首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
2.
Cystic echinococcosis (CE) due to the formation of a hydatic cyst is a disease commonly seen in humans and animals that can be mortal sometimes. This disease, which is present in many countries around the world, constitutes a great problem for public health and the economy. The aim of this study was to identify Echinococcus granulosus genotypes in formalin-fixed, paraffin-embedded tissues. Tissue samples from 70 human patients with histologically confirmed echinococcosis were analysed by direct PCR of the 12S rRNA gene and by DNA sequence analysis of the CO1 gene of E. granulosus. Of the 70 samples, 29 (41.6%) could be genotypically characterized. Specifically, 26 of 70 were positive by direct G1-3 PCR of the 12S rRNA gene, two of which were identified as G1 by additional CO1 gene sequencing. All the 44 unidentified samples underwent CO1 sequencing, which yielded one G3 and two G6 records, while the remaining 41 samples gave no or inconclusive results. In conclusion, the results from the analysis of human isolates of E. granulosus confirmed the occurrence of G1, G3 and G6 genotypes in Turkey and indicated G1/G3 cluster (E. granulosus sensu stricto) as the predominant genotype.  相似文献   

3.
Hydatid cyst is a chronic zoonotic disease caused by the larval stage of the dog tapeworm, Echinococcus granulosus. To identify genotype of hydatid cysts of human and sheep jackal in Ilam Province (South West of Iran), the PCR-RFLP and DNA sequencing were used. A total of 10 human and 20 sheep protoscoleces hydatid cyst samples were collected from different hospitals and slaughterhouses. Then, the gene of cox1 of mitDNA of the parasite was amplified and PCR products were cut using AluI and HpaII restriction enzymes. Finally, a number of PCR products were bi-directionally sequenced. Based on the DNA sequencing and PCR-RFLP results, human and sheep samples indicated to pertain the genotypic similarities. Our data indicated that, the genotypes of larval stage of E. granulosus is similar in both intermediate hosts. According to the phylogenetic tree, there is at least one genotype of parasite, which belongs to E. granulosous sensu stricto (G1–G3) complex and overall isolates sequences of mtDNA indicated 100 % homology with references G1, G2, and G3 sequences in the GenBank database. G1 genotype was the dominant genotype of human and livestock.  相似文献   

4.
Cystic echinococcosis is a zoonosis caused by the tapeworm Echinococcus granulosus sensu lato. The lifecycle of the parasite is mainly domestic, requiring dogs as definitive hosts and livestock species as intermediate hosts. Although human cystic echinococcosis is a high public health priority in the Republic of Moldova, the rare animal data available concerns only infection in cattle. A preliminary slaughterhouse survey was conducted to assess prevalence and perform the first molecular characterization of E. granulosus sensu lato in sheep and cattle. For the survey, 40 sheep and 19 cattle were inspected. Very high prevalence in sheep (82.5 %) and in cattle (78.9 %) was found. Molecular analyses identified genotypes G1 and G3 of E. granulosus sensu stricto in all the liver and lung samples. Based on the concatenated sequences of cox1?+?nad3 (701 bp), 23 different haplotypes were obtained. Mixed infections by different haplotypes/genotypes were frequently identified in both sheep and cattle. The relatively high (20.0 %) cyst fertility observed in cattle argues for the potential contribution of cattle to the lifecycle of E. granulosus sensu stricto, unlike previous observations in Europe. The hyperendemic situation of Moldova can be explained by a high majority of animals slaughtered at home usually without veterinary inspection. Further extensive slaughterhouse surveys with molecular identification also involving pigs and goats are needed to obtain a better overview of the epidemiological situation of E. granulosus sensu lato in this hyperendemic focus in the Republic of Moldova.  相似文献   

5.
Cystic echinococcosis (CE) is a widespread and severe zoonotic disease caused by infection with the larval stage of the eucestode Echinococcus granulosus sensu lato. The polymorphism exhibited by nuclear and mitochondrial markers conventionally used for the genotyping of different parasite species and strains does not reach the level necessary for the identification of genetic variants linked to restricted geographical areas. EmsB is a tandemly repeated multilocus microsatellite that proved its usefulness for the study of genetic polymorphisms within the species E. multilocularis, the causative agent of alveolar echinococcosis. In the present study, EmsB was used to characterize E. granulosus sensu lato samples collected from different host species (sheep, cattle, dromedaries, dogs, and human patients) originating from six different countries (Algeria, Mauritania, Romania, Serbia, Brazil, and the People''s Republic of China). The conventional mitochondrial cox1 and nad1 markers identified genotypes G1, G3, G5, G6, and G7, which are clustered into three groups corresponding to the species E. granulosus sensu stricto, E. ortleppi, and E. canadensis. With the same samples, EmsB provided a higher degree of genetic discrimination and identified variations that correlated with the relatively small-scale geographic origins of the samples. In addition, one of the Brazilian single hydatid cysts presented a hybrid genotypic profile that suggested genetic exchanges between E. granulosus sensu stricto and E. ortleppi. In summary, the EmsB microsatellite exhibits an interesting potential for the elaboration of a detailed map of the distribution of genetic variants and therefore for the determination and tracking of the source of CE.Cystic echinococcosis (CE) is a widespread and severe zoonosis caused by infection with the larval stage of the eucestode Echinococcus granulosus sensu lato. Classification of the organisms within this paraphyletic taxon has undergone and continues to undergo important changes. Mitochondrial DNA-based studies have shown that E. granulosus sensu lato is composed of 10 heterogeneous groups of variants, defined as strains (strains G1 to G10) (5, 6, 17). However, these strains are now reorganized within distinct species (21, 25). E. granulosus sensu stricto encompasses strains G1, G2, and G3; E. equinus corresponds to strain G4; and E. ortleppi comprises strain G5. Strains G6, G7, G8, G9, and G10 have been also classified under a well-supported monophyletic species, E. canadensis (16, 19, 21). Recently, the lion strain has been characterized as another new species, E. felidis (11).Currently, mitochondrial and nuclear markers are not sufficiently polymorphic for use for the identification of genetic variations that could reflect geographically based peculiarities. The use of sensitive tools such as microsatellites may provide more information about the polymorphism of the parasite and the spatial-temporal characteristics of its patterns of transmission between foci. However, to date, only four single-locus microsatellites have been used to investigate E. granulosus sensu lato isolates: U1snRNA, EgmSca 1, EgmSca 2, and EgmSga 1. The U1snRNA gene exhibited 11 distinct profiles: 8 for E. granulosus sensu stricto (G1/G2), 2 for E. ortleppi (G5), and 1 for E. canadensis (G6) (22). However, no spatial correlation with the geographic origin of the isolates was observed. Among the three microsatellites described by Bartholomei-Santos et al. (4), only EgmSca 1 correlated the genotypes with the origins of the samples.Recently, Bart et al. (3) developed EmsB, a tandemly repeated multilocus microsatellite, for the genotyping of E. multilocularis. This marker showed a higher level of intraspecific variability compared with that shown by any previously published marker, as well as a very high degree of sensitivity (7, 13-15). It is composed of an array of 800-bp DNA fragments containing a variable combination of CA and GA repeats. The use of such a microsatellite could contribute to the better identification of the spatial-temporal characteristics of the E. granulosus transmission patterns, as is the case for E. multilocularis. Indeed, using this new tool, Knapp et al. managed to perform efficient genetic tracking of E. multilocularis isolates in different foci of alveolar echinococcosis (13-15). Furthermore, because of its localization within the nuclear genome, cross-fertilization processes may modify EmsB patterns. Therefore, this microsatellite may be an interesting marker for use for both assessment of the genetic polymorphism of E. granulosus sensu lato and detection of the genetic exchange events between the variants.In the present work, we tackled its variability using a panel of 127 E. granulosus sensu lato samples collected in six countries where CE is endemic.  相似文献   

6.
Echinococcus granulosus is the aetiological agent of cystic echinococcosis (CE), which is a public health problem in many eastern European countries, particularly in Romania, where the infection causes a high number of human and animal cases. To shed light on the transmission patterns of the parasite, we performed a genotyping analysis on 60 cyst samples obtained from patients who live in south-eastern Romania and who underwent surgery for liver or lung CE. DNA was extracted from the endocysts or the cyst fluids, and fragments of cytochrome c oxidase subunit 1 and NADH dehydrogenase subunit 1 mitochondrial genes (cox1 and nd1, respectively) were amplified by PCR and sequenced. We found that most of the samples analysed (59/60) belonged to the G1–G3 complex (E. granulosus sensu stricto), which contains the most widespread and infective strains of the parasite. We also identified the first human patient infected by a non-G1–G3 genotype of E. granulosus in this country. As the DNA sequence of this cyst sample showed maximum homology with the G6–G10 complex (Echinococcus canadensis), this is, in all likelihood, a G7 genotype, which is often found in pigs and dogs in most countries of eastern and south-eastern Europe.  相似文献   

7.
Addressing the genetic variability in Echinococcus granulosus is epidemiologically important, as strain characteristics may influence the local transmission patterns of zoonotic cystic echinococcosis. To classify the genotype(s) present in intermediate (pig, cattle and sheep) and definitive (jackal and wolf) hosts in Bulgaria, a DNA-based approach was used to assess parasite protoscoleces or strobiles. Genes corresponding to coding and non-coding regions of the nuclear and mitochondrial genome (ND-1, HBX, Act II, AgB-1) were amplified by PCR and subsequently sequenced. The sequences resolved were all found to be identical to those published for the common sheep strain of E. granulosus, indicating that the G1 genotype is predominant in Bulgaria. One microvariant for ND-1 was found in the pig isolates; however no epidemiological significance was attributed to this finding.  相似文献   

8.
Investigations were undertaken to determine the genotypes of the parasite Echinococcus granulosus that were present in livestock animals on the island of Sardinia. Liver, lung, and spleen samples were obtained from 770 sheep, 229 cattle, and 277 pigs slaughtered in Sardinia between January 2003 and April 2005, and the number and fertility of hydatid cysts were determined. Protoscoleces and/or germinal layer were collected from individual cysts, DNA was extracted from 91 samples, and polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism (RFLP) methods were used for identification of the strain genotype for each sample (G1, G5, G6/G7). Fragments of the mitochondrial cytochrome c oxidase subunit 1 and NADH dehydrogenase I were sequenced. Hydatid disease prevalence of 75.3, 41.5, and 9.4% were found in the organs collected from sheep, cattle, and pigs, respectively. Molecular analysis showed that 89 of 91 ovine, bovine, and swine cysts belonged to the G1 genotype (common sheep strain) of E. granulosus. Parasite isolates from two pigs were identified to belong to the G7 genotype (pig strain). Our results confirm the high prevalence of E. granulosus infection in livestock animals in Sardinia and reveal the presence of at least two parasite genotypes in Sardinia.  相似文献   

9.
Nineteen hydatid cyst isolates collected from camels in central Iran were subjected to sequences analysis of mitochondrial cytochrome c oxidase subunit 1 (cox1) and NADH dehydrogenase subunit 1 (nad1) genes. A consensus sequence obtained containing 366 nucleotides for cox1 and 471 nucleotides for nad1 genes. Overall, the camel isolates indicated five different sequences in cox1 and nine in nad1 genes. The sequences analysis indicated that 26.3%, 42.1%, and 31.6% of isolates belonging to G1, G3, and G6 genotypes of Echinococcus granulosus, respectively. The isolates with G3 genotype indicated one cox1 sequence having 100% homology with reference G3 sequence (AN: M84663) and two different nad1 sequences, one having100% homology with reference G3 sequence (AN: AJ237634) and the other with a silent mutation (G to A) in position 279. The presence of G3 genotype (buffalo strain) of E. granulosus as dominant genotype in camels is emphasized. As G3 genotype has formerly been reported in human, the epidemiological role of camels is warranted in future surveys.  相似文献   

10.
Human cystic echinococcosis (hydatid disease) caused by the Echinococcus granulosus tapeworm continues to be a substantial cause of morbidity and mortality in many parts of the world. France is still considered as endemic area, but the current infestation by E. granulosus of intermediate hosts in France remains currently unknown due to the absence of official data reporting for the last 20 years. A 1-year prevalence survey was conducted in the 24 slaughterhouses of ten departments of the South of France. We demonstrate that the E. granulosus parasite is still currently present at low prevalence at slaughterhouses in the study area (4 cases for 100,000 sheep and 3 cases for 100,000 cattle). In addition, we assess the presence of genotype G1 in infected animals and identify for the first time in France genotypes G2 and G3 of E. granulosus sensu stricto.  相似文献   

11.

Cystic echinococcosis (CE) of humans and animals is caused by various species of Echinococcus granulosus sensu lato. Of these, E. granulosus sensu stricto has the widest geographical distribution and is the most important agent of human cystic echinococcosis. Previous molecular studies showed that E. granulosus s.s. isolates from the Middle East and western Asia exhibit higher intraspecific diversity than those from other parts of the world, which led to hypotheses on the origin of the species in that region. However, various high-endemicity regions have not been sufficiently covered by such studies, including northern Africa as a well-known focus of this parasite. Here, we report data on the mitochondrial cox1 gene (1609bp) sequence diversity of E. granulosus s.s. from Algerian livestock. An abattoir survey of 1278 animals from the Algerian steppe region (Djelfa) resulted in CE prevalence of 13.9% in cattle (n = 266), 5.7% in sheep (n = 975), and 0% in goats (n = 37). All of 125 molecularly examined cyst isolates belonged to E. granulosus s.s. In total, 73 haplotypes were found, only five of which have been previously reported (from the Middle East and Australia). One haplotype sequence (EgAlg01X) was found to contain an insertion of three bases at the end of the gene. To the best of our knowledge, this has not been reported before for Echinococcus spp. Diversity values of our panel of Algerian samples were in the range of those that have been previously reported from the Middle East and far higher than those from elsewhere. This, together with the low number of shared haplotypes, indicates a more complex biogeographical history of this parasite than hitherto assumed.

  相似文献   

12.
The taxonomic and phylogenetic status of Echinococcus granulosus strains are still controversial and under discussion. In the present study, we investigated the genetic polymorphism of E. granulosus isolates originating from three countries of Africa, including a region of Algeria, where the common G1 sheep and the camel G6 strains coexist sympatrically. Seventy-one hydatid cysts were collected from sheep, cattle, camels, and humans. Two mitochondrial markers (cox1 and nad1) were used for strain identification. Two nuclear markers (actII and hbx2) were used to study the possible occurrence of cross-fertilization. Despite the heterogeneity observed among the G1 isolates, they were all localized within one robust cluster. A second strong cluster was also observed containing all of the G6 isolates. Both strains appeared as two distinct groups, and no cases of interbreeding were found. Thus, the attribution of a species rank can be suggested. We also found the Tasmanian sheep G2 strain for the first time in Africa. Because of the slight variations observed between the common sheep and the Tasmanian sheep strains, further studies should be carried out to elucidate the epidemiological relevance of this genetic discrimination.  相似文献   

13.
Although cystic echinococcosis (CE) has been a recognized public health problem in Greece, molecular data are lacking regarding the types and prevalences of infecting strains of the etiological agent Echinococcus granulosus. Therefore, we investigated the prevalence of CE and determined the infecting genotypes in sheep and goats in Peloponnesus, a large region of southern Greece. Liver and lung samples were obtained from 210 sheep and 190 goats slaughtered between January and December 2005, and the number, morphology, and fertility of hydatid cysts were determined. Protoscoleces or germinal layers were collected from individual cysts (20 sheep and 20 goats), and DNA was extracted. A polymerase chain reaction (PCR)/seminested PCR system was used to distinguish the G1, G5, and G6/G7 strains, and a specific molecular diagnosis was obtained by sequencing PCR-amplified mitochondrial DNA encoding cytochrome c oxidase subunit 1 and NADH dehydrogenase I genes. The prevalence of CE was 30.4% in sheep and 14.7% in goats; fertile cysts were found in 16.2 and 7.4%, respectively. Overall, 18 of 20 sheep harbored the G1 genotype (common sheep strain), while the remaining two animals had the G3 (buffalo) strain. All 20 goats were infected with the G7 (pig) strain. These results document the prevalence of E. granulosus infection in food animals in this geographical area and reveal for the first time the presence of, at least, three parasite genotypes.  相似文献   

14.
Reliable and rapid genotyping of large number of Echinococcus granulosus sensu lato isolates is crucial for understanding the epidemiology and transmission of cystic echinococcosis. We have developed a method for distinguishing and discriminating common genotypes of E. granulosus s.l. (G1, G3, and G6) in Iran. This method is based on polymerase chain reaction coupled with high resolution melting curve (HRM), ramping from 70 to 86 °C with fluorescence data acquisition set at 0.1 °C increments and continuous fluorescence monitoring. Consistency of this technique was assessed by inter- and intra-assays. Assessment of intra- and inter-assay variability showed low and acceptable coefficient of variations ranging from 0.09 to 0.17 %. Two hundred and eighty E. granulosus s.l. isolates from sheep, cattle, and camel were used to evaluate the applicability and accuracy of the method. The isolates were categorized as G1 (93, 94, and 25 %), G3 (7, 4, and 4 %), and G6 (0, 2, and 71 %) for sheep, cattle, and camel, respectively. HRM results were completely compatible with those obtained from sequencing and rostellar hook measurement. This method proved to be a valuable screening tool for large-scale molecular epidemiological studies.  相似文献   

15.
Cystic echinococcosis (CE) is a zoonotic disease caused by several members of the Echinococcus granulosus species complex. In East Africa, several species/strains are known to occur in livestock and humans, but host preferences, relative frequencies and spatial distribution of these taxa are poorly known. Here, we contribute livestock data for Maasailand of southern Kenya. Total CE prevalence was 25.8?% in cattle (151/587), 16.5?% in sheep (71/430) and 10.8?% in goats (21/194), which is a significant increase compared to surveys done about three decades ago. The majority of cysts occurred in the liver (56?% in cattle, 70?% in sheep and 65?% in goats). Molecular characterization by PCR?CRFLP and sequencing of parts of the mitochondrial nad-1 gene was done for a subsample of 285 cysts. E. granulosus G1 was dominant in all host species (200 of 201 cysts from cattle, 68 of 69 from sheep and 11 of 15 from goats); the remaining taxa were Echinococcus canadensis G6 (one cyst from sheep, four from goats) and Echinococcus ortleppi (one cyst from cattle). Considering cyst fertility, sheep appear to be the most important hosts for E. granulosus G1, while goats were found to be suitable hosts for E. canadensis G6 (three of four cysts were fertile). For the first time, E. ortleppi was found in cattle from southern Kenya. Our data show an intense and possibly increasing level of CE transmission in southern Kenya, and the predominance of E. granulosus G1, which appears to be particularly pathogenic to humans, calls for urgent control measures.  相似文献   

16.
An epidemiological and molecular survey was conducted to investigate the role of cattle in the transmission chain of cystic echinococcosis (CE) in the Campania region of southern Italy. Out of a total of 434 cattle examined for CE, 45 (10.4%) were found infected. A total of 363 cysts were collected from the infected animals: 239 in the liver and 124 in the lungs. The cysts were either sterile (42.7%) or calcified/caseous (57.3%); no fertile cysts were found. Most of the cysts had sizes <3 cm (77.1%) and were unilocular (78.8%). The results of the linear regression model did not show any significant correlation between the age of infected cattle and the number of cysts. The sequencing of the mitochondrial cytochrome C oxidase subunit 1 (CO1) gene of 40 hydatid cysts produced sequences of 419 bp for each sample analyzed. Alignment of the obtained sequences with those present in GenBank showed 100% identity with the common sheep G1 (n = 21 cysts), the Tasmanian sheep G2 (n = 2 cysts), and the buffalo G3 (n = 17 cysts) strains, which constitute the species Echinococcus granulosus sensu stricto. The findings reported in the present study show that CE is widespread in cattle bred in the Campania region of southern Italy. However, the absence of fertile cysts and of the cattle strain (G5, E. ortleppi) suggests that cattle would not have any role in the persistence of this important zoonosis but rather a role as indicators of CE infection in this endemic area.  相似文献   

17.
Research on cystic echinococcosis (CE) has a long history in Kenya, but has mainly concentrated on two discrete areas, Turkana and Maasailand, which are known to be foci of human CE in Africa. Here, we report on a survey for CE in livestock from central to northeastern Kenya, from where no previous data are available. A total of 7,831 livestock carcasses were surveyed. CE prevalence was 1.92 % in cattle (n?=?4,595), 6.94 % in camels (n?=?216), 0.37 % in goats (n?=?2,955) and 4.62 % in sheep (n?=?65). Identification of the parasite was done using an RFLP-PCR of the mitochondrial nad1 gene, which had been validated before against the various Echinococcus taxa currently recognized as distinct species. From a total of 284 recovered cysts, 258 could be identified as Echinococcus granulosus sensu stricto (n?=?160), E. ortleppi (n?=?51) and E. canadensis (n?=?47) by RFLP-PCR of nad1. In cattle, fertile cysts occurred mostly in the lungs and belonged to E. ortleppi (31 of 54), while the vast majority were sterile or calcified cysts of E. granulosus s.s.. Most fertile cysts in camels belonged to E. canadensis (33 of 37); sterile or calcified cysts were rare. Goats harboured fertile cysts of E. ortleppi (n?=?3)—which is the first record in that host species—and E. canadensis (n?=?1), while all cysts of E. granulosus were sterile. Only sterile cysts were found in the three examined sheep. Typically, all cysts in animals with multiple infections belonged to the same species, while mixed infections were rare. Our data indicate that the epidemiological situation in central to northeastern Kenya is clearly different from the well-studied pastoral regions of Turkana and Maasailand, and the apparently low number of human CE cases correlates with the infrequent occurrence of E. granulosus s.s.  相似文献   

18.
Cystic echinococcosis (CE) is highly endemic in the Chinese province of Qinghai, located on the Tibetan Plateau. The Echinococcus granulosus sheep strain has already been reported in this focus. To improve our understanding of the role the parasite plays in the high prevalence observed in humans, we assessed the genetic polymorphism of 55 E. granulosus samples (37 from humans) using three discriminative mitochondrial markers: coxI, nadI and atp6. We obtained a total of 13 distinct genotypes which were all related to the common sheep G1 strain. Six of these genotypes have already been reported in China and other foci around the world. The remaining seven genotypes were new variants of the strain. The parasite population which was studied in the present work did not differ substantially from those observed in other foci of CE. Environmental conditions and human behaviour could explain the high incidence of the parasitic disease, particularly in the Tibetan population in the south of Qinghai, most of whom are livestock farmers.  相似文献   

19.
Echinococcosis/hydatidosis is one of the most important zoonotic diseases commonly found in different regions of Iran with a major economic and public health importance. In the current study, Echinococcus granulosus isolates were collected from hospitalized patients in Isfahan, central Iran. The genotypes of 30 samples were determined by polymerase chain reaction amplification of internal transcribed spacer-1 region of ribosomal DNA, followed by restriction fragment length polymorphism (RFLP) with two restriction enzymes namely AluI and MspI. As expected, each isolate yielded an approximately 1-kbp DNA fragment on the electrophoresis gel. According to RFLP results for both enzymes, all isolates had an equal pattern indicating the G1 genotype. Our findings confirmed that G1 is the dominant genotype of cystic echinococcosis in human in central Iran, with predilection to different organs including liver, lung, and brain, and warrants the importance of sheep dog cycle in public health.  相似文献   

20.
The intestinal contents of 27 Iberian wolves (Canis lupus signatus) from Spain were screened for the presence of the taenid cestode Echinococcus granulosus. Four animals were found positive (15% prevalence). The intensity of parasitation was variable (mean 71, range 1–147 E. granulosus per host). Gravid individuals were found in all wolves positive with the parasite. Molecular characterization of the parasite material showed that the wolf strain belongs to the G1 genotype. According to the results, we conclude that the Iberian wolf takes part in the maintenance of the life cycle of this zoonotic parasite in Spain and that this fact could have public health relevance.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号