• Asian-Australasian Journal of Animal Sciences
• /
• v.28 no.6
• /
• pp.876-887
• /
• 2015

Dicer, an ribonuclease type III type endonuclease, is the key enzyme involved in biogenesis of microRNAs (miRNAs) and small interfering RNAs (siRNAs), and thus plays a critical role in RNA interference through post transcriptional regulation of gene expression. This enzyme has not been well studied in the Indian water buffalo, an important species known for disease resistance and high milk production. In this study, the primary coding sequence (5,778 bp) of bubaline dicer (GenBank: AB969677.1) was determined and the bubaline Dicer1 biocomputationally characterized to determine the phylogenetic signature among higher eukaryotes. The evolutionary tree revealed that all the transcript variants of Dicer1 belonging to a specific species were within the same node and the sequences belonging to primates, rodents and lagomorphs, avians and reptiles formed independent clusters. The bubaline dicer1 is closely related to that of cattle and other ruminants and significantly divergent from dicer of lower species such as tapeworm, sea urchin and fruit fly. Evolutionary divergence analysis conducted using MEGA6 software indicated that dicer has undergone purifying selection over the time. Seventeen divergent sequences, representing each of the families/taxa were selected to study the specific regions of positive vis-$\grave{a}$-vis negative selection using different models like single likelihood ancestor counting, fixed effects likelihood, and random effects likelihood of Datamonkey server. Comparative analysis of the domain structure revealed that Dicer1 is conserved across mammalian species while variation both in terms of length of Dicer enzyme and presence or absence of domain is evident in the lower organisms.

• Parasites, Hosts and Diseases
• /
• v.31 no.1
• /
• pp.1-6
• /
• 1993

Among taenited tapeworms inferting humans though pork or beef, Taenia solium Linnaeus 1758 and Taenia sagina Goeze 1782 have already been. Based on the morphologic characteristics of adult and metacestodes of Asian Taenia saginata, the third kind of human taeniid tapeworm konwn to disdute in Asian counteries, a new spscies name of Taenia asiatica is proposed. In addition to the known biology in their intermediate hosts, T.asiatica was diffierent morphologically from Taenia saginata Goeze 1782 in having the unarmed rostellum on the scolex of adlut, the large number of 'unterinetwigs' and the existence of 'posterior protuberance'. These structures in the gravid proglottids were used as taxonmic keys in taeniid tapeworms for the first time. T. asiatica metacestode (Cysticercus viscerotropica)was different morphologically from T. saginata metacestode (Cysticercus bovis) in having wartlike formations on external surface of the bladder wall.

• Pediatric Infection and Vaccine
• /
• v.8 no.1
• /
• pp.129-133
• /
• 2001

We experienced one rare case of Diphyllobothrium latum infection in childhood. It was proved by collection of worm after praziquantel treatment. Human diphyllobothriasis is chiefly caused through eating raw or unproperly cooked fish such as trout or salmon. This case was a 5-year old girl residing in Seoul, from whom a kind of pseudophyllidean tapeworm was detected in the feces. She would often eat sushi(raw fish) and had abdominal pain, but not revealed any sign of anemia. Obtained chain of worm segments that sized $0.25{\times}1.25cm$ was compatible with D. latum. Including the present 31 cases, total number of human D. latum infections proven by worms in Korea becomes 32 cases, and total number of child D. latum infections proven by worms in Korea becomes 4 cases.

• CELLMED
• /
• v.9 no.4
• /
• pp.9.1-9.4
• /
• 2019

Ayurveda is one of the ancient systems of traditional medicine in India, however, there is a lack of proper scientific research and controlled studies on efficacy and toxicity of several Ayurvedic formulations using the methods of modern science, which hinders the proper development of Ayurveda, both in India and abroad. The present study was undertaken to further corroborate the efficacy of some popular anthelmintic Ayurvedic medicines, as evident by the pharmacological effects of Ayurvedic formulations on body surface of a cestode parasite. This study employed a common intestinal cestode of domestic fowl, Raillietina sp., as a model parasite, that was exposed in vitro to different concentrations of three common Indian Ayurvedic anthelmintic drugs, namely Krimimudgar Ras, Kriminol and Vidangasava, and also to a modern anthelmintic drug, praziquantel (PZQ). After the paralysis of parasites, the specimens from the highest drug-treated concentration (50 mg/ml), praziquantel (1 mg/ml), and control groups, were collected and processed for scanning electron microscopic studies to document the effects of drugs on the body surface of parasite. In this study, maximum degree of alterations on parasite body surface was observed in the worms exposed to Krimimudgar Ras, indicating this drug to be highly efficacious against intestinal worms and brings out a transtegumental mode of action on parasite. In conclusion, the findings of present study suggest that of the three Ayurvedic formulations tested, Krimimudgar Ras possesses significant anthelmintic effects, which are mediated through parasite's body surface. Therefore, Krimimudgar Ras may be considered as a reliable anthelmintic Ayurvedic formulation, as validated through this study.

• Parasites, Hosts and Diseases
• /
• v.57 no.4
• /
• pp.417-422
• /
• 2019

From October 2015 to August 2018, tapeworm proglottids were obtained from 10 patients who were residents of Daegu and Gyeongbuk provinces and had a history of raw beef consumption. Most of them had no overseas travel experience. The gravid proglottids obtained from the 10 cases had 15-20 lateral uterine branches. A part of internal transcribed spacer 1 (ITS1) DNA of the 10 cases, amplified by polymerase chain reaction (PCR) and digested with AleI restriction enzyme, produced the same band pattern of Taenia saginata, which differentiated from T. asiatica and T. solium. Sequences of ITS1 and cytochrome c oxidase subunit 1 (cox1) showed higher homology to T. saginata than to T. asiatica and T. solium. Collectively, these 10 cases were identified as T. saginata human infections. As taeniasis is one of the important parasitic diseases in humans, it is necessary to maintain hygienic conditions during livestock farming to avoid public health concerns.

• Parasites, Hosts and Diseases
• /
• v.57 no.4
• /
• pp.423-427
• /
• 2019

Coenurosis is an important zoonotic helminthic disease caused by the larval stage of the tapeworm Taenia multiceps. This parasite typically infects the brain of the intermediate hosts, including sheep, goat, cattle and even humans. We report a case of T. multiceps infection in a yak confirmed by clinical symptoms, morphological characteristics, and molecular and phylogenetic analyses. The coenurus was thin-walled, whitish, and spherical in shape with a diameter of 10 cm. The parasite species was identified as T. multiceps by PCR amplification and sequencing of the 18S rRNA, cox1 and nad1 genes. Three gene sequences all showed high homology (all above 97%) with the reference sequences from different hosts. Moreover, phylogenetic reconstructions with the 3 published Taenia gene sequences confirmed that the Qinghai yak isolate was closely related to T. multiceps. Although there are advanced diagnosis and treatment methods for coenurosis, early infection is difficult to diagnose. Importantly, the findings of yak infection case should not be ignored due to its zoonotic potential.

• Parasites, Hosts and Diseases
• /
• v.59 no.3
• /
• pp.189-225
• /
• 2021

The use of albendazole and mebendazole, i.e., benzimidazole broad-spectrum anthelmintics, in treatment of parasitic infections, as well as cancers, is briefly reviewed. These drugs are known to block the microtubule systems of parasites and mammalian cells leading to inhibition of glucose uptake and transport and finally cell death. Eventually they exhibit ovicidal, larvicidal, and vermicidal effects on parasites, and tumoricidal effects on hosts. Albendazole and mebendazole are most frequently prescribed for treatment of intestinal nematode infections (ascariasis, hookworm infections, trichuriasis, strongyloidiasis, and enterobiasis) and can also be used for intestinal tapeworm infections (taeniases and hymenolepiasis). However, these drugs also exhibit considerable therapeutic effects against tissue nematode/cestode infections (visceral, ocular, neural, and cutaneous larva migrans, anisakiasis, trichinosis, hepatic and intestinal capillariasis, angiostrongyliasis, gnathostomiasis, gongylonemiasis, thelaziasis, dracunculiasis, cerebral and subcutaneous cysticercosis, and echinococcosis). Albendazole is also used for treatment of filarial infections (lymphatic filariasis, onchocerciasis, loiasis, mansonellosis, and dirofilariasis) alone or in combination with other drugs, such as ivermectin or diethylcarbamazine. Albendazole was tried even for treatment of trematode (fascioliasis, clonorchiasis, opisthorchiasis, and intestinal fluke infections) and protozoan infections (giardiasis, vaginal trichomoniasis, cryptosporidiosis, and microsporidiosis). These drugs are generally safe with few side effects; however, when they are used for prolonged time (>14-28 days) or even only 1 time, liver toxicity and other side reactions may occur. In hookworms, Trichuris trichiura, possibly Ascaris lumbricoides, Wuchereria bancrofti, and Giardia sp., there are emerging issues of drug resistance. It is of particular note that albendazole and mebendazole have been repositioned as promising anti-cancer drugs. These drugs have been shown to be active in vitro and in vivo (animals) against liver, lung, ovary, prostate, colorectal, breast, head and neck cancers, and melanoma. Two clinical reports for albendazole and 2 case reports for mebendazole have revealed promising effects of these drugs in human patients having variable types of cancers. However, because of the toxicity of albendazole, for example, neutropenia due to myelosuppression, if high doses are used for a prolonged time, mebendazole is currently more popularly used than albendazole in anti-cancer clinical trials.

• Parasites, Hosts and Diseases
• /
• v.22 no.1
• /
• pp.51-60
• /
• 1984

Two cases of natural human infection by Heterophyopsis continua (Heterophyidae) were identified by collection of adult worms in 1983 in Korea. And in order to know the source of infection a study on fish intermediate hosts was performed along the southwestern coastal areas. The cases were 21 and 50 year old males residing in southern coastal areas. They had the clinical complaints of non-specific gastrointestinal symptoms such as epigastric pain and one of them also complained the discharge of tapeworm segments. Praziquantel in single dose of 10~15mg/kg was given followed by purgation with magnesium salt and 2 and 46 specimens of H. continua were collected from the diarrheal stools. They said to have eaten raw ilesh of several kinds of brackish water fishes. The results of fish examination for metacercarial infection were as follows: I. Seventeen (663.0%) out of 27 perches (Lateolabrax japonicus) and 10 (29.4%) out of 34 gobies (Acantkogobius flavimanus) harboured the metacercariae but none of 42 mullets (Mugil cepkalus) were found to harbour them. 2. The average metacercarial density in perches was 55.1 and 18.7 per fish respectively. And the majority of the metacercariae were collected from the muscle of body portions in these fishes. 3. After the metaeercariae were experimentally fed to two rats and one young dog. two adult worms were recovered from the dog while none from the rats. These worms were also identified as H. continua. From the results it was concluded that the brackish water flshes which the human cases said to have eaten were the source of infection.

• Parasites, Hosts and Diseases
• /
• v.55 no.3
• /
• pp.319-325
• /
• 2017

We described 4 human infection cases of zoonotic fish-tapeworm, Diphyllobothrium nihonkaiense, identified with morphological and molecular characters and briefly reviewed Chinese cases in consideration of it as an emerging parasitic disease in China. The scolex and mature and gravid proglottids of some cases were seen, a rosette-shaped uterus was observed in the middle of the mature and gravid proglottids, and the diphyllobothriid eggs were yellowish-brown in color and displayed a small knob or abopercular protuberance on the opposite end of a lid-like opening. The average size of the eggs was recorded as $62-67{\times}42-45{\mu}m$. The parasitic materials gathered from 4 human cases were morphologically identified as belonging to the genera Diphyllobothrium and Adenocephalus. The phylogenetic analysis based on the nucleotide sequences of cytochrome c oxidase subunit 1 gene of the etiologic agents confirmed that the 4 cases were D. nihonkaiense infection. The finding of 4 additional D. nihonkaiense cases suggests that D. nihonkaiense might be a major causative species of human diphyllobothriasis in China. A combined morphological and molecular analysis is the main method to confirm D. nihonkaiense infection.

• Parasites, Hosts and Diseases
• /
• v.55 no.5
• /
• pp.523-532
• /
• 2017

A field survey studying intestinal parasites in humans and microbial pathogen contamination at environment was performed in a Laotian rural village to identify potential risks for disease outbreaks. A parasitological investigation was conducted in Ban Lak Sip village, Luang Prabang, Lao PDR involving fecal samples from 305 inhabitants as well as water samples taken from 3 sites of the local stream. Water analysis indicated the presence of several enteric pathogens, i.e., Aeromonas spp., Vibrio spp., E. coli H7, E. coli O157: H7, verocytotoxin-producing E. coli (VTEC), Shigella spp., and enteric adenovirus. The level of microbial pathogens contamination was associated with human activity, with greater levels of contamination found at the downstream site compared to the site at the village and upstream, respectively. Regarding intestinal parasites, the prevalence of helminth and protozoan infections were 68.9% and 27.2%, respectively. Eight helminth taxa were identified in fecal samples, i.e., 2 tapeworm species (Taenia sp. and Hymenolepis diminuta), 1 trematode (Opisthorchis sp.), and 5 nematodes (Ascaris lumbricoides, Trichuris trichiura, Strongyloides stercoralis, trichostrongylids, and hookworms). Six species of intestinal protists were identified, i.e., Blastocystis hominis, Cyclospora spp., Endolimax nana, Entamoeba histolytica/E. dispar, Entamoeba coli, and Giardia lamblia. Questionnaires and interviews were also conducted to determine risk factors of infection. These analyses together with a prevailing infection level suggested that most of villagers were exposed to parasites in a similar degree due to limited socio-economic differences and sharing of similar practices. Limited access to effective public health facilities is also a significant contributing factor.