Mycoplasma hyopneumoniae and its role in the Porcine Respiratory Disease Complex 猪肺炎支原体及其在猪呼吸系统综合疾病中的作用 Dr. Maria Pieters 玛丽亚 皮特斯博士
Outline 纲要 Porcine Respiratory Disease Complex (PRDC) 猪呼吸道疾病综合征 (PRDC) M. hyopenumoniae infection in pigs 猪肺炎支原体感染 Summary 总结
What is PRDC? 什么是 PRDC? Swine polymicrobial respiratory disease 多种微生物引起的猪呼吸系统疾病 Main players: 主要角色 : PRRSV 蓝耳病病毒 SIV 猪流感病毒 PCV2 圆环病毒 2 型 Pasteurella multocida 多杀性巴氏杆菌 M. hyopneumoniae 猪肺炎支原体
What is the cost of respiratory disease in pigs? 猪呼吸系统疾病成本是多少? SIV, PRRS, 和朱肺炎支原体对生产性能和经济的影响 与基线比较每头猪损失 Haden et al., 2012
M. hyopneumoniae infection in pigs 猪肺炎支原体感染 and its role in PRDC: 及其在猪呼吸系统综 合征中的作用 When does it occur? 它什么时候发生? What does it do to the pig? 它对猪如何影响? For how long it persists? 持续多久? How is it controlled? 如何控制?
Epidemiology of M. hyopneumoniae 猪肺炎支原体的流行病学
Risk factors associated with Mycoplasma hyopneumoniae prevalence at weaning 在断奶时与猪肺炎支原体发病相关的危险因素 Fomites/Vectors 污染物 / 载体 Environment 环境 Mother 母体 Piglet 仔猪 Management 管理 Birth 出生 Weaning 断奶 Lactation period 哺乳期
Prevalence at weaning varies AMONG herds 断奶时发病率在不同猪群中的不同 不同欧盟国家用鼻拭子在 3 周龄仔猪中肺炎支原体检出率 Villarreal et al., 2010
Prevalence at weaning varies WITHIN herds 断奶时猪的患病率在同一猪群中不同 断奶时猪肺炎支原体定植 ( 开始发病 ) Fano et al., 2007
Sow parity influences shedding 母猪胎次影响散 毒 Parity 胎次 Tested piglets 被测试的仔猪 Positive piglets 阳性仔猪 Prevalence at weaning 断奶患病率 Young 幼猪 176 59 32.76a Intermediate 中期 132 28 23.04b Old 老猪 120 24 20.4b Fano et al., 2007
Prevalence of M. hyopneumoniae by PCR by farm (sows and piglets) 按场通过 PCR 检测的猪肺炎支原体的发病率 ( 母猪和仔猪 ) Serum prevalence for M. hyopenumonaie (piglets; Idexx ELISA) 猪肺炎支原体的血清检测 ( 小猪 ; IDEXX ELISA 法 ) Pieters et al., 2014
Regression of percent M. hyopneumoniae PCR positive dams and percent M. hyopneumoniae PCR positive piglets 母猪猪肺炎支原体 PCR 阳性百分比和仔猪肺炎支原体 PCR 阳性回归分析 Pieters et al., 2014
Piglet probability of being positive to M. hyopneumoniae PCR given the dam M. hyopneumoniae PCR status 由于母体猪肺炎支原体情况小猪肺炎支原体 PCR 阳性的概率 Pieters et al., 2014
M. hyopneumoniae colonization at weaning 断奶时猪肺炎支原体定植 Fomites 污染物 Management 管理 Weaning Environment 环境 Piglet 仔猪 Sow 母猪
Important to recognize that 重要的是要认识到... Colonization 定植 Infection 感染 Clinical expression 临床表达
Enzootic pneumonia 地方性肺炎
Pathogenesis 发病机制
Predisposition to secondary respiratory infection 易患继发呼吸道感染
M. hyopneumoniae infection 猪肺炎支原体感染 Phases of Infection 感染阶段 dpi Acute 急性 Chronic 慢性 0 ~ 70 254 Clinical signs 临床症状 Experimental infection 实验感染 Clearance 清除 Pieters et al., 2008
M. hyopneumoniae persistence not affected by vaccination or medication 猪肺炎支原体的持久性不会受到疫苗或药物的影响 Mycoplasma hyopneumoniae detection by PCR in bronchial swabs from all experimental groups at the three sampling times 所有试验组三个采样时间支气管拭子都用 PCR 检测到猪肺炎支原体 The use of M. hyopneumoniae vaccination alone or in combination with treatment with medication did not result in an earlier elimination of the M. hyopneumoniae carrier status 单独免疫或与药物治疗相结合不能提早清除猪肺炎支原体携带状态 Painter et al., 2012
M. hyopneumoniae infection can be controlled 猪肺炎支原体感染可以被控制 Management practices 管理办法 Animal flow 动物流动 Ventilation 通风 Room separation 分离 Antibacterial drugs 抗菌药物 Lack of cell wall 缺乏细胞壁 Effect on persistence? 影响持久性?
M. hyopneumoniae infection can be controlled 猪肺炎支原体感染可以被控制 Vaccination 接种疫苗 Eradication 根除 Partial protection 部分保护 Does not prevent colonization 并不阻止定植 Partial depopulation 部分减群 Medication Vaccination ~ 药物治疗 免疫
寄养对猪肺炎支原体母体免疫转到仔猪身上的作用
M. hyopneumoniae antibodies in piglets 仔猪的猪肺炎支原体抗体 母抗转移 免疫 x 非免疫 免疫 x 免疫 24 hrs after suckling 哺乳 24 小时后
M. hyopneumoniae antibodies in piglets 仔猪的猪肺炎支原体抗体 母抗转移 免疫 x 非免疫 免疫 x 免疫 非免疫 x 免疫 24 hrs after suckling 哺乳 24 小时后
Delayed-type Hypersensitivity (DTH) responses in cross-fostered piglets (4 days of age) 寄养仔猪 (4 日龄 ) 中的延迟型超敏反应 (DTH) 0 6 12 20 0 6 12 20 0 6 12 20 (hrs) 免疫 x 对照非免疫 x 对照免疫 x 免疫免疫 x 非免疫非免疫 x 免疫
M. hyopneumoniae immunity can be affected by management practices 管理措施影响猪对猪肺炎支原体的免疫能力 Immune cells and antibodies are transferred in a different manner under cross-fostering conditions 在寄养条件下免疫细胞和抗体传递方式不同 M. hyopneumoniae specific antibodies are absorbed in less than 12hrs after suckling, regardless of the source 不论其来源如何, 猪肺炎支原体特异性抗体在哺乳 12 小时后被吸收 Piglets that suckled from their vaccinated mothers for at least 12 hrs showed a cellular response 仔猪从它们接种疫苗的母亲哺乳至少 12 小时, 显示有细胞反应
What can be expected from vaccination? 我们对免疫的期望是什么? Incomplete protection 不完整的保护 Does not prevent colonization 并不阻止定植 Decreased bacterial load 减少细菌量 Decreased infection at herd level 在猪群中减少感染 Effects are apparent after several months of vaccine application 免疫几个月后的效果显而易见
M. hyopneumoniae and antibiotics 猪肺炎支原体和抗生素 Modified from Sketchymedicine.com
General considerations about antimicrobials 关于抗菌药物的一般考虑 More flexible ways for usage vs. vaccines 与疫苗相比有更灵活的使用方式 Target more than one pathogen 针对一个以上的病原体 Flexible administration and delivery: 灵活的用药方式 : Water 水 Feed 饲料 Resistance reported Not a major issue 有耐药性报告 - 不是主要问题 Residues 残留
Summary 总结 M. hyopneumoniae plays a critical role in the development of PRDC 猪肺炎支原体在 PRDC 发生过程中起关键作用 Concurrent infections and management factors influence disease outcome 并发感染和管理因素影响发病结果 Control measures directed at one pathogen will/can have an effect on others 针对一种病原体的控制措施, 将 / 能对其它病原有作用 Still a big concern and cause of economic losses for the swine industry 对养猪业仍然是一个大问题并导致经济损失
Thanks! 谢谢!