Amphistomes

Rumen Fluke in Cattle and Buffaloes in Asia: A Review

Rumen fluke is a parasitosis that infects ruminant animals across a wide geographical range of countries. It is a severe infection in temperate and tropical climate regions of Asia, Australia, Africa, and Europe, which cause significant economic losses. In this review, the available information to date on rumen fluke species infecting cattle and buffaloes in Asian countries is evaluated. The citation search was performed through specific keywords, literature published from 1964 to 2021, retrieved from electronic databases: Scopus, Web of Science, Pub Med, Education Resources Information Center (ERIC), Science Direct, Elsevier, and Google Scholar. Twenty-six (26) rumen fluke species belonging to two families: Paramphistomidae 61.5% (16/26) and Gastrothylacidae 38.4% (10/26), were reported in cattle and buffaloes in fourteen Asian countries. Paramphistomum cervi and Cotylophoron cotylophorum are the most prevalent species with broader distribution in countries than the other genera. The coprological prevalence varies from 0.8% to 98.17% and 0.86% to 78.4% in cattle and buffaloes, respectively. The prevalence of rumen fluke by fluke counts method range between 6.45% to 90.6% and 4.29% to 75.07% in cattle and buffaloes, respectively. The sedimentation method and fluke count are reliable tests for detecting rumen fluke in live and slaughtered animals. In conclusion, the rumen fluke should be considered a critical production disease that affects cattle and buffaloes in Asia. Further studies are necessary to determine the rumen fluke-snail associations, develop diagnostic tests to detect prepatent infections in the definitive host, determine the economic importance of rumen fluke, and determine the efficacy of different anthelmintic in the treatment of patent infections in the definitive host.

Invasive snails, parasite spillback, and potential parasite spillover drive parasitic diseases of Hippopotamus amphibius in artificial lakes of Zimbabwe

Background

Humans impose a significant pressure on large herbivore populations, such as hippopotami, through hunting, poaching, and habitat destruction. Anthropogenic pressures can also occur indirectly, such as artificial lake creation and the subsequent introduction of invasive species that alter the ecosystem. These events can lead to drastic changes in parasite diversity and transmission, but generally receive little scientific attention.

Results

In order to document and identify trematode parasites of the common hippopotamus (Hippopotamus amphibius) in artificial water systems of Zimbabwe, we applied an integrative taxonomic approach, combining molecular diagnostics and morphometrics on archived and new samples. In doing so, we provide DNA reference sequences of the hippopotamus liver fluke Fasciola nyanzae, enabling us to construct the first complete Fasciola phylogeny. We describe parasite spillback of F. nyanzae by the invasive freshwater snail Pseudosuccinea columella, as a consequence of a cascade of biological invasions in Lake Kariba, one of the biggest artificial lakes in the world. Additionally, we report an unknown stomach fluke of the hippopotamus transmitted by the non-endemic snail Radix aff. plicatula, an Asian snail species that has not been found in Africa before, and the stomach fluke Carmyerius cruciformis transmitted by the native snail Bulinus truncatus. Finally, Biomphalaria pfeifferi and two Bulinus species were found as new snail hosts for the poorly documented hippopotamus blood fluke Schistosoma edwardiense.

Conclusions

Our findings indicate that artificial lakes are breeding grounds for endemic and non-endemic snails that transmit trematode parasites of the common hippopotamus. This has important implications, as existing research links trematode parasite infections combined with other stressors to declining wild herbivore populations. Therefore, we argue that monitoring the anthropogenic impact on parasite transmission should become an integral part of wildlife conservation efforts.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12915-021-01093-2.

Paramphistome Species in Water Buffaloes and Intermediate Hosts in the Kızılırmak Delta in Samsun Province, Turkey

PURPOSE

This study was carried out to determine the paramphistome species parasitizing water buffaloes (WBs) grazing in the Kızılırmak Delta in Samsun Province, Turkey, and the intermediate hosts of the parasites.

METHODS

Between August 2016 and July 2018, abattoirs in Samsun Province were visited weekly and 139 slaughtered WBs were examined for paramphistome species. In the same period, 550 snails (300 Galba truncatula, 200 Physella (Physa) acuta and 50 Planorbis planorbis) were collected from pastures grazed by WBs during monthly sampling in the spring and autumn. Adult parasites were identified through the use of histological and molecular methods and larval stages were identified with a molecular method.

RESULTS

Forty-five of the 139 WBs (32.4%) were infected with species of the family Paramphistomidae and a total of 4761 (mean 105.8) parasites were collected from them. The genera Paramphistomum and Calicophoron were distinguished from each other by examining the development status of the pars musculosa and the degree of lobulation of the testes in histological sections. Calicophoron daubneyi was present in all the infected animals and Paramphistomum cervi in only 3 of the same animals. There were larval forms in only 19 of the specimens identified as G. truncatula. Calicophoron daubneyi was molecularly diagnosed in 12 of the 19 infected G. truncatula and this result was confirmed by PCR and PCR-RFLP. Calicophoron daubneyi was also identified molecularly as being present in all 45 infected adult WBs and as developmental stages in 12 of 300 (4%) intermediate hosts, G. truncatula. The DNA sequences from the adult parasites in the definitive hosts and larval forms in intermediate hosts were allocated the codes MH939278 and MH939279, respectively, in GenBank.

CONCLUSION

For the first time in Turkey, C. daubneyi was identified molecularly and its intermediate host was identified as G. truncatula. Calicophoron daubneyi was identified as the overwhelmingly dominant paramphistome species in WBs in the Kızılırmak Delta, with P. cervi found in mixed infections in only three animals.

Morphological and molecular identification of Pfenderius heterocaeca (Trematode: Paramphistomoidea) from Sumatran elephant (Elephas maximus sumatranus)

Background and Aim:

Paramphistomiasis is common in tropical countries such as Indonesia and affects livestock and various endemic wild animals such as Sumatran elephants. However, the specific species of paramphistomoid worm that causes paramphistomiasis are rarely reported. The study aims at identifying paramphistomoid worm that infects Sumatran elephants.

Materials and Methods:

Flukes were collected from the feces of five semi-captive Sumatran elephants that lived at Tegal Yoso Elephant Response Unit in Way Kambas National Park, in 2018, after treatment of oxyclozanide 1 g at the dose of approximately 5-8 mg/kg of body weight. Eight paramphistomoid worms were flattened and stained in Semichon’s carmine for morphological identification, and five other worms were used for molecular identification at second internal transcribed spacer (ITS-2) of ribosomal deoxyribonucleic acid sequence.

Results:

Forty-five flukes were collected from five Sumatran elephants in Lampung, Indonesia. Eight paramphistomoid worms were morphologically identified as Pfenderius heterocaeca and five isolates did not show any variation in ITS-2. Phylogenetic analysis showed that there was a close genetic relationship between our sample and Chiorchis fabaceus that had a family similar to the samples.

Conclusion:

Based on the morphological and molecular characteristics, the paramphistomoids found in Sumatran elephant on Way Kambas National Park are P. heterocaeca.

Zygocotyle lunata as a model for in vivo screening of anthelmintic activity against paramphistomes: Evaluation of efficacy of praziquantel, albendazole and closantel in experimentally infected mice

Paramphistomes are important parasites in veterinary medicine. There are few anthelmintic drugs available against them. The development of new drugs is urgently needed and this process can be accelerated through the development of rodent models for in vivo testing. Among the few paramphistomes that develop in rodents is the caecal fluke Zygocotyle lunata, a species with which several biological studies have been performed over several decades. Nevertheless, its use as a model for evaluation of anthelmintic drugs had not yet been evaluated. In the present study, we evaluated the efficacy of praziquantel (PZQ 300 mg/kg 5x), albendazole (ABZ 200 mg/kg 5x) and closantel (CLO 50 mg/kg single dose, 50 mg/kg 3x and 25 mg/kg 3x) for treatment of mice experimentally infected with Z. lunata. The animals were infected with 20 metacercariae of the parasite and were treated 30 days post-infection. Untreated groups were maintained as controls. Seven days after the treatments, the animals were euthanized for recovery and counting of parasites. We found that PZQ and ABZ, at the dosages and therapeutic schedule employed here, did not cause significant alterations in worm burden [worm counts 16.0 ± 2.8 (13-19), 17.6 ± 2.1 (14-19) and 16.2 ± 1.9 (13-18) (p = 0.51) in PZQ, ALB and control, respectively]. CLO 50 mg/kg in a single dose caused significant reduction in the number of parasites [treated: 1.8 ± 0.9 (1-3); control: 15.6 ± 2.5 (12-19)], although it did not result in complete elimination of the parasites in any animal. Despite the fact that three doses of CLO 50 mg/kg or CLO 25 mg/kg caused complete elimination of the parasites in most surviving animals, there was significant host mortality. In general, results here obtained are concordant with those of studies performed on ruminant paramphistomes. Given that Z. lunata can be maintained in laboratory rodents, it is a suitable model for screening anthelmintic drugs against paramphistomes.

Occurrence of endoparasites in wild Antillean manatees (Trichechus manatus manatus) in Colombia

The recognized impact of parasites in wildlife populations demands surveillance of endangered species like the Antillean manatees (Trichechus manatus manatus) in Colombia. We conducted a parasitological survey in four rescued sea cows in order to document the parasite diversity of this sirenian in the Caribbean wetland of Colombia and contribute to the molecular characterization of its trematodes. The flukes Chiorchis fabaceus, Nudacotyle undicola and the protozoans Eimeria manatus and E. nodulosa were identified in analysed faecal samples. For C. fabaceus and N. undicola, partial regions of ribosomal RNA genes were amplified and sequenced in order to infer their phylogenetic relations. The current study constitutes a new sirenian host (T. manatus manatus) record for the genus Eimeria and the trematode N. undicola.

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Gastrointestinal parasites of the Antillean manatee of Caribbean wetland in Colombia.

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First report of Eimeria species and N. undicola in the Antillean manatee (T. manatus manatus).

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First contribution to the phylogenetic knowledge of trematode parasites of manatees.

New approach to molecular characterization of Paramphistomum cervi and Carmyerius gregarius and comparative analyses with selected trematodes

The two ruminant parasites, Paramphistomum cervi and Carmyerius gregarius, were collected from fresh-slaughtered native cattle at local abattoirs in Sadat district, Menoufia province and identified morphologically, then molecularly by sequencing the nucleotides of 18S ribosomal RNA gene (18S rRNA). The nucleotide sequences of the two isolates were 456 (P. cervi) and 401 bases for (C. gregarius). The data were used along with those of several other helminth species from the GenBank to identify these two species genetically. The nucleotide sequences were aligned using multiple sequence alignments of nucleotides by Clustal W 12.1 V and construct their relationship. Neighbor-joining analytical method was used showing sister relationship between C. gregarius from Sadat district and Gastrodiscoides hominis (EF027096) with relative identity of (98%) due to the presence of single nucleotides polymorphisms (SNPs) in the form of indels as nine nucleotides positions. But when clustering of P. cervi Sadat isolate with Paramphistomoidea sp. S4 isolate P5 (GU735643), this relationship shows complete identity (99%) between them. The homology and diversity was done using Bayesian analyses in MrBayes v3.1. This work will give a useful guide for other researchers for the molecular taxonomic position of Paramphistomatidae spp. in Sadat district among the different species around the world.

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.