鹅蛋源波茨坦沙门菌的分离鉴定及致病性分析  

Isolation,identification and pathogenicity analysis of Salmonella Potsdam from goose egg

作　　者：赵毅 王俊 贾艳[1] 樊国良 周利娟 禹海杰[1] ZHAO Yi;WANG Jun;JIA Yan;FAN Guo-liang;ZHOU Li-juan;YU Hai-jie(Jiaxing Vocational and Technical College,Jiaxing 314036,China;Wangdian Town Government Service Center,Jiaxing 314011,China;Haiyan Animal Husbandry and Veterinary Service Center Service Center,Jiaxing 314300,China)

机构地区：[1]嘉兴职业技术学院,浙江嘉兴314036 [2]嘉兴市王店镇政务服务中心,浙江嘉兴314011 [3]海盐县畜牧兽医服务中心,浙江嘉兴314300

出　　处：《中国预防兽医学报》2024年第4期350-356,373,共8页Chinese Journal of Preventive Veterinary Medicine

基　　金：嘉兴市公益性研究计划项目(2022AY30008);嘉兴市公益性研究计划项目(2021AY10050);嘉兴市科技特派员专项(K2022C013)。

摘　　要：为鉴定鹅蛋表面污染菌并分析其生物学特性和致病性,本研究使用无菌棉签擦拭从农贸市场采集的鹅蛋表面,利用肠杆菌科鉴别培养基(XLD)、革兰氏染色、PCR方法和MLST分型鉴定分离株;通过K-B琼脂扩散法检测分离株的药物敏感性;通过细菌计数法分析分离株对各环境的耐受性(紫外线、75%乙醇、不同浓度NaCl);采用PCR方法检测分离株的毒力基因;将分离株分别以10^(9)cfu、10^(8)cfu和10^(7)cfu剂量经皮下注射感染3日龄雏鹅和雏鸭,连续观察8 d,记录各动物的发病症状和死亡情况,分别以10^(9)cfu和10^(8)cfu剂量口服感染3日龄雏鹅和雏鸭,每天称重记录并统计它们的体重变化;分别于感染后不同时间剖杀动物,无菌采集各组动物不同脏器,采用平板计数法测定各组动物肝脏和脾脏的载菌量。结果显示,分离株在XLD培养基中呈现黑色带金属光泽菌落,革兰氏染色为红色中等大小杆状菌,PCR扩增出典型沙门菌目的条带,MLST分型为ST2039,表明分离株为波茨坦沙门菌,命名为JX202305。药物敏感性试验结果显示分离株对多西环素、复方新诺明等大部分抗生素敏感,对头孢曲松、头孢噻肟和萘啶酸耐药。环境压力耐受性测试结果显示,分离株经紫外线照射5 min、10 min、15 min和20 min,细菌数量由9×10^(8)cfu/mL分别下降至3 000 cfu/mL、100 cfu/mL、40 cfu/mL和0,均与对照组差异极显著(P<0.001),表明分离株对紫外线耐受能力差;75%乙醇作用1 min即导致细菌存活率下降至0,表明75%乙醇对该分离株具有较强的杀灭效果;与对照组相比,5%、10%、15%、20%Na Cl处理细菌30 min和60 min对细菌存活均无显著影响(P>0.05),25%NaCl处理30 min和60 min才导致细菌存活率分别下降至38%和10%(P<0.05),表明分离株对NaCl耐受性较强。皮下注射感染试验结果显示,分别以10^(9)cfu、10^(8)cfu和10^(7)cfu剂量感染时,雏鹅的死亡率分别为90%、60%和20%,雏鸭的死亡率�To identify the contaminated bacteria on the surface of goose eggs and analyze their biological characteristics and pathogenicity,the isolates were identified using Enterobacteriaceae identification medium,Gram staining,PCR method,and MLST typing,and the drug susceptibility was measured by agar diffusion method,and analyzing the tolerance of isolated strain to various environments using bacterial counting method(UV,75%ethanol,different concentrations of NaCl).The isolated strain virulence genes were detected by PCR method;Subcutaneously inject the isolated strain at doses of 10^(9)cfu,10^(8)cfu,and 10^(7)cfu to infect 3-day-old goslings and ducks.The observation lasted for 8 days,and the symptoms and mortality were recorded.3-day-old goslings and ducklings were orally infected with 10^(9)cfu and 10^(8)cfu doses to analyze weight changes and bacterial load in organs.The results revealed that the isolated strain showed a black metallic luster colony in XLD medium,and a red medium-sized rod shape after Gram staining.The typical Salmonella target band was amplified by PCR,and the MLST typing was ST2039.The isolate was identified as Salmonella Potsdam,named JX202305.The drug susceptibility results showed that the isolate was sensitive to most antibiotics such as doxycycline,compound sulfamethoxazole,while insensitive to ceftriaxone,cefotaxime and nalidixic acid.The environmental stress tolerance test results showed that the number of the isolate decreased from 9×10^(8)cfu/mL to 3000cfu/mL,100cfu/mL,40cfu/mL and 0 after UV irradiation for 5min,10min,15min and 20min,respectively.The difference is extremely significant compared to the control group(P<0.001),indicating that the isolated strains have low UV tolerance.Treatment with 75%ethanol for 1min led to a decrease in bacterial survival rate to 0,which indicated that 75%ethanol has a strong killing effect on the isolated strain.Compared to the control group,separate treatment with 5%,10%,15%,and 20%NaCl concentrations for 30min and 60min had no significant impact on b

关 键 词：鹅蛋 波茨坦沙门菌 分离鉴定 致病性 

分 类 号：S852.61[农业科学—基础兽医学]