Multiple genotypes of Taenia solium--ramifications for diagnosis,treatment and control

Mitochondrial DNA sequences of Taenia solium have fully been analyzed. Analysis of the full length of cytochrome c oxidase subunit 1 (1620 bp) and cytochrome b (1068 bp) genes of T. solium, isolated from Asia (China, Thailand, Indonesia and India), from Latin America (Mexico, Ecuador, Bolivia, Peru and Brazil) and from Africa (Tanzania, Mozambique and Cameroon), has revealed that the two phylogenies obtained were similar to each other regardless of the genes examined. The isolates from Asia formed a single cluster, whereas those from Latin America combined with those from Africa to form an additional cluster. It was estimated that these two genotypes emerged approximately 4-8 x 10(5) years ago. These results together with recent study of the ancient of human taeniid cestodes emerged several MYA in Africa, historical data on swine domestication, distribution of pigs and colonization patterns suggest that T. solium was introduced recently into Latin America and Africa from different regions of Europe during the colonial age, which started 500 years ago, and that T. solium of another origin independently spread in Asian countries, perhaps from China. Why did not T. solium of European origin invade or spread into Asia during the colonial age? Analysis of T. solium distribution must include other Taenia species, especially T. saginata and T. asiatica, which can not be differentiated from each other morphologically. BESS T-base analysis for differentiation of all human Taenia species including the two genotypes of T. solium, and T. saginata and T. asiatica has also been characterized. BESS T-base analysis differentiates African isolates from Latin American isolates as well but more samples should be analyzed for obtaining conclusive evidence for the latter. Serological analysis of cyst fluid of T. solium cysticerci obtained in China and Indonesia and from Mozambique and Ecuador indicates geographical differences in their banding patterns. These differences are discussed in the light of possible differences in pathology of T. solium worldwide. As it has been speculated that the ancient T. solium emerged several million years ago in Africa, it is necessary to analyze more isolates from Africa. Such working hypothesis may be evaluated combined with symptomatology and serology when we get additional DNA data from such areas, since there are some varieties of manifestation of neurocysticercosis with or without subcutaneous cysticercosis and of antigens of cyst fluid of T. solium from Asia and from Africa and/or America. Transfer of techniques of molecular identification and sero- and immuno-diagnoses between researchers and technicians from endemic countries using their own materials should be promoted with the aim of better international cooperation for the control of cysticercosis.     

An Andean origin of Phytophthora infestans inferred from mitochondrial and nuclear gene genealogies

Phytophthora infestans (Mont.) de Bary caused the 19th century Irish Potato Famine. We assessed the genealogical history of P. infestans using sequences from portions of two nuclear genes (beta-tubulin and Ras) and several mitochondrial loci P3, (rpl14, rpl5, tRNA) and P4 (Cox1) from 94 isolates from South, Central, and North America, as well as Ireland. Summary statistics, migration analyses and the genealogy of current populations of P. infestans for both nuclear and mitochondrial loci are consistent with an "out of South America" origin for P. infestans. Mexican populations of P. infestans from the putative center of origin in Toluca Mexico harbored less nucleotide and haplotype diversity than Andean populations. Coalescent-based genealogies of all loci were congruent and demonstrate the existence of two lineages leading to present day haplotypes of P. infestans on potatoes. The oldest lineage associated with isolates from the section Anarrhichomenun including Solanum tetrapetalum from Ecuador was identified as Phytophthora andina and evolved from a common ancestor of P. infestans. Nuclear and mitochondrial haplotypes found in Toluca Mexico were derived from only one of the two lineages, whereas haplotypes from Andean populations in Peru and Ecuador were derived from both lineages. Haplotypes found in populations from the U.S. and Ireland was derived from both ancestral lineages that occur in South America suggesting a common ancestry among these populations. The geographic distribution of mutations on the rooted gene genealogies demonstrate that the oldest mutations in P. infestans originated in South America and are consistent with a South American origin.     

广西4地带绦虫分离株COX1序列分析

目的 分析广西4地带绦虫分离株COX1序列, 了解亚洲绦虫在广西的分布。方法 对鹿寨、 融水、 田东、 三江等 4县现症病人进行驱虫, 收集绦虫成虫。绦虫成虫经反复洗涤后, 各取孕节一节, 研碎后提取基因组DNA; 同时设计特异性引物, PCR扩增各分离株COX1片段, 对扩增产物进行T?A克隆测序; 应用相关软件分析序列的同源性、 遗传距离, 同时构建系统发生树。同时, 从GenBank检索亚洲绦虫、 猪带绦虫和牛带绦虫COX1基因序列, 并与4地分离株基因序列进行比较。结果 广西4地5个带绦虫分离株的COX1碱基序列长度均为444 bp。鹿寨株与亚洲绦虫之间基因差异为5个位点（1.11%）, 同源性为98.87%, 遗传距离为0.011, 其在邻接法和简约法构建的系统发生树中位于同一分枝。融水A株与猪带绦虫同源性达100%, B株与牛带绦虫和亚洲绦虫的同源性分别达98.20%和96.17%; 田东和三江分离株与猪带绦虫的同源性分别为99.55%和96.40%, 遗传距离分别为0.005和0.037; 鹿寨株与牛带绦虫的同源性达96.40%。结论 广西鹿寨县存在亚洲绦虫流行, 融水县存在牛带绦虫和猪带绦虫混合流行。     

日本血吸虫线粒体DNA两个分子的遗传变异

目的　从线粒体DNA的2个分子,探讨我国日本血吸虫的遗传变异。　方法　试剂盒抽提基因组总DNA后,以特异性引物对线粒体还原型烟酰胺腺嘌呤二核苷酸(NADH)脱氢酶1(ND1)和细胞色素c氧化酶I(COI)进行PCR扩增,将PCR产物分别测序,并以生物信息学方法加以比较,构建系统进化树。　结果　序列系统进化树显示日本血吸虫中国大陆株与中国台湾株之间差异较大,在树状图中可归为2类;中国大陆山区型地域株,即云南洱源和四川天全在树状图中归为1类;中国大陆湖沼洲滩型地域株,即湖南岳阳、江西新建和安徽贵池3个地域株在树状图中处于并列位置;湖北省境内不同地域株在树状图中归为1类。　结论　我国各地日本血吸虫存在不同程度的遗传变异,各地域株间亲缘关系密切,存在共同的起源     

用mtCO技术测定云南及贵州四地区的牛带绦虫

目的　用mtCO技术鉴定云南省大理及贵州省都匀、从江等地所发现的是牛带绦虫或牛带绦虫亚洲亚种。　方法　采集成虫样本,抽提DNA,PCR扩增线粒体细胞色素C氧化酶(mtCO)部分基因片段并测序,经PHYLIP软件包处理,计算遗传距离并构建系统发育树状图。　结果　云南省兰坪、大理和贵州省都匀的标本mtCO基因片段序列与已知牛带绦虫亚洲亚种的序列相同。贵州从江的标本mtCO基因片段序列与已知牛带绦虫的序列相同。两组基因片段的同源性达97.44%,氨基酸序列同源性达99.16%。系统发育树状图显示,牛带绦虫亚洲亚种和牛带绦虫最为接近,远离猪带绦虫及其他绦虫。　结论　云南省兰坪、大理及贵州省都匀存在牛带绦虫亚洲亚种,贵州省从江发现的虫种为牛带绦虫。     

Taeniasis in Mongolia, 2002-2006

Survey on secondary data of taeniasis/cysticercosis was carried out in Mongolia in 2002-2006. A total of 118 taeniid proglottids, a diphyllobothriid segment, and 59 serum samples from 118 taeniasis cases were collected at National Center for Communicable Diseases, Ulaanbaatar, Mongolia. In 2006, 14 serum samples were collected from local people who had histories of epileptic seizures in Selenge Province where pig husbandry was the main business. The 118 proglottids were confirmed to be Taenia saginata by mitochondrial DNA analysis using cytochrome c oxidase subunit 1 and cytochrome b genes. T. saginata taeniasis was widely distributed at least in 10 of 21 provinces. No variation in the nucleotide sequences of the two genes was observed among T. saginata isolates from Mongolia. There was no evidence of Taenia solium taeniasis/cysticercosis or Taenia asiatica taeniasis. A diphyllobothriid segment was confirmed to be Diphyllobothrium latum by mitochondrial DNA analysis.     

分子分类结合形态学方法对云南大理带绦虫的鉴定

目的 鉴定云南大理洱源(E1-E2)、鹤庆(H1-H2)、双廊(SL)、挖色(WS)带绦虫的种.方法 首先对大理分离株带绦虫成虫进行形态学鉴定,从成虫节片中抽提DNA,PCR扩增线粒体DNA细胞色素B(mtDNA-Cyth)的部分序列并测序;结合GenBank中已知猪带绦虫、牛带绦虫和亚洲带绦虫mtDNA-Cytb序列,经DNAMAN软件处理后构建系统发育树状图.结果大理带绦虫E1的形态和牛带绦虫相似,系统发育树显示大理分离株E1、E2、SL、WS带绦虫标本与亚洲带绦虫的遗传距离最接近,距牛带绦虫较远,与猪带绦虫则更远.大理分离株H1、H2带绦虫标本与猪带绦虫的遗传距离最近,距牛带绦虫和亚洲带绦虫则较远.结论 经形态学和分子生物学鉴定,云南大理分离株E1、E2、SL、WS带绦虫标本属于亚洲带绦虫,而H1、H2株带绦虫标本属于猪带绦虫.     

Molecular identification of Taenia solium cysticercus genotype in the histopathological specimens

PCR-based molecular diagnosis was done for identification of causative agents found in paraffin-embedded specimens that were resected from two suspected neurocysticercosis patients. DNA samples were extracted from tissues or sections and cytochrome c oxidase subunit 1 gene and cytochrome b gene were amplified for the detection of taeniid DNA. Two different genes were successfully amplified in both specimens, but the sizes of amplified products seemed to depend on the quality of DNA. Based on the nucleotide sequences of the PCR-amplified genes, the causative agents from two cases were identified as T. solium Asian genotype. When infection with T. solium is not confirmed by histopathological examination, molecular diagnosis will be more useful for definitive diagnosis.     

甘肃省酒泉市狐狸源和犬源狮弓蛔虫线粒体pnad1和pnad5基因序列遗传变异研究

目的 探究甘肃省酒泉市不同宿主源狮弓蛔虫基因遗传变异。方法 应用PCR技术对甘肃省酒泉地区采集的11株分离自家犬、狐狸和宠物犬的狮弓蛔虫分离株线粒体烟酰胺腺嘌呤二核苷酸脱氢酶第1亚基部分序列基因（partial nicotinamide adenine dinucleotide dehydrogenase subunit 1, pnad1）和烟酰胺腺嘌呤二核苷酸脱氢酶第5亚基部分序列基因（partial nicotinamide adenine dinucleotide dehydrogenase subunit 5, pnad5）进行基因扩增,并对PCR扩增产物进行测序,分析其遗传变异。结果 获得的犬源和狐狸源狮弓蛔虫分离株pnad1和pnad5基因序列大小分别为530 bp和550 bp,不同分离株间核苷酸序列同源性分别为99.4%～100.0%和99.5%～99.8%,与已知狮弓蛔虫分离株对应序列同源性分别为99.2%～99.9%和99.1%～99.9%;分别检测到19个和24个遗传变异位点,单倍型分别为10和9个,单倍型多样性分别为0.982和0.964,核苷酸多样性分别为0....     

Clinical differentiation of inflammatory bowel disease (IBD) in Latin America and the Caribbean

The aim of the present study was to describe the epidemiological and clinical characteristics of inflammatory bowel disease (IBD), including medical and surgical treatments, in several countries in Latin America and the Caribbean.IBD is recognized as a global health problem because its incidence and prevalence have increased significantly over the last few years.This multicenter retrospective cohort study included 4714 patients with IBD diagnosed from 9 countries in Latin America and the Caribbean: Colombia, Cuba, Dominican Republic, Ecuador, Mexico, Peru, Puerto Rico, Uruguay, and Venezuela.Crohn disease (CD) was more frequent in Puerto Rico (71.9%), the Dominican Republic (61.0%), and Peru (53.1%). Ulcerative colitis was more frequent in Colombia (78.6%), Venezuela (78.2%), Mexico (75.5%), Cuba (69.9%), Ecuador (64.1%), and Uruguay (60.9%). The following clinical characteristics were more frequent in the Caribbean: penetrating behavior in CD, steroid dependence, steroid resistance, intolerance to thiopurines, extraintestinal manifestations, surgeries, hospitalizations due to IBD, and family history of IBD. The factors associated with the use of biological therapy were pancolitis in ulcerative colitis, penetrating behavior in CD, steroid resistance and dependence, presence of extraintestinal manifestations, and the need for surgery.This study from Latin America and the Caribbean demonstrated the different epidemiological and clinical characteristics of IBD.     

Genetic analysis of South American eastern equine encephalomyelitis viruses isolated from mosquitoes collected in the Amazon Basin region of Peru

Identifying viral isolates from field-collected mosquitoes can be difficult and time-consuming, particularly in regions of the world where numerous closely related viruses are co-circulating (e.g., the Amazon Basin region of Peru). The use of molecular techniques may provide rapid and efficient methods for identifying these viruses in the laboratory. Therefore, we determined the complete nucleotide sequence of two South American eastern equine encephalomyelitis viruses (EEEVs): one member from the Peru-Brazil (Lineage II) clade and one member from the Argentina-Panama (Lineage III) clade. In addition, we determined the nucleotide sequence for the nonstructural P3 protein (nsP3) and envelope 2 (E2) protein genes of 36 additional isolates of EEEV from mosquitoes captured in Peru between 1996 and 2001. The 38 isolates were evenly distributed between lineages II and III virus groupings. However, analysis of the nsP3 gene for lineage III strongly suggested that the 19 isolates from this lineage could be divided into two sub-clades, designated as lineages III and IIIA. Compared with North American EEEV (lineage I, GA97 strain), we found that the length of the nsP3 gene was shorter in the strains isolated from South America. A total of 60 nucleotides was deleted in lineage II, 69 in lineage III, and 72 in lineage IIIA. On the basis of the sequences we determined for South American EEEVs and those for other viruses detected in the same area, we developed a series of primers for characterizing these viruses.     

Phylogeny of human T cell lymphotropic virus type 1 in Peru: a high degree of evolutionary relatedness with South African isolates

We investigated the prevalence and molecular epidemiology of human T cell lymphotropic virus type 1 in Peruvian HIV-1-positive subjects, and found a 10.1% prevalence in a consecutive series of 318 HIV-1-positive patients living in Lima. Phylogenetic analysis of the long terminal repeat of 10 patient isolates showed that all of them belonged to the HTLV-1aA (Transcontinental) subgroup. Although the majority of the Peruvian sequences included in the analysis formed a clade with other Latin American sequences, the isolates of three patients clustered significantly with South African strains. These data show a high prevalence of HTLV-1 infection in HIV-1-positive subjects living in Lima and confirm the presence in Latin America of HTLV-1 strains probably arising from South Africa.     

头节小钩数目异常链状带绦虫的鉴定

目的对采自云南大理的3例寄生人体的3条小钩数目异常的疑似链状带绦虫进行虫种鉴定。方法肉眼观察虫体,镜下观察头节和孕节形态。提取3条带绦虫的孕节DNA,PCR扩增链状带绦虫细胞色素C氧化酶亚单位1基因(cox1)片段和全长基因,对其中1条的cox1全长基因的PCR产物测序。孵化虫卵,皮下注射感染9只小鼠,同时每只小鼠皮下注射地塞米松1mg/d×45d,感染60d后剖检,观察囊尾蚴形态。将虫卵喂食2只猕猴(2.5×105/只),47d后剖检,光镜和扫描电镜观察囊尾蚴形态,观察其肝脏的病理改变。结果3条疑似链状带绦虫头节顶突的小钩数目分别为0、4和10,孕节子宫单侧分支数为7～12。3条带绦虫cox1片段的链状带绦虫种特异性引物PCR结果均为阳性,cox1全长基因的测序结果表明,其与GenBank中多株链状带绦虫的cox1基因序列一致性为99.8%。小鼠皮下、猕猴肌肉和心脏均可检获囊尾蚴,经压片镜检可见头节上的4个吸盘和顶突,顶突上均有内外两圈共26～28个小钩。猕猴肝实质内见粟粒样病灶,组织切片显示,病灶周围纤维结缔组织增生,有嗜酸粒细胞浸润,部分囊腔内可见虫体结构。结论3条小钩数目异常的带绦虫为链状带绦虫,其幼虫可感染猕猴,引起肌肉型囊尾蚴病和肝囊尾蚴病。     

The close relationship between South African and Latin American HTLV type 1 strains corroborated in a molecular epidemiological study of the HTLV type 1 isolates from a blood donor cohort

It has been difficult to explain why all HTLV-1 sequences in Salvador, a city in the northeast of Brazil, belong to the Transcontinental (A) subgroup of the Cosmopolitan (a) subtype, since according to historical data the vast majority of slaves brought to Brazil (through Salvador) came from west Africa, where only the western African subgroup (C) has been found. To shed more light on this subject we conducted a phylogenetic analysis of 23 isolates from blood donors of Salvador. DNA was extracted and submitted to a nested PCR for amplification of the entire LTR region. The PCR products were purified and sequenced on an automated sequencer. Neighbor-joining and maximum likelihood phylogenetic analyses were performed. None of the new sequences from Salvador clustered within the West-African subgroup C. Confirming previous results, all sequences belonged to the Transcontinental subgroup (A) of the Cosmopolitan subtype, and clustered in two Latin American clusters. In addition we showed sequences from southern Africa clustering in both Latin American clusters. One of the new sequences is ancestral to the larger Latin American cluster beta due to a duplication of a 12-bp long fragment, a finding that has not been previously described. These findings support the hypothesis that HTLV-1 isolates circulating in Latin America have a closer relationship to South African compared to West-African HTLV-1 strains. The 12-bp-long duplications in one of the sequences has no obvious clinical or biological implications yet.     

Genetic analysis of ticks belonging to the Rhipicephalus sanguineus group in Latin America

Phylogenetic analyses based on mitochondrial 16S rDNA sequences were generated from Rhipicephalus sanguineus group specimens collected in 29 localities among 9 Latin-American countries, plus ticks collected in South Africa, Spain, and Italy. Sequences from Latin America generated six different haplotypes (A, B, C, D, E, and F). Phylogenetic analyses generated trees that segregated our tick sequences into two distinct clades: one is represented by haplotypes A–C, and South African R. sanguineus and Rhipicephalus turanicus ticks; the second clade is represented by haplotypes D–F, and European R. sanguineus and R. turanicus ticks. When haplotypes A–F are plotted in the Latin America map according to their geographical coordinates, it is clearly seen that haplotypes D–F are restricted to the southern portion of this continent, whereas haplotypes A–C are distributed in areas between northern Mexico and Brazil (except for the extreme south of this last country, where haplotype E was present). Hence, our phylogenetic analyses separated New World specimens of R. sanguineus into two distinct clades, one represented by tropical and subtropical populations (haplotypes A–C), here designated as the ‘tropical’ species. On the other hand, haplotypes D–F are here designated as the ‘temperate’ species because of their distribution in the southern portion of South America. Until recently, it was assumed that the R. sanguineus group was represented by a single species in the New World, namely R. sanguineus. While the present results coupled with recent studies support the presence of at least two species under the taxon R. sanguineus in the New World, they also show that even in the Old World, the taxon R. sanguineus might be represented by more than one species, since our phylogenetic analysis segregated European and South African R. sanguineus ticks into two distinct clades. The same can be applied for Spanish and South African R. turanicus.     

猪带绦虫45W蛋白疫苗的研制现状

猪囊尾蚴病是一种严重危害人类健康的人兽共患寄生虫病,主要流行于中非、南非、拉丁美洲、东亚和南亚等地区。采用疫苗防治该病是当前研究的热点。本文对45W蛋白的起源、编码基因和45W蛋白疫苗等方面的研究现状进行了综述。     

Diffusion of an idea: Jellinek's disease concept in Latin America

This paper examines the diffusion of Jellinek's disease concept of alcoholism in Latin America and its impact on research and prevention in those countries. After Jellinek's visit to Chile in 1956, epidemiological research in that country received a great impulse. Marconi published a series of papers where he put forward concepts of alcoholism based on Jellinek's work. These ideas were well received by alcohol epidemiologists and became standard definitions employed in a series of epidemiological studies in Chile, Argentina, Peru, Brazil, Costa Rica, and Mexico. Since then the disease concept has been the main idea governing professionals' understanding of alcohol problems in Latin America.     

Phylogenetic subtypes of human T-lymphotropic virus type I and their relations to the anthropological background.

Isolates of human T-lymphotropic virus type I (HTLV-I) were phylogenetically analyzed from native inhabitants in India and South America (Colombia and Chile) and from Ainu (regarded as pure Japanese descendants from the preagricultural "Jomon" period). Their genomes were partially sequenced together with isolates from Gabon in central Africa and from Ghana in West Africa. The phylogenetic tree was constructed from the sequence data obtained and those of previously reported HTLV-I isolates and simian T-lymphotropic virus type I (STLV-I) isolates. The heterogeneity of HTLV-I was recently recognized, and one major type, generally called the "cosmopolitan" type, contained Japanese, Caribbean, and West African isolates. The phylogenetic tree constructed in the present study has shown that this cosmopolitan type can be further grouped into three lineages (subtypes A, B, and C). Subtype A consists of some Caribbean, two South American, and some Japanese isolates, including that from the Ainu, in addition to an Indian isolate, and subtype B consists of other Japanese isolates in addition to another Indian isolate, suggesting that there might be at least two ancestral lineages of the Japanese HTLV-I. Subtype A implies a close connection of the Caribbean and South American natives with the Japanese and thereby a possible migration of the lineage to the American continent via Beringia in the Paleolithic era. Subtype C consists of the West African and other Caribbean isolates, indicating that not all but part of the Caribbean strains directly originated from West Africa probably during the period of slave trade. The tree also has shown that the HTLV-I isolate from Gabon in central Africa forms a cluster with STLV-I from a chimpanzee, suggesting a possible interspecies transmission between man and the chimpanzee in the past. No specific clustering was observed in the tree in relation to manifestations of the disease such as adult T-cell leukemia and HTLV-I-related neurological disorders. Thus, the topology of the phylogenetic tree reflects the movement of people carrying the virus in the past.     

以18SrRNA基因为分子标记的微小隐孢子虫系统发育研究

目的以18SrRNA基因为分子标记对分离自我国人和牛，以及澳大利亚和美国不同宿主来源微小隐孢子虫的系统发育进行探讨。方法用PCR扩增我国两个虫株的18SrRNA基因片段并进行序列测定，与登录于GenBank的澳、美两国虫株的相应序列进行比对。用NJ法构建分子系统树进行系统发育分析。结果分离自我国的小牛虫株（JLC）与GenBank中3个牛源虫株（澳大利亚的C1，美国的UCP和AUCP-1）亲缘关系近，位于系统发育树的同一枝；分离自我国的人源虫株（JSH）与澳大利亚鼠源虫株（M24）同源，共同位于系统发育树的另一枝。结论本研究中微小隐孢子虫株间亲缘关系的远近似主要由宿主因素决定，而受地理位置的影响较小。