛋鸡 产蛋期 毒力基因 细胞因子 

分 类 号：S858.31[农业科学—临床兽医学]