Strains Of Echinococcus Granulosus Research Articles

Study on the genotypes of Echinococcus granulosus in yaks and sheep from Langkazi County in Tibet Autonomous Region of China based on mitochondrial cox1 and nad1.

To determine the genotypes of the epidemic strains of Echinococcus granulosus in livestock in Tibet, samples of E. granulosus cysts were collected from 11 yaks and 62 sheep. Genomic DNA was extracted from these samples, and gene fragments of mitochondrial cytochrome c oxidase subunit I (cox1) and NADH dehydrogenase subunit I (nad1) were amplified by PCR and sequenced. DNASTAR and MAGA7.0 were employed for homology analysis and phylogenetic tree construction. Echinococcus granulosus cysts were detected in 56.2% (41/73) of the samples screened. Of these, 63.4% (26/41) were identified as E. granulosus G1 genotype (common sheep strain), 24.4% (10 /41) as G3 genotype (buffalo strain), and 12.2% (5/41) were G6 genotype (camel strain). The study concludes that yaks and sheep in Langkazi county, Tibet, carry three E. granulosus genotypes (G1, G3, and G6), with the G1 genotype the predominant genotype in the region. This study clarifies the distribution of E. granulosus genotypes, providing genetic data and insight for the surveillance and prevention of echinococcosis.

Türkiye'deki Echinococcus granulosus sensu lato'nun genetik çeşitliliğine genel bir bakış

Echinococcus granulosus is a parasite that lives as a host in animals and humans, causes great economic damage and poses a serious threat to health. Morphological differences and intermediate host preference are used to distinguish the species of this parasite. Ten genotypes and lion strains of Echinococcus granulosus have been identified in molecular studies to date. It contributes to the fact that the effects of cystic echinococcosis detected in humans and the disease process caused by different genotypes can be handled differently. In genetic diversity analysis, species were classified as Echinococcus granulosus sensu stricto, Echinococcus equinus, Echinococcus ortleppi, Echinococcus canadensis and Echinococcus felidis genotypes. Echinococcus granulosus sensu stricto is the most common cause of human cystic echinococcosis worldwide and in Turkey. In this review, the distribution and epidemiology of Echinococcus granulosus genotypes detected in humans and animals in Turkey are discussed.

Employing NADH Dehydrogenase Subunit 1 in the Determination of Echinococcus granulosus Strain in Sheep, Cattle and Human in Thi-Qar Province, Iraq

Echinococcosis is a zoonotic disease caused by the larval stage of the tapeworm Echinococcus granulosus. This disease is an important public health and a significant economic issue in Iraq, where the lungs and livers are the popular places of infection. The aim of the current study focused on using the molecular techniques in the detection of an E. granulosus strain that causes cystic echinococcosis to human, sheep and cattle in Thi-Qar province, Iraq. In the current study, thirty isolates of E. granulosus were collected from 10 human hydatid cysts through surgery done at Al-Hussein Imam Teaching Hospital in Thi-Qar province and 10 sheep with 10 cattle hydatid cysts were obtained from the slaughterhouse in Thi-Qar province, Southern of Iraq to identify strains of E. granulosus which infect human and other intermediate hosts (sheep and cattle). The molecular study was carried out on the isolates and a specific primer set for the mitochondrial dehydrogenase NADH subunit 1 (NAD1) gene was used. This primer set was amplified 400 bp of the NAD1 gene in all selected isolates. The PCR products for the twelve selected isolates of E. granulosus (4 isolates per intermediate host) were sequenced and the results for these twelve isolates showed that all sequenced isolates, except one isolate Eg_5, belonged to the sheep strain G1 and a slight genetic diversity was observed with the reference sequences of the strain G1. The exception was in the isolate Eg_5 isolated from a cattle liver, which was similar to the buffalo strain G3. This study concludes that the common E. granulosus strain in Thi-Qar province is G1.

Genetic variants within the strains of Echinococcus granulosus by mitochondrial DNA sequencing

Genetic variants within the strains of Echinococcus granulosus by mitochondrial DNA sequencing

Multilocus sequence analysis of Echinococcus granulosus strains isolated from humans and animals in Iran

Echinococcus granulosus is now considered a complex consisting of at least four species and ten genotypes. Different molecular targets have been described for molecular characterization of E. granulosus; however, in almost all studies only one or two of the targets have been used, and only limited data is available on the utilization of multiple loci. Therefore, we investigated the genetic diversity among 64 strains isolated from 138 cyst specimens of human and animal isolates, using a set of nuclear and mitochondrial genes; i.e., cytochrome c oxidase subunit 1 (cox1), NADH dehydrogenase subunit 1 (nad1), ATPase subunit 6 (atp6), 12S rRNA (12S), and Actin II (act II). In comparison to the use of molecular reference targets (nad1 + cox1), using singular target (act II or 12S or atp6) yielded lower discriminatory power. Act II and 12S genes could accurately discriminate the G6 genotype, but they were not able to differentiate between G1 and G3 genotypes. As the G1 and G3 genotypes belong to the E. granulosus sensu stricto, low intra-species variation was observed for act II and 12S. The atp6 gene could identify the G3 genotype but could not differentiate G6 and G1 genotypes. Using concatenated sequence of five genes (cox1 + nad1 + atp6 + 12S + act II), genotypes were identified accurately, and markedly higher resolution was obtained in comparison with the use of reference markers (nad1 + cox1) only. Application of multilocus sequence analysis (MLSA) to large-scale studies could provide valuable epidemiological data to make efficient control and management measures for cystic echinococcosis.

The enzymes and electrolytes profiles in hydatid cyst fluid of naturally infected Iranian domestic ruminants.

Cystic echinoccoccosis is a zoonotic and prevalent disease which causes health problems and economic looses worldwide. The biochemical components of hydatid cyst fluid (HCF) have important role in metabolism and growth of unilocular hydatid cyst. The aim of the current study was to determine HCF level of enzymes and electrolytes profiles in naturally infected Iranian domestic ruminants. The livers and lungs infected with hydatid cysts were collected and HCF was aspirated from a total of 100 cysts obtained from livers (50 cysts) and lungs (50 cysts) of slaughtered domestic ruminants. Biochemical measurement of HCF was undertaken using colorimetric technique, refractometer, flame photometer, and biuret method. The enzyme levels of HCF were also measured by using appropriate kits. The average HCF level of calcium (Ca) was found to be significant higher in cattle (7.49±1.28mg/dl) and goats (13.98±5.11mg/dl) lungs. The average HCF level of phosphorous (P) was significantly higher in cattle livers (0.82±0.02mg/dl) than other examined animals. Measurement of the average HCF level of magnesium (Mg) was significantly lower in camel lungs (11.8±1.05mg/dl) than that in cattle livers (10.56±1.73mg/dl). The highest average HCF levels of Natrium (Na, 122.8±11.91mEq/l) and Kalium (Ka, 7.18±1.37mEq/l) were measured in sheep livers. The average HCF level of albumin (Alb) in infected lungs was significantly lower in cattle (0.48±0.01mg/ml) than camels (0.95±0.05mg/ml). The average HCF level of total protein (TP) in infected lungs was also lower in sheep (0.51±0.06mg/dl) than goats (3.21±0.51mg/dl). The highest average HCF level of creatine phosphokinase (CPK, 1229.25±13.21U/ml) and lactate dehydrogenase (LDH, 363.62±10.44U/ml) were measured in infected lungs of camels. It was concluded that HCF level of enzymes and electrolytes had differences in examined Iranian domestic ruminants which may be used to screen and help in characterization and identification of strains of Echinococcus granulosus.

Is there echinococcosis in West Africa? A refugee from Niger with a liver cyst

BackgroundItaly is presently facing an increase in immigration from sub-Saharan Africa through the Mediterranean Sea. Case reports of human cystic echinococcosis (CE) have been reported from most sub-Saharan countries. Therefore, an increase in the number of patients with CE coming from these areas in the Italian and European centers for infectious diseases is expected. Unfortunately, the epidemiology of CE in sub-Saharan countries is poorly known, which makes clinical suspicion and diagnosis of such infection difficult in patients coming from these areas.ResultsHere we report a case of hepatic CE in a patient from Niger who arrived in Italy through Libya and visited in a Tropical Medicine referral center in Northern Italy. The parasite was identified molecularly as the G6 “camel” strain of Echinococcus granulosus (E. canadensis). The diagnosis and management of a chronic and clinically complex infection like CE in such situation is difficult. Only 40 cases of CE from Niger have been reported; of these, 75% had extra-hepatic localization. To our knowledge, no strain characterization of human isolates from Niger has been reported so far. The CE cyst of the patient was in CE3a stage, indicating active transmission from the area in which the patient came. However, prevalence data from Niger, and from any other country in West Africa, are almost inexistent.ConclusionsWe argue that population epidemiology surveys with ultrasound are warranted in Sahelian countries, including Niger. These studies could improve the knowledge of CE epidemiology, provide health authorities with important information for public health interventions targeting this zoonosis, and shed light on any difference between tissue tropism and clinical manifestations caused by the different E. granulosus strains.

Molecular identification of Echinococcus granulosus strain in stray dogs from Northeastern Iran.

Canine echinococcosis, caused by the adult form of taeniid cestodes of the genus Echinococcus is zoonotic and has an epidemiologically worldwide distribution. Dogs infected with E. granulosus are the main source of human hydatidosis, however, there is little information on molecular epidemiology of adult Echinococcus spp. in stray dogs. In the present study, 100 stray dogs (48 males and 52 females, 72 adults and 28 juveniles) were collected from Khorasan Razavi province in Northeastern Iran during October 2013 to December 2014. Thirty-eight (21 males and 17 females, 3 juveniles and 35 adults) out of 100 dogs were infected with E. granulosus. There were no significant differences in prevalence observed between females (43.5%) and males (34.4%), however, the prevalence of E. granulosus, showed a significant increasing trend with increasing host age (p<0.05). Thirty-eight isolated parasites from 38 stray dogs (one parasite per dog) were used for PCR-RFLP analysis of the ITS1 gene. PCR-RFLP analysis showed that all the 38 parasites were E. granulosus G1 genotype (common sheep strain). Five PCR products were sent for sequencing. The results of sequencing were similar to those reported by PCR-RFLP analysis and the presence of E. granulosus G1 genotype (sheep strain) as dominant genotype in dogs were emphasized. The results of this study suggest that the sheep strain occurs in definitive host in Northeastern Iran. Data presented here are expected to be useful for health and educational authorities responsible for designing and implementing effective measures for disease control.

Identification of Echinococcus granulosus strains using polymerase chain reaction-restriction fragment length polymorphism amongst livestock in Moroto district, Uganda.

A descriptive study was conducted to identify the different strains of Echinococcus granulosus occurring in livestock in Moroto district, Uganda. Echinococcus cysts from 104 domestic animals, including cattle, sheep, goats and camels, were taken and examined by microscopy, polymerase chain reaction with restriction fragment length polymorphism and Sanger DNA sequencing. Echinococcus granulosus genotypes or strains were identified through use of Bioinformatics tools: BioEdit, BLAST and MEGA6. The major finding of this study was the existence of a limited number of E. granulosus genotypes from cattle, goats, sheep and camels. The most predominant genotype was G1 (96.05%), corresponding to the common sheep strain. To a limited extent (3.95%), the study revealed the existence of Echinococcus canadensis G6/7 in three (n = 3) of the E. granulosus–positive samples. No other strains of E. granulosus were identified. It was concluded that the common sheep strain of Echinococcus sensu stricto and G6/7 of E. canadensis were responsible for echinococcal disease in Moroto district, Uganda.

Studies on the Protoscoleces and Hooks of Echinococcus Granulosus from Libya by Scanning Electron Microscope

Introduction: Protoscolex and hook morphology had been used to identify different strains of Echinococcus granulosus. Method: In the present study, hydatid sand was isolated from infected organs such as liver, lung and spleen from slaughtered animals in several abattoirs in the selected study areas in Libya. Scanning Electron Microscope (SEM) was used to describe the outer surface of the Protoscoleces and the hooks. Result: SEM pictures showed different morphological characters of the outer surface of the different parts of the same protoscolex. Also, the buds on the outer surface of brood capsule, and showed some differences between the large and small hooks. These findings appeared the that there was a correlation with significant statistical difference between the measurements of large as well as small hooks from the same organs of each host as well as between different hosts. Conclusion: Finally, it was difficult to determine whether these cases are not real distortions in the morphology of E. granulosus. They possibly could be caused by mutation or related to a special strain of E.granulosus. Thus, the findings of the present study would suggest that there is a need to consider relationships between the different characters of hooks with different strains of E.granulosus.

A Revisit to the Infamous Zoonotic Echinococcosis: A Molecular Review

Through the past five decades, significant phenotypic and genetic variabilities have been recognized and identified in various strains of Echinococcus granulosus isolated from different regions. Studies have revealed that the different strains of E. granulosus consist of heterogenous groups of genetic variants, which may display variations in morphology, host specificity, development rate, pathogenicity and geographical distributions. Thus identification of strain types is very important in strategizing and implementing an Echinococcus control and management program.

Morphometric differentiation between camel and sheep strains of Echinococcus granulosus using computer image analysis system (CIAS)

Objective To find importance of morphometric criterion of larval rostellar hook of Echinococcus granulosus (E. granulosus) and the easy and reliable method for distinguish sheep and camel strains in epidemiologic studies. Methods Larval rostellar hooks ( n=1860) of 31 camel and sheep isolates in Iran, which already had been characterized by PCR, were carefully processed by computerized imagime analysis system (CIAS) and acquired data about rostellar hooks were analyzed using software SPSS. Results Measurement analysis of rostellar hooks [mean length (24.23±3.12) μ m] indicated that length of the large hook was a remarkable parameter for strain differentiation. Data analysis demonstrated that CIAS could be used as a reliable tool to distinguish camel from sheep strains with high sensitivity (95.2%) and specificity (91.5%). Conclusions CIAS as a specific, sensitive, economic, fast, and reliable means might be used for differentiation of E. granulosus strains. Although perimeter and area were measured by digital technology, they were not shown as discriminative criterion as total hook length did.

Molecular epidemiology of Echinococcosis from food producing animals in north India

Echinococcosis is an important medical, veterinary and economic concern in India. Ten cysts were randomly selected from each intermediate host species (cattle, buffalo, sheep, goat and pigs). Either the germinal layer (sterile cysts) or protoscoleces (fertile cysts) were collected for molecular characterization. A 434 base pair fragment of the mitochondrial cytochrome oxidase-1 gene was amplified using PCR from each isolate. Ten representative samples (2 from each intermediate host species) were sequenced in both the directions from which readable sequences were obtained from nine for phylogenetic analysis (NCBI, Blast). Phylogenetic analysis of cytochrome oxidase I gene revealed that seven (77.7%) isolates, from cattle (2), pigs (2), buffaloes (1) and goat (2) were clustered with the Indian Buffalo (G3) strain of Echinococcus granulosus, while two (22.2%) isolates from sheep were clustered with the sheep strain (G1) of E. granulosus. Phylogenetic analysis of the cytochrome oxidase-1 gene revealed that the buffalo strain (G3) and common sheep strain (G1) are cycling among livestock in north India and that these strains are highly adapted to cattle, buffalo, sheep, goats and pigs.

Immunological aspects of cystic echinococcosis in Erbil

Background and objectives: Echinococcus granulosus exists as a complex of different strains that differ in a wide variety of criteria that impact on the epidemiology, immunology, pathology and control of hydatid disease. This study was undertaken to investigate both humoral and cellular immune responses that are developed against hydatid cysts in Erbil. Methods: Thirty patients (9 males and 21 female) with surgically confirmed cystic echinococcosis and 10 apparently healthy individuals were included in this study. IgG ELISA was performed to asses humoral immune responses. CD4/ CD8 ratio, eosinophil count and lymphocyte transformation response were done to asses the cellular immune responses. The level of IFN-γ and TNF-α was also assayed. Results: The sensitivity of ELISA to detect anti-hydatid antibodies was shown to be 83.33%. CD4 / CD8 ratio was significantly (P&lt; 0.001) decreased in patients with cystic echinococcosis as compared to normal control group, while eosinophil count (P&lt; 0.001), lymphocyte transformation response (P&lt; 0.001) and IFN-γ level (P&lt; 0.01) were significantly increased. In contrast the level of TNFα was non- significantly changed in echinococcosis patients. Conclusion: The current study showed that the local strain of Echinococcus granulosus induces both cellular and humoral immune responses, and the number of peripheral blood CD8 T cells was significantly increased in cystic echinococcosis patients. However, hyporesponsivness to hydatid specific antigens has not been induced.

Old problems on a new playing field: Helminth zoonoses transmitted among dogs, wildlife, and people in a changing northern climate

Although surveillance is limited, indigenous residents at latitudes ranging from 53 to 73°N in Canada appear to have a higher occurrence of infection with some zoonotic parasites than the general population. Conversely, they are relatively naïve to other zoonotic parasites that have previously been unable to establish at northern latitudes. For those parasites that circulate among dogs, wildlife, and people, potential risk factors in the North include limited availability of veterinary services, presence of free-roaming dog populations, and consumption of locally harvested fish and wildlife. These regions are also experiencing some of the greatest impacts of climate change in North America, including increased temperature, precipitation, and frequency and severity of extreme weather. We review the current taxonomy, genetic diversity, host and geographic distributions, epidemiology and risk factors for 3 genera of helminths (Diphyllobothrium spp., Echinococcus spp., and Toxocara sp.) in Canada's North in order to identify climate-sensitive aspects of their ecology. Free-living stages of parasitic zoonoses endemic in the Arctic (such as Diphyllobothrium dendriticum, the cervid strain of Echinococcus granulosus, and Arctic strains of Echinococcus multilocularis) will experience trade-offs between enhanced survival under wetter conditions and increased mortality under warmer conditions. Climate change might also lead to the introduction and establishment in the Arctic of parasitic zoonoses previously restricted to the sub-Arctic, such as Diphyllobothrium latum, Toxocara canis, and the prairie strain of E. multilocularis. Molecular techniques applied in broad geographic surveys are needed to address critical knowledge gaps in the geographic distribution, genetic diversity, and public health significance of zoonotic helminths already in the circumpolar North, and to determine the current barriers to range expansion of temperate-adapted parasites into the North. Dogs will continue to play important roles in the North, including that of a “bridging” host between sylvatic cycles and human communities. In a warming north, increased opportunities for business, agriculture, and tourism favor importation of dogs and their parasites into a newly suitable environment. Collaborations among veterinarians, public health personnel, and policy-makers are needed to enhance surveillance and mitigate for dog-transmitted parasitic zoonoses in a changing North.

Apparent dominance of the G1–G3 genetic cluster of Echinococcus granulosus strains in the central inland region of Portugal

Infection by the larval stage of the cestode Echinococcus granulosus causes a disease known as cystic echinococcosis or hydatidosis, which is one of the most widespread zoonotic infections of veterinary and medical importance. Numerous studies have shown that E. granulosus exists as a complex of strains differing in a wide variety of criteria. Ten distinct genotypes (G1–G10) have been identified with a potential impact on the pathology, epidemiology and the effect of the measures implemented for the control of hydatidosis. Our main objective was to carry out a preliminary analysis of the genotypes of E. granulosus circulating in the central inland region of Portugal. Parasite samples (hydatid cysts, n = 27) were isolated from the liver and lung of sheep and cattle. The DNA extracted from protoscoleces isolated from the fertile cysts served as a template for the PCR amplification of the part of the mitochondrial cytochrome c oxidase subunit 1 ( cox1), ATP synthase F0 subunit 6 ( atp6) as well as the large ( rrnL/16 S) and small ( rrnS/12 S) ribosomal RNA genes. Similarity searches with homologous sequences in the databanks indicated a very high similarity with references assigned to the G1, G3 and/or G1–G3 complex of Echinococcus strains. Phylogenetic analysis (Bayesian approach) supported these observations, and confirmed the assignment of all the analyzed sequences to the G1–G3 genetic cluster.

Influence of selection pressure on mitochondrial genes of Taenia solium, T. hydatigena and T. taeniaeformis of Indian origin

The mitochondrial genotyping was done in Taenia solium, of porcine origin, T. hydatigena of caprine origin and T. taeniaeformis isolated from black rats (Rattus rattus). By comparison of punctuation codons of ATP dehydrogenase subunit6 (atp6), Indian Taenia species could not be differentiated from common sheep strain of Echinococcus granulosus. But T. solium isolated from non descriptive black pigs could be clustered into Asian isolate by partial fragment of cytochrome oxidase subunitI (coxI) while conservative substitution was seen only at one position. Comparison of sequence of NADH dehydrogenase subunitI (nadhI), the same Indian isolates was also indistinguishable from Asian isolates as described earlier. Based upon synonymous and non synonymous substitution, T. taeniaeformis of Rattus rattus origin could be differentiated from T. taeniaeformis of Apodermus sylvaticus origin. This type of change was discussed in terms of positive selection for antigen coding gene and also for eukaryotes residing in different climates.

Using mitochondrial and nuclear markers to evaluate the degree of genetic cohesion among Echinococcus populations

Based on the distinctiveness of their mitochondrial haplotypes and other biological features, several recent publications have proposed that some Echinococcus granulosus strains should be regarded as separate species. However, the genetic cohesion of these species has not been extensively evaluated using nuclear markers. We assess the degree of polymorphism of the partial mitochondrial cox1 (366 bp), the nuclear mdh (214 bp) and EgAgB4 (281–283 bp) genes of E. granulosus sensu lato isolates collected from areas where different strains occur sympatrically. Five distinct mitochondrial haplotypes were determined by direct sequencing (G1, G2, G5, G6 and G7). The mdh genotypes were first screened by SSCP: three alleles were identified (Md1–Md3), which were further confirmed by nucleotide sequencing. For EgAgB4, which was analysed by direct sequencing the PCR products, two groups of sequences were found: EgAgB4-1 and EgAgB4-2. No haplotype-specific mdh or EgAgB4 sequences occur. Nevertheless, alleles Md1 and Md2 and type 1 sequences of EgAgB4 showed a higher frequency within the group of haplotypes G1–G2, while allele Md3 and EgAgB4-2 are most frequent in the G5–G7 cluster. By AMOVA it is shown that 79% of the total genetic variability is found among haplotype groups. These findings are compatible with two not mutually exclusive evolutionary hypotheses: (a) that haplotypes share an ancestral polymorphism, or (b) that the reproductive isolation between parasites with distinct haplotypes is not complete, leading to gene introgression. The biologic and epidemiologic consequences of our findings are discussed.

Heterogeneous distribution of human cystic echinococcosis after a long-term control program in Neuquén, Patagonia Argentina

The present study is the first comprehensive analysis of human cystic echinococcosis (CE) epidemiological data carried out in the province of Neuquén, Patagonia Argentina, after 34 years of uninterrupted control program. A retrospective study of all the official records of confirmed human CE cases between 1995 and 2004 was carried out. A total of 1107 cases were reported. The overall mean annual incidence (MAI) was 24.4 per 100,000 inhabitants for the total population and 9.7/100,000 in the 0–14 year group. Distribution of cases by age and sex as well as frequency of cyst locations was analysed. Children accounted for 13.3% of total cases, indicating active transmission of the disease. Territorial distribution of cases was highly heterogeneous: MAI per 100,000 ranged from 7.9 in the Metropolitan Sanitary Area to 78.4 in the western rural areas. Higher values were recorded in small communities as Pilo Lil (800/100,000). MAI showed a significant decrease from 1995 to 1999 (43.9–18.8) but remains stable from 2000 to 2004 (15.9–15.5). These results suggest that standard control measures, despite long-term implementation, are not able to produce a sustained improvement of the epidemiological status of the disease. Further studies about local transmission cycles, definite and intermediate hosts present, Echinococcus granulosus strains or cultural behaviours in small communities are required in order to adequate the control actions in Neuquén.

Taxonomic position and geographical distribution of the common sheep G1 and camel G6 strains of Echinococcus granulosus in three African countries

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.