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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   

3.

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.

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4.
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   

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.
A sample of 22 Echinococcus granulosus isolates collected from 12 sheep and ten humans from a focus of cystic echinococcosis in western Turkey was examined by DNA sequencing of four mitochondrial genes (cox1, atp6, nad1, rrnS). Results demonstrated the presence of two species of E. granulosus complex, E. granulosus sensu stricto and E. canadensis. Of E. granulosus sensu stricto, the G1 genotype (including three microvariants) was found in 17 isolates from humans and sheep, the G3 genotype and an intermediate form G1/G3 in one isolate each (both from sheep). Of E. canadensis, the pig strain G7 was found in three isolates from sheep and human. This is the first report of this strain in Turkey. Its presence has implications for local control programs due to its shorter maturation rate in dogs compared with E. granulosus sensu stricto. Goat and/or wild boar are likely reservoirs for G7 in the region. We provided further data on the pattern and frequency of nucleotide substitutions within the G1/G3 cluster. Based on our results and GenBank records, G2 (Tasmanian sheep strain) is not considered as a discrete genotypic unit, as its sequences at polymorphic sites conform to microvariants of both G1 and (more often) G3.  相似文献   

7.
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   

8.
Control measures to prevent human infections with the food-borne zoonotic helminth Taenia saginata are currently based on meat inspection, which shows rather low diagnostic sensitivity. To develop an immunoblot for detection of T. saginata-infected cattle, crude proteins of T. saginata cysts were extracted and separated with SDS-PAGE. The cyst antigens showed ten protein bands ranging from 260 to 14 kDa. T. saginata cyst proteins 260, 150, 130, 67, 60, 55, 50, and 23 kDa were immunoreactive with known positive sera of T. saginata-infected cattle but cross-reacted with sera from Echinocccus granulosus-infected ruminants. By contrast, 14- and 18-kDa cyst proteins reacted specifically with T. saginata-positive sera and thus might be potential candidates for the development of a T. saginata-specific immunoassay. Proteins of E. granulosus cysts and Taenia hydatigena cysts were also extracted and separated with SDS-PAGE. E. granulosus cysts revealed 11 protein bands ranging from 260 to 23 kDa. E. granulosus protein 60 kDa was immunoreactive with E. granulosus-positive sera only. The cyst of T. hydatigena showed 11 protein bands ranging from 290 to 14 kDa. The protein band 35 kDa showed cross-reaction with positive sera from both T. saginata- and E. granulosus-infected animals. A protein of 67 kDa was present in all three tested cestode species and was the major antigenic protein detected by sera of T. saginata- and E. granulosus-infected animals. Therefore, this protein represents a potential vaccine candidate against both cysticercosis and cystic echinococcosis in cattle.  相似文献   

9.
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   

10.
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   

11.
In Argentina, hydatid disease caused by Echinococcus granulosus is widespread. The south of Buenos Aires province, Argentina, is one of the three regions where hydatidosis is endemic. Although domestic dogs and sheep are considered to be the main hosts for E. granulosus, the potential role of wildlife in the local transmission of E. granulosus has not been investigated. The aim of this study was to estimate the hydatidosis/echinococcosis prevalence in European hare (Lepus europaeus) and Pampas fox (Lycalopex gymnocercus), two abundant species with a strong predator–prey relationship in rural areas of Buenos Aires province using different diagnostic tests. A total of 61 fox intestines were examined, finding that 52 (85.2 %) harbored at least one helminth species. However, no adult or immature form of Echinococcus sp. was found in the intestinal contents. Coproparasitological analysis and Copro–ELISA followed by Copro–PCR were used as supplementary diagnostic tests. Only one (1.7 %) of 59 fecal samples was positive to Taeniidae eggs by coproparasitological analysis, but this same sample was negative by the Copro–ELISA test. The analysis by Copro–ELISA showed 6 of 57 (10.6 %) positive samples, but the Copro–PCR tests carried out on these samples were negative to E. granulosus. A total of 6,808 lungs, 3,576 livers, and 3,542 hearts of hunted hares were examined and palpated, but no structure resembling hydatid cysts were detected. Our results suggest that hares and Pampas foxes are not currently important wild reservoirs of E. granulosus in the studied area.  相似文献   

12.
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   

13.
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   

14.
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   

15.
The specificity of infection-induced immunity in mice infected with cultured or host-adapted Borrelia burgdorferi sensu lato, the agent of Lyme disease, was examined. Sera obtained from mice following infection with high and low doses of cultured B. burgdorferi sensu stricto, transplantation of infected tissue (host-adapted spirochetes), or tick-borne inoculation all showed protective activity in passive immunization assays. Infection and disease were similar in mice infected with cultured spirochetes or by transplantation. Thus, the adaptive form of inoculated spirochetes did not influence the immune response during active infection. Mice infected with B. burgdorferi sensu stricto and then cured of infection with an antibiotic during early or late stages of infection were resistant to challenge with high doses of homologous cultured spirochetes for up to 1 year. In contrast, actively immune mice infected with different Borrelia species (B. burgdorferi sensu lato, B. burgdorferi sensu stricto cN40, Borrelia afzelii PKo, and Borrelia garinii PBi) and then treated with an antibiotic were resistant to challenge with cultured homologous but not heterologous spirochetes. Similar results were achieved for actively immune mice challenged by transplantation and by passive immunization with sera from mice infected with each of the Borrelia species and then challenged with cultured spirochetes. Arthritis and carditis in mice that had immunizing infections with B. afzelii and B. garinii and then challenged by transplantation with B. burgdorferi sensu stricto were equivalent in prevalence and severity to those in nonimmune recipient mice. These results indicate that protective immunity and disease-modulating immunity that develop during active infection are universal among species related to B. burgdorferi sensu lato but are species specific.  相似文献   

16.
Echinococcosis is one of the most important parasitic zoonotic diseases in the world. The life cycle of Echinococcus granulosus is dependent to the dog–sheep cycle and is actively transmitted in all pastoral regions where sheep, cattle and camels predominate. DNA approaches are now being used routinely for accurate identification of Echinococcus and Taenia species, subspecies and strains. In this study, faecal samples were collected from 50 stray dogs from Mashhad city in the northeast of Iran during June 2011. All samples were frozen at least for 1 week in ?80°C. The embryophore layer of the eggs was broken by freezing–thawing method after egg concentration by the formalin-ether method. DNA was extracted using a DNA isolation kit (MBST, Germany/Iran) according to the manufacturer’s instructions. After PCR, by the primers expressed in the following it became, clear that about 20 % of stray dogs are infected with E. granulosus. In this study, we describe a modified method for DNA isolation from faeces for coprodiagnosis of Echinococcus spp.  相似文献   

17.
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   

18.
We have studied the immune response to a variable surface-exposed loop region of the P66 outer membrane protein from Borrelia burgdorferi sensu lato by using an enzyme immunoassay. Lyme borreliosis populations found in North America and Sweden were preferentially more seroreactive to P66 from their respective regional species, namely, B. burgdorferi sensu stricto and B. garinii and B. afzelii, respectively.  相似文献   

19.
Species-specific sequences were shown to be carried by plasmids of the three main species of Borrelia burgdorferi sensu lato involved in Lyme disease. Libraries of the 16-, 33-, and 25-kb plasmids of B. burgdorferi sensu stricto, Borrelia garinii, and Borrelia afzelii, respectively, were then built and used to isolate species-specific sequences. After sequencing of the cloned inserts, three sets of primers were designed. They were shown to determine species-specific PCR amplification products. The sensitivities of the PCR assay with these primers were 100 spirochetes for B. burgdorferi sensu stricto and 1,000 spirochetes for B. garinii and B. afzelii. The usefulness of these primers for the identification of species in biological samples (tick, serum, and cerebrospinal fluid samples) was ascertained.  相似文献   

20.
Parasitology Research - Recent surveys at slaughterhouses confirmed the presence of three different species of Echinococcus granulosus sensu lato in France: E. granulosus sensu stricto, E....  相似文献   

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