Ubenimex combined with Albendazole for the treatment of Echinococcus multilocularis-induced alveolar echinococcosis in mice

Introduction

Alveolar echinococcosis (AE) is a parasitic disease caused by E. multilocularis metacestodes and it is highly prevalent in the northern hemisphere. We have previously found that vaccination with E. multilocularis-Leucine aminopeptidase (EM-LAP) could inhibit the growth and invasion of E. multilocularis in host liver, and Ubenimex, a broad-spectrum inhibitor of LAP, could also inhibit E. multilocularis invasion but had a limited effect on the growth and development of E. multilocularis.

Methods

In this study, the therapeutic effect of Ubenimex combined with Albendazole on AE was evaluated. Mice were intraperitoneally injected with protoscoleces and imaging examination was performed at week 8 and week 16 to detect cyst change. During this period, mice were intraperitoneally injected with Ubenimex and intragastrically administered with Albendazole suspension. At last, the therapeutic effect was evaluated by morphological and pathological examination and liver function.

Results

The results revealed that the combined treatment could inhibit the growth and infiltration of cysts in BALB/c mice infected with E. multilocularis protoscoleces. The weight, number, invasion and fibrosis of cysts were reduced in mice treated with Ubenimex in combination with Albendazole. The same effect was achieved by the single Ubenimex treatment because of its inhibitory effect on LAP activity, but it was less effective in inhibiting the growth of cysts. The levels of ALT, AST, TBIL, DBIL, ALP, and γ-GT were reduced after the combined treatment, indicating that treatment with both Ubenimex and Albendazole could alleviate liver damage.

Discussion

This study suggests that the combined treatment with Ubenimex and Albendazole could be a potential therapeutic strategy for E. multilocularis infections.

Past and Present of Diagnosis of Echinococcosis: A Review (1999-2021)

The larval forms of taeniid cestodes belonging to the genus Echinococcus are the source of the zoonotic infection known as echinococcosis. Alveolar and cystic echinococcosis are caused by Echinococcus multilocularis and Echinococcus granulosus (s. s) respectively. It is endemic in several regions of the world. In this systematic review, we describe diagnosis, and the species (human, canids, livestock, and small rodents) affected by cystic (CE) and alveolar echinococcosis (AE). From 1999 to 2021, we searched the online directory through PubMed, SCOPUS, Web of Science, and google scholar. Among the 37,700 records found in the online databases, 187 publications met our eligibility requirements. The majority of investigations employed a range of diagnostic methods, such as ELISA, imaging, copro-PCR, necropsy or arecoline hydrobromide purgation, morphological cestode confirmation, and fecal sieving/flotation to detect and confirm Echinococcus infection. ELISA was the most commonly used method followed by PCR, and imaging. The research team retrieved data describing the incidence or assessment of the diagnostic test for E. multilocularis in humans (N = 99), canids (N = 63), small ruminants (N = 13), large ruminants (N= 3), camel (N= 2), pigs (N=2) and small mammals (N= 5). This study was conducted to explore the diagnostic tools applied to detect echinococcosis in humans as well as animals in prevalent countries, and to report the characteristic of new diagnostic tests for disease surveillance. This systematic review revealed that ELISA (alone or in combination) was the most common method used for disease diagnosis and diagnostic efficacy and prevalence rate increased when recombinant antigens were used. It is highly recommended to use combination protcols such as serological with molecular and imaging technique to diagnose disease. Our study identified scarcity of data of reporting echinococcosis in humans/ animals in low-income or developing countries particularly central Asian countries. Study reports in small rodents indicate their role in disease dissemination but real situation in these host is not refected due to limited number of studies. Even though echinococcosis affects both public health and the domestic animal sector, therefore, it is important to devise new and strengthe implementation of the existing monitoring, judging, and control measures in this estimate.

Low genetic variation in Echinococcus multilocularis from the Western Sichuan Plateau of China revealed by microsatellite and mitochondrial DNA markers

The prevalence of E. multilocularis is a major public health problem in China. To better understand the molecular epidemiology and evolutionary patterns of E. multilocularis, an adequate dataset regarding the genetic variance of this parasite is necessary. However, for now, available genetic data of E. multilocularis is still insufficient. In the study, the EmsB microsatellite and the partial mitochondrial cox1 gene were combined to investigate the genetic diversity of 64 E. multilocularis samples from human, dogs and voles. These samples were collected in the Western Sichuan Plateau, where the highest village-based human prevalence of alveolar echinococcosis was recorded worldwide. The aim of the study is to gather more informative genetic data of E. multilocularis in the areas, especially those obtained using the EmsB marker. The microsatellite analysis revealed 7 different EmsB profiles, 1 of which was found in 90.63% of the total samples collected from all 3 hosts. This major profile was identical to the one detected in the same area 16 years ago. The rest of the 6 profiles, each represented by only 1 isolate, did not correspond to any of the profiles previously reported. All the profiles detected in the study belonged to the Asian cluster. Meanwhile, according to sequence analysis of the 758 bp cox1 region, 4 haplotypes all assigned to the Asian clade were detected among the isolates. A star-like haplotype network was exhibited with a centrally positioned haplotype found in 93.75% of the samples. The overall haplotype and nucleotide diversities were both low. These findings provided evidence for a founder event or bottleneck and subsequent population expansion in E. multilocularis. The EmsB profiles were not fully consistent with the cox1 haplotypes. The same correspondence relationship was mainly observed in samples with the major profile P5 and the main haplotype EmHa1. A total of 54 isolates assigned to profile P5 were classified to the EmHa1 haplotype. In conclusion, both the microsatellite and mtDNA markers showed low variability within the Tibetan population of E. multilocularis. An EmsB profile and a cox1 haplotype were found to be predominant in the study area, which appears to remain steady for over a decade. The results reinforce the higher potential of the microsatellite DNA marker with high discriminative power to identify the very low genetic polymorphism of E. multilocularis than that of the partial cox1 sequencing. The data obtained in the study would be helpful to enlarge the data pool to further probe the possible origins and dispersal of E. multilocularis in China.

The situation of echinococcosis in stray dogs in Turkey: the first finding of Echinococcus multilocularis and Echinococcus ortleppi

Echinococcosis, caused by larval stage of the genus Echinococcus, is one of the most important zoonotic diseases worldwide. The purpose of this study was to determine the presence and prevalence of Echinococcus species in stray dogs of Erzurum, a highly endemic region for cystic echinococcosis (CE) and alveolar echinococcosis (AE) in Turkey. The study samples consisted of 446 stray dog faecal specimens collected from an animal shelter in Erzurum, Turkey, between October 2015 and February 2016. The faecal samples were collected from individual dogs for the isolation of taeniid eggs using the sequential sieving and flotation method (SSFM). Molecular analyses and sequencing revealed the prevalence of Echinococcus spp. as 14.13% (63/446) in faecal samples. The stray dogs harboured five different Echinococcus spp.: E. granulosus s.s. (G1/G3) (n = 41), E. equinus (G4) (n = 3), E. ortleppi (G5) (n = 1), E. canadensis (G6/G7) (n = 3) and E. multilocularis (n = 16). E. granulosus s.s. was the most abundant species. Surprisingly, the occurrence of E. multilocularis in dogs was revealed for the first time in Turkey. E. ortleppi was also reported for the first time in Turkey. These findings highlight a significant public health risk for human AE and CE, presenting useful baseline data on Echinococcus spp. infection in dogs for designing control strategies.

multilocularis from the Punjab Province of Pakistan using sequence analysis

BACKGROUND

Echinococcosis is a zoonotic parasitic disease causing serious health problems in both humans and animals in different endemic regions across the world. There are two different forms of human echinococcosis: Cystic Echinococcosis (CE) and Alveolar Echinococcosis (AE). CE is caused by the larval stage of Echinococcus granulosus sensu lato and AE by the larval stage of Echinococcus multilocularis. Geographically, CE is universally distributed, while AE is prevalent in the northern hemisphere. Although the disease is endemic in neighboring countries (China, Iran and India) of Pakistan, there are limited reports from that country. Besides, there are no comprehensive data on the genotyping of Echinococcus species in humans based on sequence analysis. This study aimed to detect the presence of human CE and to identify Echinococcus spp. in human isolates through genetic characterization of hydatid cysts in the Punjab Province of Pakistan.

METHODS

Genetic analysis was performed on 38 human hydatid cyst samples collected from patients with echinococcosis using mitochondrial cytochrome c oxidase subunit 1 (cox1), cytochrome b (cytb) and NADH subunit 1 (nad1). Patient data including age, epidemiological history, sex, and location were obtained from hospital records.

RESULTS

According to the sequence analysis we detected E. granulosus sensu stricto (n = 35), E. canadensis (G6/G7) (n = 2), and E. multilocularis (n = 1). Thus, the majority of the patients (92.1%, 35/38) were infected with E. granulosus s.s. This is the first molecular confirmation of E. canadensis (G6/G7) and E. multilocularis in human subjects from Pakistan.

CONCLUSIONS

These findings suggested that E. granulosus s.s. is the dominant species in humans in Pakistan. In addition, E. canadensis (G6/G7) and E. multilocularis are circulating in the country. Further studies are required to explore the genetic diversity in both humans and livestock.

Editorial overview: From farms and forests to forks? A review of diagnosis and management of globally important zoonotic Echinococcus spp. cestodes

This FAWPAR Special Issue is dedicated to zoonotic Echinococcus species. It is a compilation of invited papers that spans important aspects from molecular markers of emergence, diagnostics in both definitive and intermediate hosts, treatment of human alveolar echinococcosis, to control strategies in definitive hosts.

Survey of echinococcoses in southeastern Qinghai Province, China, and serodiagnostic insights of recombinant Echinococcus granulosus antigen B isoforms

Background

Echinococcoses, caused by metacestodes of Echinococcus granulosus (cystic echinococcosis; CE) and E. multilocularis (alveolar echinococcosis; AE), represent major emerging parasitic diseases. These enzootic helminthiases invoke significant public health concerns and social burdens in endemic areas. The diseases are prevalent in the Qinghai-Tibetan Plateau, China, while community-based epidemiological studies have been scarcely reported. We surveyed echinococcosis patients in the southeastern Qinghai Province, China, to better understand the concurrent epidemiological situation in this area.

Methods

During July and August of 2013 and 2014, we screened echinococcosis patients at Yushu and Golog Prefectures, Qinghai Province, China, in a diagnostic campaign. A total of 2856 people (male:female ratio, 1:1.12; mean age, 34.6 years; age range, 6–88 years) were ultrasonographically examined for the presence of hepatic echinococcal cysts. We also collected serum samples from patients and analyzed antibody reactivity against recombinant forms of diverse E. granulosus antigen Bs (rEgAgB1-5) by enzyme-linked immunosorbent assay.

Results

We detected 134 patients whose imaging scans were compatible with CE (115 cases) and AE (20 patients). One patient might have been infected with both CE and AE. The overall incidence was 4.7% (CE, 4.0%; AE, 0.7%). A large proportion (67.5%) of CE patients was diagnosed at active and transitional CE1-CE3 stages in their late 30s. The AE cases were generally detected at advanced stage in patients at early 20s (60%). Analysis of the receiver operating characteristic curve and Youden’s index indicated that rEgAgB2 was the most promising biomarker, followed by rEgAgB3 and rEgAgB1. Overall, sensitivity and specificity of rEgAgB1-3 were 84.5–92.7% and 91.9–94.6%, respectively. rEgAgB4 and 5 showed low sensitivity with high cross-reactivity.

Conclusions

Our results strongly suggest that disability-adjusted life years related to echinococcoses in Qinghai-Tibetan areas might be more serious than previously considered. Control and prevention strategy against CE and AE are highly required in these areas. In addition to ultrasonography, serological tests might provide supportive data. However, serological data should be carefully interpreted for differential diagnosis, especially in areas where both CE and AE are co-endemic.

Electronic supplementary material

The online version of this article (10.1186/s13071-019-3569-6) contains supplementary material, which is available to authorized users.

Genetic Diversity in Echinococcus multilocularis From the Plateau Vole and Plateau Pika in Jiuzhi County, Qinghai Province, China

The Qinghai-Tibet Plateau is a highly endemic area of alveolar echinococcosis where a series of intermediate hosts, especially voles and pikas, are infected with Echinococcus multilocularis. The metacestodes of E. multilocularis are fluid-filled, asexually proliferating cysts, and they are mainly found in the host's liver in the form of tumor-like growths. In this study, we investigated the genetic variations of E. multilocularis in four mitochondrial (mt) genes, namely, NADH dehydrogenase subunit 5 (nad5), adenosine triphosphate subunit 6 (atp6), cytochrome c oxidase subunit 1 (cox1), and NADH dehydrogenase subunit 1 (nad1). The complete nad5, atp6, cox1, and nad1 genes were amplified separately from each hydatid cyst isolate using polymerase chain reaction (PCR) and then sequenced. Phylogenetic trees were then generated based on the combined mt genes using MrBayes 3.1.2 and PAUP version 4.0b10. The results showed that thirty of 102 voles and two of 49 pikas were infected with E. multilocularis. The genetic variation distances among all E. multilocularis samples were 0.1–0.4%, 0.2–0.4%, 0.1–0.6%, and 0.1–0.4% for nad5, atp6, nad1, and cox1, respectively. Compared to previous studies of the genetic diversity of E. multilocularis based on the cox1 gene, the genetic distances within the same group were 1.3–1.7% (Mongolia strain), 0.6–0.8% (North American strain), 0.3–0.6% (European strain), and 0.1–0.4% (Asian strain). Based on concatenated sequences of the nad5, atp6, cox1, and nad1 genes all haplotypes were divided into two clusters. In conclusion, the genetic diversity of E. multilocularis based on mt genes on a small local area is at low level but between different regions with long distance and different ecological environment each other, the genetic diversity is at relatively high level; genetic variation is higher in the nad1 gene than that in the other three mt genes. The results on a local scale provide basic information for further study of the molecular epidemiology, genetic differences and control of E. multilocularis in Qinghai Province, China.

Gene expression profiles of the small intestinal mucosa of dogs repeatedly infected with the cestode Echinococcus multilocularis

The data set presented in this article is related to a previous research article entitled " The timing of worm exclusion in dogs repeatedly infected with the cestode Echinococcus multilocularis" (Kouguchi et al., 2016) [1]. This article describes the genes >2-fold up- or down-regulated in the first- and repeated-infection groups compared to the healthy controls group. The gene expression profiles were generated using the Agilent-021193 Canine (V2) Gene Expression Microarray (GPL15379). The raw and normalized microarray data have been deposited with the Gene Expression Omnibus (GEO) database under accession number GSE105098.

Historical Aspects of Echinococcosis

Echinococcosis is a zoonosis whose history dates back to antiquity. This article provides an overview on the general history of echinococcosis, including the elucidation of Echinococcus life cycles and the long controversy on the aetiology of the cystic and alveolar forms of echinococcosis (CE and AE), lasting about 100years since the middle of the 19th century. Furthermore, selected historical aspects of some fields of echinococcosis research are discussed and compared with our current knowledge, such as geographic distribution and epidemiology of CE (Echinococcus granulosus) and AE (Echinococcus multilocularis), clinical aspects and pathology, diagnosis in humans and animals, treatment (with focus on chemotherapy), control and basic research. A short paragraph is devoted to the neotropical forms of echinococcosis, caused by Echinococcus vogeli and Echinococcus oligarthrus. In this context the achievements of some ancestral pioneers of echinococcosis research are particularly highlighted and appreciated. Finally, the role of associations, international organizations (World Health Organization and others) and international working groups in echinococcosis research and control is briefly outlined. The retrospective reveals both the admirable achievements of our ancestors and the scientific progress of more recent times. But, it also shows the gaps in our knowledge, skills and resources that we need to control or even eradicate echinococcosis.

Genetic diversity in Echinococcus shiquicus from the plateau pika (Ochotona curzoniae) in Darlag County, Qinghai, China

The metacestode of Echinococcus shiquicus has been recorded previously in the lung and liver of its intermediate host, the plateau pika (Ochotona curzoniae), but there is limited information regarding other organ sites. There is also limited evidence of intra-specific genetic variation within E. shiquicus. A PCR-amplified mitochondrial (mt) nad1 gene fragment (approximately 1400bp in size), with unique EcoRI and SspI restriction sites, was used to distinguish cysts or cyst-like lesions of E. shiquicus from E. multilocularis. Then, the complete mt nad1 and cox1 genes for the E. shiquicus isolates were amplified and sequenced. Phylogenetic tree and haplotype network analyses for the isolates were then generated based on a concatenated dataset of the nad1 and cox1 genes using the neighbour-joining (NJ) method and TCS1.21 software. Nineteen of eighty trapped pikas were found to harbor cysts (71 in total) when dissected at the survey site. Seventeen animals had cysts (fertile) present only in the lungs, one animal had fertile cysts in the lungs and spleen, and one individual had an infertile kidney cyst. Restriction endonuclease analysis of a fragment of the nad1 gene indicated all the cysts were due to E. shiquicus. Genetic diversity analysis revealed that the nad1 and cox1 genes varied by 0.1-1.2% and 0.1-1.0%, respectively. Haplotype network analysis of the concatenated nad1 and cox1 sequences of the isolates showed they were classified into at least 6 haplotypes, and different haplotype percentages ranged from 4.2% to 29.6%. Although, high haplotype diversity was evident in the study area, the complete nad1 and cox1 gene sequences obtained indicated that all samples represented isolates of E. shiquicus. The study has also provided a new PCR-restriction endonuclease-based method to rapidly distinguish E. shiquicus from E. multilocularis which provides a useful tool for epidemiological investigations where the two species overlap.

multilocularis in young cats

Two single-site, laboratory, negatively controlled, masked, randomised dose confirmation studies were performed: one in dogs, the other in cats. After a period of acclimatisation, both the dogs and cats were orally infected with Echinococcus multilocularis protoscoleces. In the dog study, 10 dogs received a single dose of Milpro® tablets at a minimum dose of 0.5 mg/kg milbemycin oxime and 5 mg/kg praziquantel 18 days post-infection and 10 dogs received no treatment. In the cat study, 10 cats received a single dose of Milpro® tablets at a minimum dose of 2 mg/kg milbemycin oxime and 5 mg/kg praziquantel 7 days post-infection, 10 cats received a single dose of the treatment 18 days post-infection and 10 cats remained untreated. In both studies, intestinal worm counts were performed 23 days post-infection at necropsy. No worms were retrieved from any of the 30 treated animals. Nine of 10 control dogs had multiple worms (geometric mean 91, arithmetic mean 304) and all 10 control cats had multiple worms (geometric mean 216, arithmetic mean 481). The difference in worm counts between all three treated groups and their controls was highly significant (ANOVA p values of log transformed data <0.0001). Efficacy of 100 % was demonstrated for the elimination of adult E. multilocularis in dogs and cats as well as for elimination of immature E. multilocularis in cats as evidenced by the effectiveness of treatment 7 days post-infection. The treatments were well accepted and tolerated, and there were no adverse drug reactions observed.