新疆边境地区蜱携带梨形虫种类的分子鉴定

为了调查新疆边境地区梨形虫在当地蜱中的携带情况,对采集于2019年4月份和5月份的新疆边境地区共25个县(市)的蜱进行形态学鉴定,提取DNA,利用梨形虫套式引物进行扩增并测序,并采用IQ-Tree软件的ML法构建不同地理株的进化关系。结果显示,采集到的1516只蜱包括4个属9个种,分别为森林革蜱(Dermacentor silvarum)、草原革蜱(D.nuttalli)、胫距革蜱(D.pavlovskyi)、边缘革蜱(D.marginatus)、亚洲璃眼蜱(Hyalomma asiaticum)、麻点璃眼蜱(H.rufipes)、小亚璃眼蜱(H.anatolicum)、血红扇头蜱(Rhipicephalus sanguineus)和刻点血蜱(Haemaphysalis punctate);对上述蜱种携带梨形虫种类的分子检测结果显示,共检出3种泰勒虫和6种巴贝斯虫,分别为绵羊泰勒虫(Theileria ovis)、马泰勒虫(T.equi)、泰勒虫未定种(Theileria sp.)、驽巴贝斯虫(Babesia caballi)、粗糙巴贝斯虫(B.crassa)、隐藏巴贝斯虫(B.occultans)、犬巴贝斯虫(B.canis canis)、莫氏巴贝斯虫(B.motasi)及巴贝斯虫未定种(Babesia sp.)。结果表明,蜱中梨形虫的平均携带率为27.77%,且新疆边境不同地区的蜱梨形虫的携带率不同。研究结果为梨形虫病的进一步防控以及相关措施的制定提供了依据。

新疆北部地区蜱传嗜吞噬细胞无浆体病原学检测与分子遗传进化分析

为调查我国新疆北部地区蜱及牛、羊体内蜱传播性嗜吞噬细胞无浆体(Anaplasma phagocytophilum)病原的流行情况,收集了新疆北部地区13个县(市)的蜱虫样品及血液样品(蜱虫样品609只,牛血液样品670份,羊血液样品631份),提取基因组DNA,PCR检测后挑选阳性样品测序(1/3),分析其感染状况及病原分子遗传特征。结果显示,蜱虫和血液样品中共检测出183份A.phagocytophilum感染阳性,牛、羊和蜱虫感染率分别为10.0%(67/670)、9.5%(60/631)和8.2%(50/609),样品总体感染率为9.3%(177/1910)。此次获得的新疆北部地区A.phagocytophilum 16S rRNA和MSP 4基因序列遗传进化分析显示,该区牛、羊和蜱体内检测到的病原基因阳性片段与GenBank已公布的中亚、中欧地区病原基因序列同源性为96.7%~99.5%,进化树分析显示与中亚、中欧多国A.phagocytophilum基因序列聚为一支。结果可为新疆北部地区蜱与蜱传播性嗜吞噬细胞无浆体病的防控提供理论依据。

新疆部分地区蜱传斑点热立克次体的分子流行病学研究

【目的】调查新疆地区斑点热群立克次体(spotted fever group rickettsia,SFGR)在蜱虫中的感染情况及其分布.【方法】2018年4~5月,采用人工布旗法对新疆地区10个县(市)的游离蜱和寄生于家畜体表的蜱虫进行采集并鉴定.对采集的蜱虫提取基因组,利用SFGR特异引物对提取的基因组进行PCR扩增及测序分析,用MEGA 6.0软件构建分子系统进化树.【结果】共采集蜱虫2 079只,经鉴定分析,采集的蜱种包括革蜱属、璃眼蜱属和扇头蜱属3属的7个种.扩增得到了包括拉欧蒂立克次体(Rickettsia raoultii)、斯洛伐克立克次体(Rickettsia slovaca)等在内的4种已知SFGR和2株未定种.对其阳性率进行统计结果表明,不同地区的蜱虫阳性率为40%~80%,平均阳性率为51.5%;不同蜱种间的感染率为1.1%~80%.【结论】通过对新疆地区SFGR病原的流行病学调查表明,被检地区SFGR病原阳性率较高,存在2种病原交叉感染现象,且扩增到的病原多属我国少见的人兽共患病病原.

PCR结合核酸斑点杂交检测猪伪狂犬病毒

本研究基于猪伪狂犬病毒(Porcine pseudorabies virus,PRV)gE基因,建立了一种PCR结合核酸斑点杂交检测方法来鉴别野毒株和疫苗株,并利用这一方法对山东省部分地区的猪临床病料中PRV进行了检测。结果显示,建立的PCR结合核酸斑点杂交检测方法只与PRV野毒株反应,而与PRV gE基因缺失疫苗、猪瘟病毒、猪流行性腹泻病毒、猪繁殖与呼吸综合征病毒以及猪圆环病毒2型不反应。PCR结合核酸斑点杂交方法在53份病料中检出PRV阳性病料5份,阳性率为9.43%,高于单纯PCR的检出率(7.55%)。结果表明,本研究建立的PCR结合斑点杂交的方法特异性强,灵敏度高,适合PRV野毒的检测以及流行病学调查,可应用于PRV的鉴别诊断和净化。

RELATIONSHIP BETWEEN THE EXPRESSIONS OF LMP1 AND ECADHERIN/β-CATENIN IN NASOPHARYNGEAL CARCINOMA

Objective:To compare the expression of Epstein-Barr virus encoded LMP1 and E-cadherin/β-catenin in primary and metastatic nasopharyngeal carcinoma(NPC)for the purpose of understanding their relationship.Methods:Twenty-two pairs of biopsies taken from the nasopharynx and cervical lymph node(s)of the same patient with nasopharyngeal carcinoma were collected.The expression of LMP1,E-cadherin andβ-catenin was observed on immunostained slides using LSAB method.Results:The expression rate of LMP1 in the 22 metastatic tumors(86.36%,19/22)was significantly higher than that in the 22 primary growths(68.18%,15/22),P<0.05.The mean expression percentages of E-cadherin andβ-catenin in metastatic tumors(50.11%±22.53%and 66.36±21.05%,respectively)were significantly lower than those in primary growths(71.52±24.34%and 79.40%±15.05%,respectively),P<0.05.There was a positive correlation between the expressions of E-cadherin andβ-catenin either in primary growths or metastatic tumors.Conclusion:The LMP1 is more likely to be expressed in metastatic neoplastic cells of NPC than in primary carcinoma cells,and on the contrary the expression of E-cadherin/β-catenin in metastatic cells was decreased.Accordingly,the LMP1 might have the ability to downregulate the expression of E-cadherin/β-catenin,resulting in enhancement of the invasive capacity of metastatic NPC cells.

Expression of peroxisome proliferator-activated receptor γ,E-cadherin and matrix metalloproteinases-2 in gastric carcinoma and lymph node metastases

Background Peroxisome proliferator activated receptor γ （PPARγ） is a ligand-activated transcription factor. Activation of PPARγ has recently been demonstrated to inhibit various tumor cells growth, progression and metastasis. E-cadherin-mediated cell adhesion system is now considered to be an “invasion suppressor system” in cancer tissues. Matrix metalloproteinases-2 （MMP-2） is a prerequisite for metastasizing tumor cells. However their correlation is still unknown in gastric carcinoma. The aim of this study was to assess the expression of PPAR7, E-cadherin, MMP-2 and their correlation in gastric carcinoma and metastases. Methods Gastric carcinoma tissues and their corresponding lymph nodes with metastases and the adjacent non-tumor tissues were obtained from 54 patients with gastric cancer who underwent gastrectomy. Expression of PPARγ, E-cadherin and MMP-2 was assessed by immunohistochemical staining. Results The nuclear expression level of PPARγ in neoplastic cells was significantly lower than that in the normal controls （P〈0.001）, with the expression of PPARγ being weaker in primary tumors compared with that in metastases. In all neoplastic cells, E-cadherin was expressed with abnormal patterns （cytoplasm pattern, cytoplasm and membrane pattern or absent）, compared with normal cells where E-cadherin was expressed with a normal pattern （membrane pattern）. Compared with the normal tissues, the expression level of E-cadherin decreased in primary tumors and further decreased in metastases （P〈0.001）. Membrane staining of MMP-2 was detected in the foveolar epithelia of normal gastric mucosa, whereas predominant cytoplasm staining of MMP-2 was found in malignant tissues. The expression of MMP-2 was stronger in metastatic tissues than in primary tumors. In neoplastic foci the expression of PPARγ was negatively correlated with MMP-2 expression （P〈0.05）. However, there was no correlation between E-cadherin and PPARγ or MM P-2 expression. Conclusions Down-regulation of PPARγ and E-cadherin and up-regulation of MMP-2 in neoplastic foci might be helpful to gastric carcinogenesis and metastases. An inverse relationship between PPARγ and MMP-2 in human gastric carcinoma suggests that PPARγ might modulate MMP-2 expression and affect gastric cancer metastases.