Survey of helminths in adult sheep in Heilongjiang Province, People's Republic of China

Gastrointestinal parasites of the wild ungulates (Mammalia: Cetartiodactyla) in the Hemis National Park, Ladakh, India

We evaluated the gastrointestinal parasitic prevalence and intensity of wild ungulates in the Hemis National Park of Ladakh by examining their fresh faecal samples. A total of 327 fresh faecal samples from three wild ungulates, blue sheep Pseudois nayaur (n = 127), Ladakh urial Ovis vignei vignei (n = 110), and Himalayan ibex Ibex siberica (n = 90) were collected between June 2021 and May 2022. The techniques of flotation and sedimentation were used to find parasite eggs and oocysts from the faecal samples. Out of 327 samples examined, 165 samples were infected with gastrointestinal parasites making an overall prevalence of 50.45%. Seven parasitic taxa, including one protozoan (Eimeria spp.), five nematodes (Nematodirus spp., Strongyloides spp., Haemonchus sp., Trichuris sp., and Trichostrongylus spp.), and one cestode (Monezia spp.), were found during the current investigation. Mixed infection was reported in 36 (11%) of the total examined samples. The prevalence of gastrointestinal parasites was found to be highest in blue sheep (55.11%), followed by Ladakh urial (49.09%) and Himalayan ibex (45.55%). The highest prevalence was recorded in the summer (64.42%), and the lowest in the winter (33.82%). A significant difference in parasitic prevalence was observed across seasons in each of the three wild ungulate hosts. However, there was no significant difference in the prevalence of parasites between these hosts.

Prevalence and molecular identification of gastrointestinal nematodes in Qinghai-Tibetan Plateau of China

BACKGROUND

Gastrointestinal nematodes (GINs) have seriously affected the production and earnings of animal husbandry in various countries, while some species of GINs infect humans. At present, little is known about the species and prevalence of GINs in Qinghai-Tibetan Plateau (QTP).

METHODS

In this study, 528 fresh faecal samples were collected from typical areas in different altitudes with seven species of livestock in Qinghai, Tibet, Gansu and Yunnan Provinces. ITS-2 rRNA gene of nematodes was employed to detect by PCR and sequencing analysis. Phylogenetic analysis of related sequences was performed using MEGA 6.0 software.

RESULTS

The overall prevalence of GINs was 80.3% with 20 species of GINs detected, while Teladorsagia circumcincta was the dominant one, and four of which were zoonotic species such as Trichostrongylus colubriformis, Trichostrongylus axei, Trichostrongylus vitrinus and Oesophagostomum stephanostomum.

CONCLUSION

The study provided panoptic information on the prevalence and species diversity of GINs in QTP area, which is useful and valuable for reference of measure formulation in livestock husbandry and public health concerns. The parasites of T. circumcincta, Cylicocyclus nassatus, Strongylus edentatus, Cylicostephanus longibursatus, Telephlebia brevicauda, Cyathostomum catinatum, Mecistocirrus digitatus, Cooperia punctata, Cylicodontophorus bicoronatus, Nematodirus oiratianus and Oesophagostomum asperum were firstly reported the presence in QTP area. The study also showed that horse could be infected by T. circumcincta, goat could be infected by C. nassatus, cattle could be infected by S. edentatus and C. bicoronatus,and O. stephanostomum could infect yak, cattle and Mongolian sheep in worldwide. Nevertheless, more investigations are needed, such as microscopic examination, to accurately determine the species in the region.

Inflicting Significant Losses in Slaughtered Animals: Exposing the Hidden Effects of Parasitic Infections

We started a campaign in the heart of Faisalabad, Punjab, Pakistan, to expose the hidden threats of parasitic illnesses in ruminants and the severe financial consequences associated with them. Our in-depth investigations focused on the prevalence, impact, and astounding financial losses brought on by organ contamination in slaughtered animals. Of the 384 slaughtered ruminants examined for gastrointestinal parasites, a prevalence of 44.79% was recorded. It is interesting to note that we found no conclusive association between parasitic infection and the various ruminant species under study (p > 0.05). However, goats (52.0%) had the highest numerical prevalence of parasitic infection, followed by cattle (46.1%), buffalo (46.0%), and sheep (34.7%) in that order. A significant finding (p < 0.05) showed that the majority of animals had light parasitism (46.5%), as opposed to those with moderate (30.2%) or severe loads (23.2%). Our research revealed substantial (p < 0.05) relationships between ruminant age, sex, and parasitic infection prevalence. In comparison to females (56.4%) and adults (48.1%), males (36.1%) and young (36.9%) ruminants showed considerably decreased infection rates (p < 0.05). On the other hand, we discovered a non-significant (p > 0.05) association between the months and the prevalence of parasitic infection. As a result of the condemnation of contaminated organs such as the rumen, lungs, and liver, an estimated financial loss of PKR 133,731,400 (USD = 466,939.2) was incurred. The yearly economic losses caused by liver condemnation were much greater than those caused by rumen and lung condemnation (p < 0.05). Our research not only reported a significantly higher abundance but also economic threats of the parasitic diseases among the slaughtered animals in Faisalabad, Punjab, Pakistan. Our findings highlighted the critical need for preventive and therapeutic interventions for parasitic infections in animals, in order to mitigate the economic losses through strengthened animal health.

Assessment of antioxidant enzymes during the development of the digenetic trematode parasite Gastrothylax crumenifer, infecting the rumen of Indian water buffalo, Bubalus bubalis

The presence of antioxidant enzymes in helminth parasites is well known. These enzymes help the parasites to survive in their hosts by detoxifying host-generated reactive oxygen species (ROS). The literature survey reveals that most of the studies related to antioxidant enzymes in helminth parasites are restricted to the adult stage while the larval stages are neglected. The present investigation is designed to evaluate the level of antioxidant enzymes in the adult and larval stages of rumen-infecting paramphistome parasites, Gastrothylax crumenifer. The larval stages include 0-day eggs, 4-day eggs, and eggs containing mature miracidia, cercariae, and metacercariae. Antioxidant enzyme assays were performed using standard assay protocols. Our findings revealed an increasing pattern in the level of Glutathione-S-Transferase (GST), Superoxide Dismutase (SOD), Glutathione Reductase (GR), and Glutathione Peroxidase (GPx) antioxidant enzymes during the development from 0-day eggs to the adult stage. Overall analysis shows that adult worms have higher antioxidant enzyme activity as compared to the larval stages, indicating that adult flukes are more adapted to oxidative stress. It can be concluded that the miracidia, cercarial, and metacercarial developmental stages of G. crumenifer possess a considerable level of antioxidant enzymes suitable to overcome the oxidative stress encountered during the development and help them in the completion of the life cycle and survival in the definitive host.

Survey of Dicrocoelium dendriticum infection in imported Romani and local sheep (Ovis aries), and potential epidemiological role in Saudi Arabia

The epidemiology of parasite infection in local and imported breeds is quite an essential topic in the meat industry and human health. This study aims to determine the prevalence of Dicrocoelium dendriticum in local sheep breeds (Naemi, Najdi, and Harri) and imported breeds from Romania (Romani breed) and the epidemiology of the infection in Saudi Arabia. Morphological description, the relationship between dicrocoeliasis and sex, age, and histological changes were also presented. A total of 6845 slaughtered sheep at Riyadh Automated slaughterhouse were investigated and followed up for 4 months between 2020-2021. It included 4,680 local breeds and 2,165 imported Romanian breeds. Fecal samples and livers and gallbladders from slaughtered animals were examined for apparent pathological lesions. The results indicated that the infection rate in slaughtered animals was 10.6% in imported Romani sheep and 0.9% in the local Naeimi breed. After identifying the parasite morphologically, negative results were obtained from examining feces, gallbladders, and livers of Najdi and Harry sheep breeds. The mean number of eggs per 20 µL/gallbladder was low (72.78 ± 17.8: 76.11 ± 5.07), medium (334.59 ± 90.6: 292.91 ± 26.63), and high (1113.2 ± 22.3: 1004 ± 143.4) in imported and Naeime sheep, respectively. Significant differences were found between gender and age (males and females were 3.67% and 6.31%; > 2 years 4.39%, 1-2 years 4.22%, and 1 year 3.53%) respectively. Histopathological lesions in the liver were more pronounced. Our survey confirmed the presence of D. dendriticum in imported Romani and local Naeimi sheep, and the potential role of imported sheep in the epidemiology of dicrocoeliasis in Saudi Arabia.

Pancreatic eurytrematosis in small ruminants: A forgotten disease or an untold history?

Trematodiosis are among the most neglected parasitic diseases worldwide. The pancreatic eurytrematosis (PE) is a chronic parasitic infection mostly reported in cattle but has been unnoticed in small ruminants for many decades. Our review showed PE has been recorded as scattered regional reports in goats and sheep, mainly in Asia and Eastern Europe. Eurytrema coelomaticum, Eurytrema cladorchis, and Eurytrema pancreaticum have been the main pathogenic species infecting pancreatic ducts of small ruminants. Climatic, environmental, and regional conditions in both hemispheres may support the survival and feasibility of intermediate hosts and parasitic forms, enabling the emergence and spread of PE in small ruminants. As a primarily asymptomatic condition, PE in goats and sheep flocks may also have a high prevalence, causing severe parasitic pancreatitis, production losses, and death. There is little information on anthelmintic therapeutics for PE in small ruminants, and most used anti-fluke drugs are ineffective. PE is likely more unnoticed than a neglected trematodiosis in goats and sheep, or both from a global perspective.

Molecular characteristics and genetic diversity of Fasciola hepatica from sheep in Xinjiang, China

Introduction

Fasciola hepatica is a trematode infecting ruminants worldwide and occasionally affecting other animal species, including humans. It causes significant economic losses. Geographic distribution and patterns of infection must be considered before control and management measures are developed for this parasite. DNA molecular markers are useful for the identification of flukes and elucidation of their genetic evolution. Therefore, the population structure of F. hepatica was studied using this method in sheep in Xinjiang, China.

Material and Methods

The molecular characteristics, genetic relationships within the population and dispersal patterns of F. hepatica isolates were analysed based on the cox1 and nad1 genes. The population structure of F. hepatica from three regions of Xinjiang was explored and a neutrality test was conducted.

Results

The cox1 and nad1 genes have 21 and 42 variable sites, respectively, which can be classified into 34 and 33 haplotypes. Median-joining network and phylogenetic tree analyses showed that there was no significant variation in F. hepatica isolates between the three geographical regions. Analysis of variance revealed that the genetic variation of F. hepatica was mainly present within the populations. The neutrality test indicated that the populations were relatively stable but the Hami population may have undergone short-term expansion.

Conclusion

This study revealed for the first time the molecular characteristics, genetic diversity and dispersal patterns of F. hepatica isolates from sheep in Xinjiang, thus providing new insights into the genetic variation and haplotype diversity of F. hepatica from indigenous sheep.

Analysis of internal transcribed spacer1 (ITS1) region of rDNA for genetic characterization of Paramphistomum sp

Paramphistomosis is the most prevalent disease of domestic ruminants, causing heavy economic loss in many countries across the world. The morphological identification of these parasites is difficult, therefore molecular characterization is used to discriminate Paramphistomum species. The present study was conducted to identify Paramphistomum sp. at Mardan District, Khyber Pakhtunkhwa (KPK), Pakistan. All samples of these rumen flukes were collected from buffalo. The gDNA was isolated from the adult parasites and the ITS1 region was amplified for the sequence analysis. All flukes had 100% similarity and there was no intraspecific variation. The Blast results showed that all flukes were P. cervi as they form a single cluster with P. cervi reported from China. The results of the ITS1 sequences of the present study with reference sequencing from China showed eight specific SNPs. This was the first study in which P. cervi was genetically characterized through the ITS1 region of rDNA at District Mardan, Pakistan. It can also be used as a marker for the genetic identification of Paramphistomum species.

Welfare of Native Goat Breeds in Serbia-Emphasis on Parasitological Infections

Native goat breeds in Serbia has been recognized as an important element of regional agrobiodiversity and play an important role in the safeguarding of cultural and traditional heritage. The aim of this study was to identify the main welfare issues likely to be encountered in extensive goat farming systems with an emphasis on parasitological infections. The study was conducted during the winter season on four small farms of native Balkan and Serbian white goats. For welfare assessment, animal-based indicators from AWIN protocol for goats were used. All fecal samples for parasites were qualitatively and quantitatively examined. The main welfare issues identified were poor hair coat condition (62.79%), dirty and light soiling hindquarters (31.40%), thin body condition score (26.74%), abscesses (19.78%), and udder asymmetry (18.60%). In addition, an important and prevalent welfare problem identified across all farms was parasite infection and weak significant (p < 0.001) correlation between certain parasites (Strongylidae, Moniezia spp., Buxtonella sulcate, and Protostrongylidae) and welfare indicators such as poor hair coat condition and nasal discharge. The results of this study provided the first overview and valuable insight into the impact of extensive systems on the welfare of native goats in the Balcan region.

Current Status for Controlling the Overlooked Caprine Fasciolosis

Simple Summary

Retaining sustainable agricultural systems is essential to feed the expanding population. Helminth parasite infections impact livestock production values and yields, including infections in goats, which are often overlooked. There is a requirement to collate caprine-specific knowledge surrounding fasciolosis, caused by Fasciola hepatica and Fasciola gigantica (liver flukes). Current liver fluke control methods include drug application and pasture management. This review aims to outline goat-specific fasciolosis vaccine development and the potential for alternative control methods.

Abstract

The disease fasciolosis is caused by the liver flukes Fasciola hepatica and F. gigantica, which infect a wide range of mammals and production livestock, including goats. These flatworm parasites are globally distributed and predicted to cost the livestock industry a now conservative USD 3 billion per year in treatment and lowered on-farm productivity. Infection poses a risk to animal welfare and results in lowered fertility rates and reduced production yields of meat, milk and wool. This zoonotic disease is estimated to infect over 600 million animals and up to 2.4 million humans. Current and future control is threatened with the global emergence of flukes resistant to anthelmintics. Drug resistance calls for immediate on-farm parasite management to ensure treatments are effective and re-infection rates are kept low, while a sustainable long-term control method, such as a vaccine, is being developed. Despite the recent expansion of the goat industry, particularly in developing countries, there are limited studies on goat-focused vaccine control studies and the effectiveness of drug treatments. There is a requirement to collate caprine-specific fasciolosis knowledge. This review will present the current status of liver fluke caprine infections and potential control methods for application in goat farming.

The trypsin inhibitor-like domain is required for a serine protease inhibitor of Haemonchus contortus to inhibit host coagulation

Haemonchus contortus, a blood-feeding nematode, inhibits blood coagulation at the site of infection to facilitate blood-sucking and digesting for successful parasitism. However, the mechanism underlying anti-coagulation at the host-parasite interface is largely unknown. In the current study, Hc-spi-i8, which has two greatly different transcripts named Hc-spi-i8a and Hc-spi-i8b, respectively, was described. Hc-SPI-I8A was a serine protease inhibitor containing a trypsin inhibitor-like cysteine rich (TIL) domain, while Hc-SPI-I8B was not. Hc-SPI-I8A/B were primarily expressed in the hypodermis, intestines and gonads in the parasitic stages of H. contortus. Hc-SPI-I8A interacted with Ovis aries TSP1-containing protein (OaTSP1CP), which was determined by yeast two-hybrid, co-immunoprecipitation (Co-IP), pull down and co-localization experiments. The blood clotting time contributed by the TIL domain was prolonged by Hc-SPI-I8A. Hc-SPI-I8A is most likely interfering in the extrinsic coagulation cascade by interacting with OaTSP1CP through its TIL domain and intrinsic coagulation cascade by an unknown mechanism. These findings depict a crucial point in the host-parasite interaction during H. contortus colonization, which should contribute to drug discovery and vaccine development in fighting against this important parasite worldwide.

Prevalence and risk factors associated with amphistome parasites in cattle in Iran

Amphistomiasis, a neglected trematode infection of ruminants, has recently come up as an important reason for economic losses. The aim of this study was to determine the prevalence of bovine amphistomiasis and associated risk factors such as: age, gender, breed, season, water source, pastureland and grazing system. Between January 2016 and 2017, a total of 1,000 faecal samples and 1,000 rumens of cattle were collected from slaughterhouse of Zabol, Iran ante-mortem and post-mortem, respectively, and examined. The overall prevalence was 34.6% and 19.5% in terms of amphistome adults and eggs respectively. The identified amphistome species and their prevalence were Paramphistomumcervi (13.3%), Cotylophoroncotylophorum (19.5%), Gastrothylaxcrumenifer (5.9%) and Carmyeriusspatiosus (2.7%). The correlation between prevalence and season, age, breed, water source, pastureland and grazing system was significant (p < .0001). The presented information about the prevalence of amphistomes of cattle and individual and management risk factors can be used to design appropriate control measures.

Isolation and immunoblotting of somatic antigens of Cotylophoron cotylophorum and Gastrothylax crumenifer

Paramphistomosis is the emerging fluke infection in young ruminants which results in high morbidity and mortality in tropics and sub-tropics. The present study was carried out to detect the sharing antigens among the purified somatic antigens of G. crumenifer and C. cotylophorum, in  order to use as a candidate antigen for diagnosis of paramphistomosis in sheep. Immunoblot analysis of the purified somatic antigens of C. cotylophorum and G. crumenifer using their specific rabbit hyper immune serum revealed 3 common polypeptides at the range of 27, 29 and 60 kDa. Hence these three immunodominant peptides can be used candidate antigens in development of vaccines against ovine paraphistomosis and also for early diagnosis of infection.

An ELISA based on soluble egg antigens for the serodiagnosis of animal schistosomiasis turkestanica

Background

The existing diagnostic techniques for detecting schistosomiasis turkestanica, such as aetiological assays, identify infection by parasitic worms via the incubation of miracidia from faeces or observing eggs under microscopy. However, they are limited in the diagnosis of low-grade and prepatent infections, which lead to a high misdetection rates. Therefore, a new method for parasite diagnosis with increased sensitivity is urgently needed.

Methods

Goats in Nimu County (Tibet, China) infected with Schistosoma turkestanicum in an epidemic area were selected according positivity for the infection by faecal examination. Adult worms were collected, eggs were extracted by the sodium hydroxide (NaOH) erosion method, and soluble worm antigen preparation (SWAP) and soluble egg antigen (SEA) were isolated. The best coating concentration of the antigens and the best degree of dilution for serum were determined by square array experiments, and the optimal blocking solution and serum diluents were selected. The specificity, sensitivity and crossover of the ELISA method were determined using 48 samples of goat sera positive for S. turkestanicum, 100 samples of goat sera negative for S. turkestanicum, and 54 samples of buffalo sera positive for S. japonicum. Serological assays were established with samples from goats naturally grazed in a rural area of Nimu County, Tibet Province, by using the indirect ELISA method for the diagnosis of schistosomiasis, and faeces were collected for miracidia hatching. The sensitivity of the two detection methods was compared.

Results

Eggs of S. turkestanicum were distributed in the host duodenum and small intestine. Eggs in the host intestinal wall were extracted by the NaOH erosion method, which provided intact eggs with reduced impurities. The testing results obtained by isolating SEA were more stable than those obtained by using SWAP and less affected by the coating concentration and serum dilution. Additionally, the value of positive serum/negative (P/N) serum for SEA was much higher than that for SWAP. The optimal coating concentration of SEA was 0.5 μg/ml, and the optimal serum dilution was 1:100. The specificity and sensitivity of the indirect ELISA based on SEA (S. turkestanicum) were both 100%, and no cross-reactivity was found with schistosomiasis japonica. An epidemiological survey of goats in naturally infected areas showed that the prevalence rate of schistosomiasis turkestanica was 93%, and the infection rate increased with the ages of the goats.

Conclusion

We aimed to develop a sensitive method to utilize in the mass field screening of livestock. As a diagnostic antigen, SEA (S. turkestanicum) was more suitable for serological testing than SWAP (S. turkestanicum). The indirect ELISA using SEA (S. turkestanicum) exhibited good sensitivity, specificity and no cross-reactivity with schistosomiasis japonica. The degree of infectivity and prevalence of S. turkestanicum infection in endemic areas are serious and should be a focus of concern among local departments.

A low-cost, automated parasite diagnostic system via a portable, robotic microscope and deep learning

Manual hand counting of parasites in fecal samples requires costly components and substantial expertise, limiting its use in resource-constrained settings and encouraging overuse of prophylactic medication. To address this issue, a cost-effective, automated parasite diagnostic system that does not require special sample preparation or a trained user was developed. It is composed of an inexpensive (~US$350), portable, robotic microscope that can scan over the size of an entire McMaster chamber (100 mm² ) and capture high-resolution (~1 μm lateral resolution) bright field images without need for user intervention. Fecal samples prepared using the McMaster flotation method were imaged, with the imaging region comprising the entire McMaster chamber. These images are then automatically segmented and analyzed using a trained convolution neural network (CNN) to robustly separate eggs from background debris. Simple postprocessing of the CNN output yields both egg species and egg counts. The system was validated by comparing accuracy with hand-counts by a trained operator, with excellent performance. As a further demonstration of utility, the system was used to conveniently quantify drug response over time in a single animal, showing residual disease due to Anthelmintic resistance after 2 weeks.

Microsatellite analysis reveals extensive gene flow, and lack of population structure in the farm populations of Haemonchus contortus in northern China

The parasitic nematode Haemonchus contortus is economically an important parasite of small ruminants across the globe. China is the world's largest producer, consumer, and importer of mutton. With ubiquitous distribution across the country H. contortus is one of the potential candidates to cause huge economic losses to small ruminant farming industry in China. We herein investigated genetic diversity and population structure of six farm populations of H. contortus in northern China, and also compared them to H. contortus isolates from UK and Australia. We first prepared individual DNA samples from 240 adult worms, and generated genotyping data using eight microsatellite markers. Obtained data was then subjected to allelic frequency and population genetic analyses. The overall allelic richness (mean/locus/pop = 7.375 ± 0.844-10.125 ± 1.109), and expected heterozygosity (mean/locus/pop = 0.646 ± 0.040-0.735 ± 0.025) indicated high degree of population genetic variation across the Chinese isolates. Low level of genetic differentiation (Fst = 0.010-0.066) was observed across all the populations. AMOVA results showed high level of variation (93%) within the populations. PCA analysis revealed mixed clustering of all the populations with no visible geographical sub-structuring. Finally the population admixture analysis resulted in extensive admixing of genotypes across all the populations. With these findings we conclude that there is no obvious population genetic structure with extensive gene flow across all the farm populations of H. contortus in northern China.

High prevalence of fasciolosis and evaluation of the efficacy of anthelmintics against Fasciola hepatica in buffaloes in Guangxi, China

Fasciola hepatica is a common parasite of grazing livestock in Guangxi Zhuang Autonomous Region in China, but its prevalence has not been studied. While triclabendazole is commonly used to treat F. hepatica infection in China, oxyclozanide has never been used. This study investigated the prevalence of F. hepatica infections in buffaloes in the Guangxi and evaluated the efficacy of oxyclozanide and triclabendazole as treatments. In the prevalence study, a total of 767 individual faecal samples were obtained from 58 farms in Guangxi to detect the prevalence of F. hepatica, and the total rate of infection was 87.35%. A subset of 277 infected buffaloes from these farms were randomly divided into 3 groups. Group 1 (n = 101) was treated with oxyclozanide at 10 mg/kg.bw; group 2 (n = 94) was treated with triclabendazole (12 mg/kg.bw); and group 3 (n = 82) was untreated. Faecal samples were taken on days 0, 7, 14, 21 and 28. Whole blood and serum were collected on days 0 and 14. Anthelmintic efficacy was assessed using faecal egg count reduction (FECR), buffaloes positive by coprology reduction (BPCR) as well as post-treatment improvement in biochemical and haematological indicators. After 28 days treatment, group 1 and 2 showed FECR% values above 98%, and BPCR% values of 97.03% and 77.66%, respectively. In addition, the biochemical indicators and haematological parameters were improved at 14 days post-treatment compared with those before treatment. These results indicate a high prevalence of F. hepatica in Guangxi, demonstrate that oxyclozanide and triclabendazole are effective against F. hepatica infection in buffaloes, and indicate that oxyclozanide could be used in China as an alternative drug.

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The prevalence of F. hepatica infections in 767 buffaloes was 87.35% on 58 farms from 8 districts in Guangxi Zhuang Autonomous Region in China.

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Oxyclozanide and triclabendazole effectively restored the health of infected buffaloes and reduced the EPG of F. hepatica.

Amphistomes

Amphistomes, commonly referred to as 'stomach' or 'rumen' flukes because of the localization of these flukes in the stomach of ruminants, are digenetic trematodes distinguished by the absence of an oral sucker and the position of the ventral sucker or acetabulum at the posterior end of the body. The body is characterized by leaf-like fleshy structure, pink or red in colour with a large posterior sucker. Amphistomes are an important group of parasites since they cause 'amphistomiasis' (variously known as paramphistomosis/amphistomosis), a serious disease of great economic importance in ruminants worldwide. These parasites have a broad spectrum of definitive hosts together with a wide geographical distribution. Though, they form a continuous evolutional lineage from fishes to mammals, amphistomes mainly inhabit the rumen and reticulum of ruminant mammals, while some species occur in the large intestine or parenteric sites of ruminants, pigs, equines and man.

Diagnostic potential of low molecular weight excretory secretory proteins of Paramphistomum epiclitum for caprine amphistomosis

In the present study, the 75% alcoholic fractionation of excretory-secretory (ES) antigen isolated from 200 to 300 live P. epiclitum was assessed for its diagnostic potential for the detection of caprine amphistomosis by using antibody detection enzyme immunoassay. Prior to enzyme immunoassay, 75% alcoholic fractionation of excretory-secretory (ES) antigen was subjected to SDS- PAGE and western blot analysis for the presence of immunoreactive polypeptides. SDS-PAGE analysis of ES antigen resolved a total 7 polypeptides bands of size 56, 27, 25, 22.5, 12, 11 and 10 kDa. Western blot analysis revealed only two immunoreactive polypeptides (11 kDa and 12 kDa) when polypeptides resolved in SDS-PAGE were probed with known positive pooled serum. None of the polypeptides showed reactions with pooled known negative serum. The working dilutions of antigen, sera and conjugates were determined by checkerboard titration for employing ELISA and cut-off O.D. was calculated 0.616 by using the mean absorbance value of 11 negative kid sera. The sensitivity and specificity of ELISA was found to be 100% and 86.76%, respectively. As per kappa value estimation, the strength of agreement was found to be good. Antibodies to 75% alcoholic fractionation of ES antigen was detected in 20% goats (n = 160) of either sex, although faecal examination detected 10.6% goats to be infected with amphistomosis. The study confirmed that 75% alcoholic fractionation of ES antigen of P. epiclitum based ELISA had good value for serodiagnosis of caprine amphistomosis.

Preparation and characterization of excretory and secretory antigen of Cotylophoron cotylophorum and Gastrothylax crumenifer

Excretory and secretory antigen of adult Cotylophoron cotylophorum and Gastrothylax crumenifer was prepared and characterized by SDS-PAGE. Adult paramphistomes were collected in PBS from rumen of sheep slaughtered at Perambur and Villivakkam slaughter houses, Chennai, Tamil Nadu. Excretory/Secretory (E/S) antigens of G. crumenifer and C. cotylophorum were prepared by incubating in PBS at 28.3 °C overnight in a shaking incubator and centrifuged. The culture supernatant was used as antigen. The protein concentration of E/S antigens of C. cotylophorum and G. crumenifer ranged from 0.4 to 7.1 mg/ml and 3.3 to 5.9 mg/ml, respectively. SDS-PAGE analysis of E/S antigen of C. cotylophorum revealed two polypeptide bands from the range of 32 and 40 kDa. Whereas, SDS-PAGE analysis of E/S antigen of G. crumenifer revealed only one polypeptide band of 35 kDa. Excretory/secretory antigen may be used for serodiagnosis of paramphistomosis infection in sheep.

Recent Research Progress in China on Haemonchus contortus

Haemonchus contortus is one of the most important parasites of ruminants with worldwide distribution that can bring huge economic losses to the breeding industry of cattle, sheep, and goats. In recent 20 years, studies on H. contortus in China mainly focused on the epidemiology, population genetics, anthelmintic resistance, structural and functional studies of important genes regulating the development of this parasite, interaction between parasite molecules and host cells and vaccine development against haemonchosis, and achieved good progress. However, there is no systematic review about the studies by Chinese researchers on H. contortus in China. The purpose of this review is to bring together the findings from the studies on H. contortus in China in order to obtain the knowledge gained from the recent studies in China and provide foundation for identifying future research directions to establish novel diagnostic methods, discover new drug targets and vaccine candidates for use in preventing and controlling H. contortus in China.

A review on epidemiology, global prevalence and economical losses of fasciolosis in ruminants

Fasciolosis is an important plant borne trematode zoonosis in ruminants caused by the Fasciola hepatica and Fasciola gigentica, It is classified as a neglected tropical disease and found in more than 50 countries especially where sheep and cattle are reared. Fasciolosis is a serious animal health problems in many rural and urban areas of world, causing significant financial losses due to decrease in production and viscera condemnation in animals. Accurate diagnosis of fasciolosis is always remained a challenging task for the field practitioners. There is no comprehensive summary on the occurrence and distribution of the infection at international level. Therefore, we intended to provide a complete overview on the prevalence and epidemiology of fasciolosis in farm animals from a global prospective. It includes to map the global distribution of fasciolosis in different areas of the world to identify the endemic regions which may be a source of potential disease outbreak. The financial liability related to fasciolosis on the livestock production has also been addressed. For this purpose, the published data during 2000-2015 (15 years) on fasciolosis was reviewed and collected by electronic literature search of four databases including Google, PubMed, Science Direct, and Web of Science. Data presented are contemplated to enhance our current understanding of the parasite's geographical distribution, host range, and economic losses. Information provided would be useful for the application of more effective control strategies against fasciolosis in different geo-economics regions of the world.

First survey of parasitic helminths of goats along the Han River in Hubei Province, China

Diseases caused by parasitic helminths cause considerable production and economic losses in livestock worldwide. Understanding the epidemiology of these parasites has important implications for controlling them. The main purpose of the present study was to estimate the prevalence of key parasitic helminths in goats along the Han River in Zhanggang, Hubei Province (from January to December 2014). We used faecal flotation and sedimentation techniques as well as PCR-based DNA sequencing to detect and identify helminths. Results showed that the prevalence of helminths was high throughout the year, particularly for gastrointestinal nematodes. These first findings provide useful baseline information for goat helminths in Zhanggang, and a starting point for the implementation of control programs. With an increased expansion of the goat industry in China, the findings also emphasise the need to undertake prevalence surveys in other regions of China where extensive farming practices are used.

First Record of Paramphistomes Fischoederius cobboldi and Paramphistomum epiclitum Detected in Bovine Rumen from a Local Market of Savannakhet Province, Lao PDR

In the present study, we report on the occurrence of paramphistomes, Fischoederius cobboldi and Paramphistomum epiclitum, in Lao PDR with the basis of molecular data. Parasite materials were collected from bovines bred in Ban Lahanam area, Savannakhet Province, Lao PDR at Lahanam public market. Morphological observations indicated 2 different species of paramphistomes. The mitochondrial gene cox1 of the specimens was successfully amplified by PCR and DNA sequencing was carried out for diagnosis of 11 specimens. Pairwise alignment of cox1 sequences were performed and confirmed F. cobboldi and P. epiclitum infecting bovines in Laos. Although there were many limiting points, as the small number of worm samples, and the restricted access of the animal host materials, we confirmed for the first time that 2 species of paramphistomes, F. cobboldi and P. epiclitum, are distributed in Lao PDR. More studies are needed to confirm the paramphistome species present in Savannakhet and its hosts to clear the natural history of these parasites of ruminants in the region and measure the impact of this parasite infection in the life and health of the local people.

The complete mitochondrial genome of Gastrothylax crumenifer (Gastrothylacidae, Trematoda) and comparative analyses with selected trematodes

In the present study, we sequenced and analyzed the mitochondrial (mt) genome of Gastrothylax crumenifer and compared it with other selected trematodes. The full mt genome of G. crumenifer was amplified, sequenced, assembled, analyzed and then subjected to phylogenetic analysis. The complete mt genome of G. crumenifer is 14,801 bp in length and contains two rRNA genes, two non-coding regions (LNR and SNR), 12 protein-coding genes, and 22 transfer RNA genes. The gene organization of the G. crumenifer mt genome is the same as that of other trematodes, except for Schistosoma haematobium and Schistosoma spindale. All the genes are transcribed in the same direction and rich in "A + T", which is in accordance with other trematodes, such as Fasciola hepatica, Paramphistomum cervi, and Fischoederius elongatus. Phylogenetic analysis using concatenated amino acid sequences of the 12 protein-coding genes showed that G. crumenifer is closely related to F. elongatus. The availability of mt genome sequence of G. crumenifer can provide useful DNA markers for studying the molecular epidemiology and population genetics of this parasite and other paramphistomes.

The anthelmintic effects of the ethanol extract ofTerminalia catappaL. leaves against the ruminant gut parasite,Fischoederius cobboldi

Presently, no effective anthelmintic drugs have been used to treat and control paramphistomosis, a severe disease of ruminants. In this study, we have investigated thein vitroanthelmintic effect of the leaves ofTerminalia catappaL. crude extract (TcCE) and albendazole (ABZ) on adultFischoederius cobboldiafter incubating the flukes in RPMI-1640 medium containing the TcCE at various doses and times. The TcCE-treated flukes at all dosages exhibited rapid decrease of motility, and the relative motility (RM) values were decreased sharply from start to 3 h. Worms were killed after 6 and 12 h of treatment with 1000, 1500 and 2000µg mL−1as well as 500µg mL−1of TcCE, respectively. By light microscopy examination, the flukes exhibited the earliest alteration in a limited area of the tegument. At scanning electron microscopy level, the flukes’ tegument showed similar sequence of morphological alterations after treatment with ABZ and TcCE that consisted of swelling of ridges and folds, followed by blebbing and rupturing of the blebs, leading to the erosion, lesion and disruption of the tegument. Hence,in vivostudies should be performed to examine whether the TcCE may serve as a powerful anthelmintic drug for treatment of paramphistomosis.

Current status of fasciolosis in Vietnam: an update and perspectives

Vietnam is recognized to be endemic for fasciolosis. However, most of the available publications have not been published in international journals. This review is based on national and international Vietnamese publications and highlights the current status of fasciolosis in Vietnam. It also provides some information available for neighbouring countries. Updated data on responsible species, distribution, transmission and control aspects are summarized. The central region of Vietnam is reported as being highly endemic for fasciolosis, with a high number of human patients (more than 20,000 in 2011). Fasciola gigantica is reported to be the main species in Vietnam. However, hybrids between F. gigantica and F. hepatica were identified. Both humans and animals are infected by the ingestion of raw vegetables and possibly contaminated drinking water. Three lymnaeid snail species (Austropeplea viridis, Radix auricularia and Radix rubiginosa) may act as intermediate hosts of Fasciola spp. However, due to the likely misidentification of snail species and cercariae during the past decade the critical analysis of published data is difficult. A better understanding of transmission aspects of fasciolosis would allow the implementation of preventive measures of this important neglected zoonotic disease.

De novo assembly and characterization of the transcriptome of the pancreatic fluke Eurytrema pancreaticum (trematoda: Dicrocoeliidae) using Illumina paired-end sequencing

Eurytrema pancreaticum is one of the most common trematodes living in the pancreatic and bile ducts of ruminants and also occasionally infects humans, causing eurytremiasis. In spite of its economic and medical importance, very little is known about the genomic resources of this parasite. Herein, we performed de novo sequencing, assembly and characterization of the transcriptome of adult E. pancreaticum. Approximately 36.4 million high-quality clean reads were obtained, and the length of the transcript contigs ranged from 66 to 19,968 nt with mean length of 479 nt and N50 length of 1094 nt, and then 23,573 unigenes were assembled. Of these unigenes, 15,353 (65.1%) were annotated by blast searches against the NCBI non-redundant protein database. Among these, 15,267 (64.8%), 2732 (11.6%) and 10,354 (43.9%) of the unigenes had significant similarity with proteins in the NR, NT and Swiss-Prot databases, respectively. 5510 (23.4%) and 4567 (19.4%) unigenes were assigned to GO and COG, respectively. 8886 (37.7%) unigenes were identified and mapped onto 254 pathways in the KEGG Pathway database. Furthermore, we found that 105 (1.18%) unigenes were related to pancreatic secretion and 61 (0.7%) to pancreatic cancer. The present study represents the first transcriptome of any members of the family Dicrocoeliidae, which has little genomic information available in the public databases. The novel transcriptome of E. pancreaticum should provide a useful resource for designing new strategies against pancreatic flukes and other trematodes of human and animal health significance.

Prevalence and pathological study of Paramphistomum infection in the small intestine of slaughtered ovine

Paramphistomiasis, a trematode infectious disease in ruminants, has been neglected but has recently emerged as an important cause of productivity loss. The small intestine of slaughtered sheep was collected weekly from abattoirs (Kermanshah, Sanandaj, Tabriz and Urmia Slaughterhouses) to monitoring the seasonal occurrence of Paramphistomosis, 2,421 sheep carcasses (743 male (30.69 %) and 1,678 female (69.31 %)) were examined, out of which 0.041 % were positive for Paramphistomum infestation. Furthermore, upon evaluation Paramphistomum termatodes, Gastrothylax crumenifer and Cotylophoron detected as well. Overall, the small intestinal infestation by such parasite was 0.041 % which contained hyperemia, severe congestion and haemorrhage. The highest infection in the sheep infected with Paramphistomum spp. was found during the summer (July to August) (6.7, 2 %) and followed by the autumn seasons (November to October) (3.8, 2.3 %). Microscopic study of the small intestine revealed dilatation of intestinal glands, destruction of superficial glands, replacement of fibrin, diffuse infiltration of inflammatory cells and fibrinonecrotic enteritis. Other changes as congestion hemorrhage and nodules of Ostertagia were observed in total examination of small intestines. According to statistical analysis by SPSS software and Chi square test revealed that there is significant difference between pathologic changes, seasons and ecological situations of the region (p < 0.05). There was no significant difference between age, gender and sample pH of examined sheep (p > 0.05).According to the results of pathologic changes of sheep small intestines, preventive measurements in the area should be taken to decrease the damages, so applying a parasitic control program is recommended.

Molecular characterization of Gastrothylax crumenifer (Platyhelminthes: Gastrothylacidae) from goats in the western part of India by LSU of nuclear ribosomal DNA

The rumen parasite, Gastrothylax crumenifer (Platyhelminthes: Gastrothylacidae), is a highly pathogenic trematode parasite of goat (Capra hircus). It sucks blood that causes acute disease like anemia, and severe economic losses occur due to morbidity and mortality of the ruminant infected by these worms. The study of these rumen paramphistomes, their infection, and public health importance remains unclear in India especially in the western part of state Uttar Pradesh (U.P.), Meerut, India, where the goat meat consumption is very high. This paper provides the molecular characterization of G. crumenifer recovered from the rumen of Capra hircus from Meerut, U.P., India by the partial sequence of 28S rDNA. Nucleotide sequence similarity searching on BLAST of 28S rDNA from parasites showed the highest identity with those of G. crumenifer from the same host Capra hircus. This is the first report of molecular identification of G. crumenifer from this part of India.

Epizootological study of small ruminant gastrointestinal strongyles in Gamo-Gofa Zone, Southern Ethiopia

The study was conducted with the objective to estimate the prevalence of gastrointestinal strongyles and identifying the prevailing strongyle species Gamo-Gofa Zone. A total of 598 animals (241 sheep and 357 goats) and 45 animals (20 sheep and 25 goats) were examined coproscopically and by post mortem, respectively. The overall coproscopic prevalence of strongylosis in the study area was 51.4 %. Strongyles were more prevalent in sheep than goats (95 % CI is 74.6-84.8 % and 58.6-68.6 % for sheep and goats, respectively; P < 0.05). A higher prevalence (P < 0.05) of strongyles infection was recorded in the midland and highland than the lowland, and in wet season than the dry season. The mean fecal egg count was found to be significantly higher (P < 0.05) in the midland area (908.7 ± 94.5) and in wet season (1,033.7 ± 84.2). The post mortem examination result indicated that the overall prevalence of gastrointestinal strongyles was 97.7 %; and a total of 11 strongyle species were identified of which Trichostrongylus axei, Teladorsagia species, Trichostrongylus colubriformis and Haemonchus contortus were the dominant and with higher load. During this study infection with multiple parasites, 3 and more 3, species were recorded in about 68 % goats and 85 % sheep. This study revealed the very high strongyle prevalence and higher proportion of multiple parasitism both in sheep and goats. Hence, it suggests the need to the institution of various control measures like strategic anthelmintic treatment for efficient utilization of the available small ruminant resources.

Expression of Caenorhabditis elegans-expressed Trans-HPS, partial aminopeptidase H11 from Haemonchus contortus

Aminopeptidase H11 present in the surface of intestine microvilli in Haemonchus contortus was identified as the most effective antigen candidate. However, its recombinant forms produced in Escherichiacoli, insect cells and yeast could not provide promising protection against H. contortus challenge, probably due to the inappropriate glycosylation and/or conformational folding. Herein, partial H11 containing the potential zinc-binding domain and two predicted glycosylation sites (nt 1 bp-1710 bp, Trans-HPS) was subcloned downstream of 5' flanking region of Caenorhabditis elegans cpr-1 gene in pPD95.77 vector, with the deletion of GFP gene. The recombinant was expressed in C. elegans and verified by blotting with anti-H11 and anti-Trans-HPS rabbit polyclonal antibodies and anti-His monoclonal antibody. Stably inherited Trans-HPS in worm descendants was achieved by integration using UV irradiation. Immunization with the crude Trans-HPS extracted from transgenic worms resulted in 37.71% reduction in faecal egg counts (FEC) (P<0.05) and 24.91% reduction in worm burden, but an upward curve with moderate rate of daily FEC in goats. These results suggested an apparent delay against H. contortus egg-laying in goats, which differed from that with bacteria-origin form of partial H11 (nt 670 bp-1710 bp, HPS) (26.04% reduction in FEC and 18.46% reduction in worm burden). These findings indicate the feasibility of sufficient C. elegans-expressed H11 for the immunological research and vaccine development.

Characterization of the complete nuclear ribosomal DNA sequences of Paramphistomum cervi

Sequences of the complete nuclear ribosomal DNA (rDNA) gene from five individual Paramphistomum cervi were determined for the first time. The five complete rDNA sequences, which included the 18S rDNA, the internal transcribed spacer 1 (ITS1), the 5.8S rDNA, the internal transcribed spacer 2 (ITS2), the 28S rDNA, and the intergenic spacer (IGS) regions, had a length range of 8,493–10,221 bp. The lengths of the investigated 18S, ITS1, 5.8S, ITS2, and 28S rDNA sequences, which were 1,994 bp, 1,293 bp, 157 bp, 286 bp, and 4,186 bp, respectively, did not vary. However, the IGS rDNA sequences had a length range of 577–2,305 bp. The 5.8S and ITS-2 rDNA sequences had 100% identity among the five investigated samples, while the identities among the IGS had a range of 53.7–99.8%. A comparative analysis revealed that different types and numbers of repeats were found within each ITS1 and IGS region, which may be related to the length polymorphism of IGS. The phylogenetic position of P. cervi in Paramphistomatidae was analyzed based on the 18S rDNA sequences. These results will aid in studying the intra- and interspecific variation of the Paramphistomatidae and the systematics and phylogenetics of Digenea.

Evaluation of antibody response to various developmental stage specific somatic antigens of Paramphistomum epiclitum in goats

Electrophoretic analysis of various developmental stage specific somatic antigens of Paramphistomum epiclitum (Digenea: Paramphistomidae), namely, metacercariae (McAg), immature intestinal flukes (ImIAg), immature ruminal flukes (ImRAg), and adult flukes (AAg), was done by native polyacrylamide gel electrophoresis. Result revealed presence of 3 (range 15.2-40.3 kDa), 13 (9.3-121.2 kDa), 14 (9.3-169.3 kDa), and 15 (8.0-169.3 kDa) polypeptides in McAg, ImIAg, ImRAg, and AAg, respectively. With an aim to identify a suitable immunodiagnostic antigen for early diagnosis of amphistomosis, the IgG antibody response to various developmental stage antigens in goats experimentally infected with metacercariae of P. epiclitum was evaluated by ELISA. The highest OD values were recorded with ImIAg which ranged between 0.23 and 0.55 with a significant increase from the 2nd week till 8th week of infection with a peak at 6th week. The analysis of statistical significance using a one-way analysis of variance with multiple pair wise comparisons revealed that IgG response was significantly higher with all antigens (P < 0.01) except McAg (P > 0.05) with a maximum mean difference of 0.1838 in comparison to control with ImIAg, thus, indicating that ImIAg which could be further exploited for its potential is a candidate for immunodiagnostic antigen for early diagnosis of amphistomosis.

Comparative analyses of the complete mitochondrial genomes of the two ruminant hookworms Bunostomum trigonocephalum and Bunostomum phlebotomum

Bunostomum trigonocephalum and Bunostomum phlebotomum are blood-feeding hookworms of sheep and cattle, causing considerable economic losses to the live stock industries. Studying genetic variability within and among hookworm populations is critical to addressing epidemiological and ecological questions. Mitochondrial (mt) DNA is known to provide useful markers for investigations of population genetics of hookworms, but mt genome sequence data are scant. In the present study, the complete mitochondrial DNA (mtDNA) sequences of the sheep and goat hookworm B. trigonocephalum were determined for the first time, and the mt genome of B. phlebotomum from yak in China was also sequenced for comparative analyses of their gene contents and genome organizations. The lengths of mt DNA sequences of B. trigonocephalum sheep isolate, B. trigonocephalum goat isolate and B. phlebotomum China yak isolate were 13,764bp, 13,771bp and 13,803bp in size, respectively. The identity of the mt genomes was 99.7% between B. trigonocephalum sheep isolate and B. trigonocephalum goat isolate. The identity of B. phlebotomum China yak isolate mt genomes was 85.3% with B. trigonocephalum sheep isolate, and 85.2% with B. trigonocephalum goat isolate. All the mt genes of the two hookworms were transcribed in the same direction and gene arrangements were consistent with those of the GA3 type, including 12 protein-coding genes, 2 rRNA genes and 22 tRNA genes, but lacking ATP synthetase subunit 8 gene. The mt genomes of B. trigonocephalum and B. phlebotomum were similar to prefer bases A and T, the contents of A+T are 76.5% (sheep isolate), 76.4% (goat isolate) and 76.9% (China yak isolate), respectively. Phylogenetic relationships reconstructed using concatenated amino acid sequences of 12 protein-coding genes with three methods (maximum likelihood, Bayesian inference and neighbor joining) revealed that the B. trigonocephalum and B. phlebotomum represent distinct but closely-related species. These data provide novel and useful genetic markers for studying the systematics, and population genetics of the two ruminant hookworms.

Differential diagnosis of Moniezia benedeni and M. expansa (Anoplocephalidae) by PCR using markers in small ribosomal DNA (18S rDNA)

Moniezia benedeni and M. expansa are common ruminant tapeworms of worldwide distribution, causing gastrointestinal disorders and even death in sheep and goats. In this study, a polymerase chain reaction- (PCR-) based approach for precise species identification was developed and also applied to faecal DNA diagnosis of the tapeworm infection. Since nuclear ribosomal DNA (rDNA) appears to be a useful target for species and/or strain markers, the 18S regions of the rDNA of M. benedeni and M. expansa were amplified and sequenced. The lengths and GC contents of the regions sequenced were 2476-2487 bp and 51.9-52.1% for M. benedeni and 2473 bp and 51.9-52.0% for M. expansa, respectively. Alignment and comparison of the 18S sequences of the two species showed 92.5-93.3% homology. No matches for the 18S regions of M. benedeni and M. expansa were found with other species by BLAST search, which made the 18S sequences appropriate markers for the design of distinctive primers for the two Moniezia species. Our 18S-based PCR could detect as low levels as 0.5 pg genomic DNA or the DNA extracted from 0.2 g faecal sample collected from the rectum of an M. expansa-infected goat. The results indicate that this PCR approach is a reliable alternative for the differential diagnosis of Moniezia species in faecal samples.

The mitochondrial genome of Paramphistomum cervi (Digenea), the first representative for the family Paramphistomidae

We determined the complete mitochondrial DNA (mtDNA) sequence of a fluke, Paramphistomum cervi (Digenea: Paramphistomidae). This genome (14,014 bp) is slightly larger than that of Clonorchis sinensis (13,875 bp), but smaller than those of other digenean species. The mt genome of P. cervi contains 12 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes and 2 non-coding regions (NCRs), a complement consistent with those of other digeneans. The arrangement of protein-coding and ribosomal RNA genes in the P. cervi mitochondrial genome is identical to that of other digeneans except for a group of Schistosoma species that exhibit a derived arrangement. The positions of some transfer RNA genes differ. Bayesian phylogenetic analyses, based on concatenated nucleotide sequences and amino-acid sequences of the 12 protein-coding genes, placed P. cervi within the Order Plagiorchiida, but relationships depicted within that order were not quite as expected from previous studies. The complete mtDNA sequence of P. cervi provides important genetic markers for diagnostics, ecological and evolutionary studies of digeneans.

Morphology and histology of the adult Paramphistomum gracile Fischoeder, 1901

In the present study, we evaluated the histological morphology of the adult Paramphistomum (P.) gracile. Adult flukes with bodies 5~15 mm in length and 2~7 mm in width were subjected to histological analysis. Longitudinal and transversal serial-sections were stained with hematoxylin and eosin, and examined. The body surface and longitudinal section of P. gracile were also assessed using scanning electron microscopy. In this species, the anterior sucker and posterior sucker (acetabulum) were present on an anterior and posterior part of the body, respectively. The major folds were located in the areas of the anterior sucker, genital canal, and posterior sucker. The fluke membrane was spineless at the tegument surface and in the tegument tissue. Histological data showed structural-systematic characteristics of the digestive tract, reproductive tract, excretory tract, copulatory organs, connective tissues, and muscle tissues. We attempted to elucidate the histological characteristics of P. gracile that might increase the knowledge and understanding of rumen fluke morphology.

Genetic variability in the three mitochondrial genes among Oesophagostomum asperum isolates from different regions in Shaanxi and Hunan Provinces, China

The present study examined sequence variations in three mitochondrial DNA (mtDNA) regions, namely, NADH dehydrogenase subunit 5 (nad5), adenosine triphosphate subunit 6 (atp6) and cytochrome c oxidase subunit 3 (cox3), among Oesophagostomum asperum isolates from different regions in Shaanxi and Hunan provinces, China. The lengths for partial sequences of nad5 (pnad5), atp6 (patp6) and cox3 (pcox3) were 427 bp, 381 bp and 337 bp, respectively. The intra-specific sequence variations among all O. asperum samples were 0-2.11%, 0-1.84% and 0-1.48% for pnad5, patp6 and pcox3, respectively, while the inter-specific sequence differences among Oesophagostomum species in pig and small ruminants were 18-21.3% for pnad5, 18.3-24.5% for patp6 and 10.6-13.7% for pcox3. A phylogenetic analysis based on combined sequences of three mtDNA fragments indicated that all O. asperum isolates were grouped in one solid clade, and the Oesophagostomum spp. from pig were located in another clade. However, these mtDNA fragments could not reveal genetic relationships of geographical isolates of O. asperum in China. These results provided valuable information for studying population genetics of Oesophagostomum spp., and for controlling Oesophagostomum infection in animals as well as humans.

Identification and characterization of microRNAs in the pancreatic fluke Eurytrema pancreaticum

Background

Eurytrema pancreaticum is one of the most common flukes, which mainly infects ruminants globally and infects human beings accidentally; causing eurytremiasis that has high veterinary and economic importance. MicroRNAs (miRNAs) are small non-coding RNAs and are now considered as a key mechanism of gene regulation at the post-transcription level.

Methods

We investigated the global miRNA expression profile of E. pancreaticum adults using next-generation sequencing technology combined with real-time quantitative PCR.

Results

By using the genome of the closely-related species Schistosoma japonicum as reference, we obtained 27 miRNA candidates out of 16.45 million raw sequencing reads, with 13 of them found as known miRNAs in S. japonicum and/or S. mansoni, and the remaining 14 miRNAs were considered as novel. Five out of the 13 known miRNAs coming from one family named as sja-miR-2, including family members from miR-2a to miR-2e. Targets of 19 miRNAs were successfully predicated out of the 17401 mRNA and EST non-redundant sequences of S. japonicum. It was found that a significant high number of targets were related to “chch domain-containing protein mitochondrial precursor” (n = 29), “small subunit ribosomal protein s30e” (n = 21), and “insulin-induced gene 1 protein” (n = 9). Besides, “egg protein cp3842” (n = 2), “fumarate hydratase” (n = 2), “ubiquitin-conjugating enzyme” (n = 2), and “sperm-associated antigen 6” (n = 1) were also found as targets of the miRNAs of E. pancreaticum.

Conclusions

The present study represents the first global characterization of E. pancreaticum miRNAs, which provides novel resources for a better understanding of the parasite, which, in turn, has implications for the effective control of the disease it causes.

Antigenic components, isolation and partial characterization of excretion-secretion fraction of Paramphistomum cervi

The immunogenic components of adult Paramphistomum cervi excretion-secretion (ES) fraction were revealed by SDS-PAGE and immunoblotting technique using sera from cattle naturally infected with P. cervi, Fasciola gigantica, strongylids, Trichuris sp., and Strongyloides sp. By SDS-PAGE, it was found that the ES fraction comprised 13 distinct protein bands. Immunoblotting analysis of these proteins exhibited nine prominent antigenic bands which were recognized by paramphistomosis antisera. These antigenic proteins had molecular weights ranging from 10-170 kDa. One antigenic protein band of 40 kDa was found to give a consistent reaction with sera from all infected cattle. Its diagnostic sensitivity, specificity and accuracy using this test were 100%, 98.9% and 99.3%, respectively. The positive and negative predictive values were 98% and 100%, respectively. The 40 kDa antigen was partially purified by gel filtration and ion-exchange chromatography. The antigenicity of 40 kDa protein for diagnosis of P. cervi infection was confirmed by immunoblotting and indirect ELISA (at 1:78,125 dilution) using a pool of sera and individual serum samples from infected cattle. The present findings suggest that the 40 kDa protein may be used as a diagnostic antigen for paramphistomosis.

Characterization of Oesophagostomum asperum and O. columbianum by internal transcribed spacers of nuclear ribosomal DNA

In the present study, the internal transcribed spacers (ITS) of ribosomal DNA (rDNA) of Oesophagostomum asperum and O. columbianum were amplified and sequenced. The ITS-1, 5.8S and ITS-2 rDNA sequences of O. asperum were 374 bp, 153 bp and 259 bp in length, respectively, and the corresponding sequences of O. columbianum were 259, 153 and 218 bp in length, respectively. Sequence differences in the ITS-1 and ITS-2 rDNA between the two Oesophagostomum species were 9.5–10.2% and 12.7–13.9%, respectively. Sequence differences in the ITS-1 and ITS-2 rDNA among members of the genus Oesophagostomum were 2.5–11.6% and 6.8–22.3%, respectively. Based on genetic markers in the ITS rDNA, an effective polymerase chain reaction (PCR) approach was developed to differentiate O. columbianum from O. asperum with a sensitivity of 0.2 ng/μl DNA. Since accurate characterization of parasites at different taxonomic levels is essential for population genetic studies and control of parasitosis, the present findings have important implications for studying epidemiology, taxonomy and population biology, as well as for the control of oesophagostomiasis.

Sequence variability in four mitochondrial genes among Bunostomum trigonocephalum isolates from four provinces in China

The present study examined sequence variability in four mitochondrial genes, namely cytochrome c oxidase subunit (cox1), cytochrome b (cytb) and NADH dehydrogenase subunits 1 and 5 (nad1 and nad5), among Bunostomum trigonocephalum isolates from four different geographic regions in China. Ten B. trigonocephalum samples were collected from each of the four provinces (Heilongjiang, Jilin, Shaanxi and Yunnan), China. A part of the cox1 (pcox1), cytb (pcytb), nad1 and nad5 genes (pnad1 and pnad5) were amplified separately from individual hookworms by polymerase chain reaction (PCR) and were subjected to direct sequencing in order to define sequence variations and their phylogenetic relationships. The intra-specific sequence variations within B. trigonocephalum were 0–1.9% for pcox1, 0–2.0% for pcytb, 0–1.6% for pnad1 and 0–1.7% for pnad5. The A+T contents of the sequences were 69.6–70.4% (pcox1), 71.9–72.7 (pcytb), 70.4–71.1% (pnad1) and 72.0–72.6% (pnad5). However, the inter-specific sequence differences among members of the family Ancylostomatidae were significantly higher, being 12.1–14.2% for pcox1, 13.7–16.0 for cytb, 17.6–19.4 for nad1 and 16.0–21.6 for nad5. Phylogenetic analyses based on the combined partial sequences of cox1, cytb, nad1 and nad5 using three inference methods, namely Bayesian inference (Bayes), maximum likelihood (ML) and maximum parsimony (MP), revealed that all the B. trigonocephalum samples form monophyletic groups, but samples from the same geographical origin did not always cluster together, suggesting that there was no obvious geographical distinction within B. trigonocephalum based on sequences of the four mtDNA genes. These results demonstrated the existence of low-level intra-specific variation in mitochondrial DNA (mtDNA) sequences among B. trigonocephalum isolates from different geographic regions.

Fischoederius cobboldi: A scanning electron microscopy investigation of surface morphology of adult rumen fluke

Adults Fischoederius cobboldi are conical-shaped, concave ventrally and convex dorsally, measures about 8-10mm in length and 4-6mm in width across the mid section. Scanning electron microscopy (SEM) of entire body showed that the tegumental surface exhibits highly corrugation and transverse folds alternating with grooves and without spines. At higher magnification, the surface of each fold is further increased with a meshwork of ridges separated by irregular-sized pits. The ventral surface has more complex corrugations and invaginations than those of the dorsal surface of the body. Both anterior and posterior suckers have thick edges covered with transverse folds and appear spineless. The genital pore is located at the anterior one-third of the body. There are two types of sensory papillae on the surface: type 1 is bulbous in shape and nipple-like tips, measuring 10-15 μm in diameter at the base, and also type 2 is a similar shape and has short cilia on tips. These sensory papillae occur in large clusters, each having between 7 and 25 units depending on the region of the body. Clusters of papillae on the ventral surface and around the anterior suckers tend to be more abundant and larger in size. The dorsal side of the body exhibit similar surface features, but papillae appear less numerous and are smaller. Corrugations and invaginations of the dorsal aspect are also less extensive than those on the ventral surface of the body.