摩洛哥北部婴儿利什曼原虫MON-1引起犬利什曼病

利什曼原虫是专性细胞内寄生原虫,可引起人体皮肤、粘膜、内脏利什曼病。婴儿利什曼原虫可引起犬内脏利什曼病。犬是婴儿利什曼原虫的重要保虫宿主。在摩洛哥,犬利     

四川省黑水县利什曼原虫家犬感染率的检测

目的 了解四川省黑水县利什曼病流行区家犬的利什曼原虫感染现状,并比较PCR和ELISA检测利什曼原虫无症状感染的效能.方法 2009年5月在犬源型利什曼病疫区四川省黑水县随机选取的无内脏利什曼病现症的家犬,采集静脉血,采用ELISA方法检测血清中利什曼原虫特异性抗体,用两组PCR引物RV1、RV2和K13A、K13B检测血样中利什曼原虫特异DNA,并比较两种检测方法的敏感性.结果 PCR法检测抗凝静脉血阳性检出率为30.47%(32/105),ELISA法检测血清阳性检出率为19.05%(20/105).结论 四川省黑水县存在大量的利什曼原虫无症状感染犬,PCR是检测无症状感染较敏感的方法.     

无症状的内脏利什曼病

以色列及其附近地区是内脏利什曼病的流行区;皮肤利什曼病主要是在其南半部,而内脏利什曼病则存在于加利利地区,用ELISA对加利利东部地区的犬进行利什曼病调查,阳性率为5％;自犬分离的原虫属杜氏利什曼原虫。1991年自加利利西部一病犬分离的原虫经鉴定亦为杜氏利什曼原虫。     

婴儿利什曼原虫KMP-11蛋白基因的克隆与表达以及抗原性分析

在地中海地区,人和犬感染婴儿利什曼原虫可引起内脏利什曼病(VL),且艾滋病患者常易感VL,因此对VL疫苗的研制很有意义,目前主要集中于利什曼原虫膜表面分子的研究。 本文对婴儿利什曼原虫KMP-11蛋白基因组结构、序列及其在寄生虫感染中的抗原性进行研究。根据已发表的杜氏利什曼原     

在伊朗拥有家犬是导致当地人感染婴儿利什曼病的一个危险因素

婴儿利什曼原虫感染引起的内脏利什曼病 (VL) ,是动物源性疾病。通常认为家犬是其主要传播源 ,所以大都采取大规模清除感染犬的措施以控制这种疾病的传播。然而这项措施的实施效果并不明显 ,一个可能的解释是家犬在该病传播中起次要作用 ,而本文提供的研究结果再次无可辩驳地证明 :家犬是人类感染婴儿利什曼原虫的一个最重要的危险因素。本研究在伊朗西北部的内脏利什曼病主要流行区内进行 ,该地仅有感染的儿童表现为内脏利什曼病。在该区 38个村庄内随机抽取 3872名年龄小于 1 0岁的儿童 (占该区儿童总数的 31 % )进行直接血凝法(DAT)检…     

对犬注射疫苗预防巴西利什曼病

犬皮肤利什曼病早在本世纪二十年代已在巴西圣保罗州发现。从七十年代以来,巴西一些地区的流行病学调查结果表明,人和犬都是巴西利什曼原虫的偶然宿主,人的感染程度与犬利什曼病的分布有密切关系。本文采用对犬注射疫苗的方法,试图预防人体皮肤利什曼病和粘膜利什曼病。试验在巴西艾斯比利多桑多州Viana市郊一个巴西利什曼病流行区进行,当地犬的巴西利什曼原虫感染率高达25%。取4月龄幼犬8只,在接种利什曼疫苗之前,先服抗蠕虫药驱虫,再注射抗Parvo病毒、抗钩端螺旋体和抗犬瘟热疫苗免疫,然后用含200     

婴儿利什曼原虫实验感染草原兔尾鼠的进一步观察

给草原兔尾鼠经腹腔接种不同量的婴儿利什曼原虫前鞭毛体,结果表明,不同量的原虫感染对动物体重及肝重没有明显的影响,但脾重则有一定的差异。肝脏原虫负荷随感染虫量的增加而加大,实验结果进一步证明草原兔尾鼠是一种对利什曼原虫非常敏感的实验动物,同时在用级差较小的不同量的原虫接种后,可以显感染程度的差别,这就为利什曼病的免疫学研究提供了良好的动物模型。     

用McAb-AST及骨髓涂片法对四川省汶川县犬感染利什曼原虫的调查研究

作者等用单克隆抗体-抗原斑点试验(McAb-AST)及骨髓穿刺涂片法对汶川县125只犬进行感染利什曼原虫调查,骨髓涂片法查出原虫的阳性犬46只,感染率为36.8％,较之历年来陇南、川北报道的犬感染率为高,不但查明了当地犬感染利什曼原虫的严重性,且为本年在白蛉繁殖季节前消除这些传染源提供了确切依据。为了研究对犬利什曼病的简易、准确的调查方法,我们同时用McAb-AST对该125只犬的血清,检测其循环抗原,结果与骨髓涂片阳性符合率为97.8％,总符合率95.2％,可望取代骨髓涂片法。     

苏丹、肯尼亚、埃塞俄比亚的利什曼原虫分泌因子血清型

苏丹人体利什曼病大多数是杜氏利什曼原虫引起的内脏感染,可出现皮肤和皮肤粘膜损害,虽在某些地区可能有真正的皮肤利什曼病。野生啮齿动物和一些哺乳动物是人内脏利什曼病的储存宿主,以东方白蛉为媒介。在肯尼亚和埃塞俄比亚的人体利什曼病分为内脏利什曼病与皮肤利什曼病两种。内脏利什曼病发生于平原低地区,其病原为杜氏利什曼原虫,东方白蛉和马丁氏白蛉可能是媒介,曾有啮齿动物感染的报告,但是否为该地内脏利什曼病的动物保虫宿主尚属可疑。     

犬利什曼病化疗后的临床、寄生虫学和昆虫学随访

犬是婴儿利什曼原虫的主要保虫宿主。犬感染后有淋巴结肿大,眼、鼻周糠状皮炎,皮毛无光泽和脱落、鼻出血、角膜结膜炎、趾甲弯曲、体重明显下降、肝脾肿大,在许多组织内包括皮肤均可发现原虫。在欧洲的犬利什曼病疫点,50％以上原虫阳性犬无症状,但这类犬和有症状的一样能感染白蛉。本文的目的在于观察病犬经治疗后临床变化及与原虫清除间的关系。     

Diffuse intralobular liver fibrosis in dogs naturally infected with Leishmania (Leishmania) chagasi

The aim of this study was to evaluate the diffuse intralobular fibrosis in dogs naturally infected with Leishmania (Leishmania) chagasi. One hundred five infected animals with positive serologic tests for Leishmania were divided into two clinical groups: 69 symptomatic animals and 36 asymptomatic. Special staining with Gomori, Heidenhain, Silver, and Picrosirius Red was applied to characterize fibrilopoesis. The tissue parasite load was measured by immunohistochemistry and associated histomorphometric analyses. Intralobular fibrosis was observed in all dogs, and more collagen deposition was confirmed in the infected animals than in the controls by these histomorphometric studies. There were significant differences among the distinct clinical groups. In fact, symptomatic dogs showed an increased collagen deposition in the liver compared with asymptomatic ones. A peculiar diffuse intralobular fibrosis, where the collagen fibers encircled small groups of hepatocyte(s), was observed in two cases (1.9%).     

Activity of a paromomycin hydrophilic formulation for topical treatment of infections by Leishmania (Leishmania) amazonensis and Leishmania (Viannia) braziliensis

Studies on in vitro skin permeation and in vivo anti-leishmanial activity in mice experimentally infected with Leishmania (Leishmania) major pointed out to the potential of a new paromomycin (PA) formulation (hydrophilic gel) for treatment of cutaneous leishmaniasis (CL). In this study, the activity of this formulation was evaluated in animals experimentally infected by Leishmania species that prevail in the New World. PA gel activity was compared to antimony treatment, since it is still the first choice treatment to the different clinical forms of leishmaniasis. The topical treatment activity with 10% PA gel in BALB/c mice infected by Leishmania (Leishmania) amazonensis was higher than that observed for parenteral antimony treatment, while the efficacy of these two regimes in hamsters infected by Leishmania (Viannia) braziliensis was similar. These results suggest that this formulation could be suitable for clinical studies and may represent an alternative novel formulation for topical treatment of CL.     

The effect of pentostam and cimetidine on the development of leishmaniasis (Leishmania mexicana amazonensis) and concomitant malaria (Plasmodium yoelii)

BALB/c mice were infected with Leishmania mexicana amazonensis and/or Plasmodium yoelii in order to determine the impact of multiple parasitic infection on the efficacy of chemotherapeutic agents. Uninfected, P. yoelii-infected, L.m. amazonensis-infected, and L.m. amazonensis and P. yoelii-infected mice were inoculated with cimetidine (80 mg kg-1 day-1) or pentostam (200 mg kg-1 day-1) once a day for an initial 20-day period, and once a week thereafter. Leishmania mexicana amazonensis lesion development and P. yoelii parasitaemia were the criteria used to assay disease severity. Mice infected with both P. yoelii and L.m. amazonensis developed more severe disease than did animals infected with either parasite alone. Cimetidine and pentostam each slowed the development of L.m. amazonensis in animals infected with only that parasite and in animals infected with both P. yoelli and L.m. amazonensis. However, mice treated with pentostam developed more severe P. yoelii infections than did control animals, whereas cimetidine significantly reduced P. yoelii parasitaemia in all instances.     

Effect of levamisole on the course of experimental leishmaniasis in guinea-pigs and mice: haematological and immunological findings

The effects of levamisole on the course of Leishmania enriettii infection in guinea-pigs and L. major in mice were investigated. It was demonstrated that levamisole-treated guinea-pigs either did not develop an ulcerative lesion or developed a much smaller lesion than untreated animals. Moreover, metastases which are commonly produced in approximately 50% of animals receiving 2 x 10(6) L. enriettii did not occur in levamisole-treated guinea-pigs. Leishmania enriettii infection usually causes leukopenia and eosinophilia in guinea-pigs approximately two to three weeks after infection. These haematological changes did not occur in animals receiving levamisole. The percentage of rosette T-cells which diminished in the L. enriettii infection was normalized in the group of levamisole-treated and infected guinea-pigs. The severity of Leishmania infection in mice receiving levamisole was lower in comparison to a control group of the animals.     

Chronic interstitial pneumonitis in dogs naturally infected with Leishmania (Leishmania) chagasi: a histopathological and morphometric study

Eighteen mongrel dogs of unknown age and naturally infected with Leishmania (Leishmania) chagasi, were obtained from the City Hall of Belo Horizonte, Brazil. Four dogs were used as control. Lung samples were obtained and immediately fixed in formalin. The histopathological picture of all lung tissue sections was a chronic and diffuse interstitial pneumonitis. The thickened inter-alveolar septa were characterized by the cellular exudate (mostly macrophages, lymphocytes and plasmocytes) associated with collagen deposition. Morphometric analysis showed greater septal thickness in the infected animals than in controls. In fact, the morphometric study of collagen stained with ammoniac silver confirmed a larger deposition of collagen in the infected animals. The parasitologic method was carried out during the study of the lesions on the slides. However, we did not observe any correlation between the histopathologic and morphometric data and the clinical status of the animals. We conclude that the pulmonary lesions observed in all naturally infected dogs were correlated with the disease and that the morphometric method used was satisfactory for the analysis of septal thickness and of increased collagen deposition, confirming the presence of fibrosis.     

Tissue cytokine responses in canine visceral leishmaniasis

To elucidate the local tissue cytokine response of dogs infected with Leishmania chagasi, cytokine mRNA levels were measured in bone marrow aspirates from 27 naturally infected dogs from Brazil and were compared with those from 5 uninfected control animals. Interferon-gamma mRNA accumulation was enhanced in infected dogs and was positively correlated with humoral (IgG1) but not with lymphoproliferative responses to Leishmania antigen in infected dogs. Increased accumulation of mRNA for interleukin (IL)-4, IL-10, and IL-18 was not observed in infected dogs, and mRNA for these cytokines did not correlate with antibody or proliferative responses. However, infected dogs with detectable IL-4 mRNA had significantly more severe symptoms. IL-13 mRNA was not detectable in either control or infected dogs. These data suggest that clinical symptoms are not due to a deficiency in interferon-gamma production. However, in contrast to its role in human visceral leishmaniasis, IL-10 may not play a key immunosuppressive role in dogs.     

Presence of antibodies in the aqueous humour and cerebrospinal fluid during Leishmania infections in dogs. Pathological features at the central nervous system

In the present paper we show that in dogs, naturally infected with Leishmania infantum , the aqueous humour and the cerebrospinal fluid contain anti- Leishmania IgGs and that the specificity of antigen recognition of these fluids is similar to that of the sera. We also show that in the encephalon and cerebellum of these dogs there is a pathological sponge-like reaction accompanied by neuronal degeneration, mobilization of glial cells together with accumulation of amyloid deposits. The interstitial and intravascular deposition of IgGs and Leishmania antigens in choroid plexus suggest that in these animals there is a failure of the blood-cerebrospinal and ciliary bodies filtration barriers which may allow the transfer of anti- Leishmania IgGs from the blood stream to these fluids. We suggest that the failure of the blood-cerebrospinal barrier and the in situ concentration of anti- Leishmania IgGs and antigens in brain tissues may predispose to the pathological features detected in this compartment.     

Amyloidosis in experimental tegumentary leishmaniasis in mice

Renal and hepatosplenic amyloidosis was found in chronic cutaneous leishmaniasis in mice infected with 10(6) purified amastigotes from lesions produced by the H21 strain of Leishmania mexicana amazonensis. After 1 year a progressive lesion leading to metastasis was observed in most animals.     

塔里木盆地荒漠型黑热病宿主动物调查研究

目的调查并查找新疆塔里木盆地荒漠型黑热病自然疫源地的宿主动物。方法参考世界卫生组织(WHO)黑热病宿主动物的5个标准,采用流行病学方法查明荒漠型黑热病患者被感染的主要生境;采集疫区不同生境优势动物,以特异性抗体检测方法筛查抗体阳性动物;调查疫区不同生境白蛉密度和传播媒介吴氏白蛉自然感染利什曼原虫的感染率;采用特殊培养基和敏感动物从患者、阳性动物和吴氏白蛉中分离利什曼原虫,开展分子遗传学相似性鉴定;以吴氏白蛉开展优势动物吸血实验,查找吴氏白蛉的供血宿主;对照黑热病宿主动物的5个标准,根据上述实验调查结果,采用排除法确认天然宿主动物,同时确认荒漠型黑热病疫区的核心区;黑热病暴发时在核心区及其周边以杀虫剂灭蛉,与对照区比较,根据两个区的实际控制效果和时间,最后确定宿主动物。结果荒漠型黑热病患者被感染的生境是胡杨柽柳生境及其相邻农田;胡杨柽柳生境的优势动物为塔里木兔(Lepus yarkandensis)、子午沙鼠(M.meridianas)、毛脚三趾跳鼠(D.sagitta)和科氏三趾矮跳鼠(S.crassicada);共获得16种动物1374份样品(野生动物1137份、家畜237份),只有塔里木兔(45/485)检出抗利什曼原虫阳性个体,从塔里木兔分离出4株利什曼原虫(4/485)。在疫区的所有生境中,只有胡杨柽柳生境中的塔里木兔的抗体阳性率和吴氏白蛉的利什曼原虫感染阳性率最高;吴氏白蛉只能吸到塔里木兔和大耳猬的血,吸血率分别为9.5%和3.3%;塔里木兔的利什曼原虫分离株与当地黑热病患者和传播媒介吴氏白蛉分离株的乙酰氨基葡萄糖磷酸转移酶(NAGT)核基因鉴定结果显示相似性100%,属婴儿利什曼病2型;自2008年黑热病暴发以来,实验区飞机喷洒杀虫剂灭蛉一次,连续7年无流行,对照区流行2次,每次流行持续2年。结论所有动物中只有塔里木兔与WHO规定的黑热病宿主动物的5个标准最接近,传播媒介吴氏白蛉的供血宿主实验是验证天然宿主动物的重要方法;荒漠型黑热病患者被感染的生境是查找黑热病宿主动物的关键区域,即胡杨柽柳核心区及其相邻农田;核心区灭蛉是长期有效控制黑热病流行的重要措施,能为证明荒漠型黑热病宿主动物提供重要证据。     

Detection and enumeration of Leishmania in sand flies using agar-based media

An agar plating technique was used to determine the number of amastigotes ingested by Lutzomyia longipalpis fed on papules on Mesocricetus auratus caused by Leishmania mexicana amazonensis and on lesions on Mystromys albicaudatus caused by Leishmania braziliensis panamensis. The technique involved homogenizing sand flies after bloodfeeding on the infected animals and spreading the homogenate over the surface of agar plates. A great variation in the number of amastigotes ingested by individual sand flies was demonstrated. Not all amastigotes ingested developed anterior stomodeal infections.