Seroepidemiological study on Coxiella burnetii and associated risk factors in ruminants at Kurdistan Province,west of Iran

Q fever is zoonotic disease caused by Coxiella burnetii. Ruminants are the main reservoir of this pathogen, which is often asymptomatic but lead to abortion. This study aims to survey the seroprevalence and risk factors of this zoonose among ruminants in Kurdistan province, the west of Iran. 480 blood samples were collected from ruminants including sheep, goats and cows, each 160 samples, in the age groups of <1, ≥1−3, >3−5 year with and without the history of abortion in two groups border and non-border cities in Kurdistan province. Serums were tested by use of indirect ELISA to determine specific antibodies against C. burnetii. The results indicate the seroprevalence of 46.6 % for Q fever. Seroprevalence in sheep, goats and cows were 28.58 % (n = 64), 45.53 % (n = 102) and 25.89 % (n = 58), respectively. Seroprevalence is significantly higher in animals with abortion than in those without such history (P < 0.05). The seroprevalence in the border cities has been significantly higher than other geographical areas (P < 0.05). Seroprevalence had no significant correlation with animal age (P> 0.05). This study is the first seroepidemiological study done on Q fever in ruminants of Kurdistan province, Iran. The results indicate the high seroprevalence of Coxiella burnetii in the area under the study. Therefore, doing an epidemiologically study aimed at isolating C. brunetii in the human population of Kurdistan province is recommended, so that the epidemiological aspect of this pathogen in the people of Kurdistan province be clarified and subsequently disease control and prevention programs be applied.     

商品化猪丹毒疫苗分类及特点

文章介绍了5种商品化猪丹毒疫苗的种类、毒株组成、抗原含量及相应免疫程序,为了解各种类型的猪丹毒商品化疫苗提供参考。     

1株H1N1亚型猪流感病毒的全基因组特征及其对小鼠的致病性

旨在了解河南省猪流感病毒的流行情况及其遗传进化和基因组特征。2018年4月，从河南省某一出现疑似流感症状猪群中采集鼻拭子样品150份用于分离病毒，对分离病毒的全基因组进行序列测定和分析。同时感染6周龄BALB/c小鼠，研究其对小鼠的致病性。结果显示，获得1株H1N1亚型病毒[命名为A/swine/Henan/NY20/2018（H1N1）]。遗传进化表明，其HA和NA基因属于欧亚类禽H1N1分支，PB2、PB1、PA、NP和M基因属于2009甲型H1N1分支，NS基因属于经典H1N1分支。HA蛋白的裂解位点序列为PSIQSR↓GL，具有低致病性流感病毒的分子特征，在小鼠肺和鼻甲有效复制并能引起肺组织病理学变化。本研究分离到1株3源重排H1N1亚型病毒，对小鼠呈现一定致病力，提示应进一步加强对SIV的监测。     

2018年中国部分地区猪瘟病毒2.1d亚型新流行株的基因组特征分析

为了解中国猪瘟病毒（classical swine fever virus，CSFV）的分子流行病学及遗传变异情况，本研究应用RT-PCR方法对2018年采集自河南、河北、山东、黑龙江和辽宁5个省份的350份疑似CSFV感染的病料进行E2和NS5B基因扩增，并对PCR产物进行测序和序列分析。结果显示，350份样品中21份为CSFV阳性，共获得14株CSFV的E2基因序列和7株CSFV的部分NS5B基因序列。E2全基因、NS5B部分基因序列分析表明，21份阳性样品均属于近年来在中国流行的CSFV 2.1d亚型，且新发现的2.1d亚型CSFV与中国较早2.1d亚型CSFV毒株间同源性差异不大，新发现的2.1d亚型CSFV分离株在E2基因的6个氨基酸（R³¹、S³⁴、W¹⁸²、K²⁰⁵、K³⁰³、A³³¹）上具有相同的分子特征，E2蛋白中15个位点上的半胱氨酸均未发生变异。韩国2.1d亚型CSFV在E2蛋白上具有3个独特的氨基酸（N⁹⁷、K¹⁵⁹、R²⁰⁵）特征，并且发现了韩国毒株YC11WB可能作为2.1b和2.1d亚型CSFV过渡毒株的证据，流行于中国和韩国的2.1d亚型CSFV可能分别来自于本国早期2.1b亚型CSFV的衍化。本研究证实，2018年中国及周边国家CSFV较为活跃，且流行毒株依然以2.1d亚型为主，为中国科学防控CSFV提供了依据。     

猪弓形虫病诊断与防治

猪弓形虫病是由刚地弓形虫感染引发的一种血液原虫病,该种疾病属于人畜共患病和典型的免疫性疾病,可以在多种牲畜群体中寄生。猪群一旦受到弓形虫感染,病情会快速传播,蔓延防控不及时,还会造成整个猪群全部发病,死亡率有时高达60%以上,是危害生猪养殖产业的常发病和高发病。因此,需要加强流行病学调查,在疾病进入流行高发期前,采取针对性措施防控,提高防控效果,降低发病率,保障养殖安全。该文探讨猪弓形虫病的流行病学、临床症状、病理变化、诊断方法和防治措施。     

非洲猪瘟疫情对生猪产业链上市公司市场价值的影响研究

[目的] 研究旨在应用实证方法分析非洲猪瘟疫情对生猪产业链上市公司市场价值造成的影响,进而得出疫情对生猪产业链上养殖、屠宰、加工、消费等环节利益相关者收益的影响。[方法]采用事件研究法,选取涉及生猪产业链上市公司,按主营业务统计为肉制品加工、养殖、饲料和兽药4种类型的32家相关上市公司,通过设计指标对生猪产业链上市公司股票异常收益率波动进行计算和检验。[结果]研究结果表明：非洲猪瘟疫情事件对生猪养殖行业的影响最大；对兽药行业的影响周期最长；肉制品加工行业的影响程度和周期仅次于兽药行业,对饲料行业的影响最小。[结论] “非洲猪瘟”事件对猪产业链上的饲料、养殖、肉制品加工、兽药类上市公司市场价值存在显著的负面影响。     

Insights into African swine fever virus immunoevasion strategies

African swine fever(ASF) is an acute and highly contagious disease that causes severe economic losses to the swine industry. ASF is caused by infection of African swine fever virus(ASFV) in domestic pigs, leading to almost 100% mortality. However, no effective vaccines and pharmacologic treatment against ASF are available. ASF poses a severe threat to the swine industry and the economy. Here we summarize potential virus-host cell interaction mechanisms involving the suppression of innate and adaptive immune responses to ASFV entry and infection. These mechanisms include modulation of apoptosis, inhibition of inflammatory responses, reduction of IFN production, inhibition of autophagy, and suppression of MHC-I expression. Insights into immunoevasion strategies by ASFV may shed light on the development of vaccines, as well as preventive and therapeutic drugs.     

Tulathromycin enhances humoral but not cellular immune response in pigs vaccinated against swine influenza

The effect of a standard, single dose therapy with tulathromycin was investigated on the postvaccinal humoral and cellular immune response in pigs vaccinated against swine influenza. Forty‐five pigs, divided into 3 groups, were used (control not vaccinated (C, n = 15), control vaccinated (CV, n = 15), and experimentally received tulathromycin (TUL, n = 15)). For vaccination of pigs, an inactivated, commercial vaccine was used. Pigs from TUL group received single dose of tulathromycin intramuscularly, at the recommended dose (2.5 mg/kg body weight). Pigs from TUL and CV groups were vaccinated at 8 and 10 weeks of age. The specific humoral and cellular immune response against swine influenza virus (SIV) was evaluated. The results of present study showed that humoral postvaccinal response after vaccination against SIV can be modulated by treatment with tulathromycin. In pigs from TUL group, the significantly higher titers of anti‐SIV‐specific antibodies were observed 4 and 6 weeks after booster dose of vaccine. Simultaneously, T‐cell‐mediated immune response against SIV was not affected by tulathromycin. Our recent study confirmed the importance of defining the modulatory activity of tulathromycin because of its influence on the immune response to vaccines. Since the antibodies against hemagglutinin are crucial for the protection against SIV, the present observations should prompt further studies on the practical significance of recent results in terms of clinical implications (postvaccinal protection) in the field conditions.     

African Horse Sickness Fever in Vaccinated Horses: Short Communication

Our investigation has shown that multiple vaccinations with inactivated African horse sickness (AHS) vaccines containing all 9 serotypes and produced at the Central Veterinary Research Laboratory in Dubai, UAE, protect horses from AHS. However, the immunization did not prevent African horse sickness fever (AHSF) in approximately 10% of the vaccinated horses despite high enzyme-linked immunosorbent assay and virus neutralizing antibodies. African horse sickness fever is a very mild form of AHS with similar clinical signs. From all 6 horses which had developed AHSF, no virus was isolated from EDTA blood withdrawn during the acute phase of infection. Despite high neutralizing antibodies, serotype 9 was detected by polymerase chain reaction in 4 of them. All 6 horses recovered within 72 hours, after they developed mild clinical signs of AHS.     

microRNA-124-3p调控H1N1亚型猪流感病毒致小鼠肺损伤的研究

为研究microRNA-124-3p（miR-124-3p）对H1N1亚型猪流感病毒（swine influenza virus，SIV）感染小鼠所致肺损伤的调控作用，本试验构建miR-124-3p腺病毒表达载体，通过小鼠尾部静脉注射法构建miR-124-3p差异表达小鼠模型，试验分3组：过表达组、抑制组和对照组。48 h后，各组小鼠鼻腔接种H1N1亚型SIV，每只10⁵ EID₅₀（50 μL）。连续观察14 d，计算小鼠平均体重变化率、观察病理切片并测定相关炎症因子IL-1β、TNF-α和IL-6 mRNA相对表达量。结果显示，已成功将pre-miR序列及其sponge序列插入腺病毒的穿梭质粒，并将其共转染293A细胞。实时荧光定量PCR检测证实，与对照组相比，过表达组和抑制组小鼠黑色素瘤细胞miR-124-3p表达水平分别极显著升高（P<0.01）和显著降低（P<0.05），表明成功构建腺病毒表达载体。过表达组、抑制组和对照组小鼠体重变化率分别为－5.5%、－12.4%和－8.6%。抑制组和对照组均可见肺泡壁增厚，其间有多量淋巴细胞浸润，部分肺泡内出现纤维蛋白渗出，且抑制组病理变化更为严重，肺泡中还有大量的红细胞浸润；而过表达组仅有少量的淋巴细胞浸润，肺脏组织较正常。与对照组相比，过表达组检测的炎症因子IL-1β、TNF-α和IL-6 mRNA表达水平均显著降低（P<0.05）；抑制组炎症相关炎症因子mRNA表达水平均显著升高（P<0.05）。本试验结果表明，miR-124-3p对H1N1亚型SIV感染小鼠所致的肺脏炎症因子的表达具有抑制作用，同时能减轻肺脏病理损伤。