Helminthologia最新文献

The health and production of small ruminants in constantly menaced by parasitic infections, especially those caused by the blood-sucking gastrointestinal nematode Haemonchus contortus. The aim of this study was to assess the structural cuticular changes in adult H. contortus induced by the use of extracts from local medicinal plants and to examine their ovicidal activity. Previous studies have confirmed the beneficial effect of herbal mixtures in preventing haemonchosis in lambs by lowering fecal egg production and improving immunocompetence. We exposed adult H. contortus to Herbmix (a mixture of medicinal plants) under in vivo and in vitro conditions for observation by scanning electron microscopy (SEM). For the in vivo observations, adult worms were isolated from the abomasa of experimentally infected lambs from a Herbmix group and a control group. Surface structure did not differ significantly between the exposed and control groups. The ovicidal activity of an aqueous Herbmix extract was assessed in vitro, establishing the inhibition of hatching with an ED₅₀ of 6.52 mg/mL. Adult worms for in vitro examination were isolated from experimentally infected lambs and incubated in Herbmix aqueous extracts for 24 h. SEM observations indicated that none of the worms had prominent ultrastructural changes on their cuticles. This study suggests that previously demonstrated antiparasitic effects of medicinal plants did not negatively affect adult parasites by damaging their external structures.

The Nurse cell of the parasitic nematode Trichinella spiralis is a unique structure established after genetic, morphological and functional modification of a small portion of invaded skeletal muscle fiber. Even if the newly developed cytoplasm of the Nurse cell is no longer contractile, this structure remains well integrated within the surrounding healthy tissue. Our previous reports suggested that this process is accompanied by an increased local biosynthesis of sialylated glycoproteins. In this work we examined the expressions of three proteins, functionally associated with the process of sialylation. The enzyme UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase (GNE) is a key initiator of the sialic acid biosynthetic pathway. The α-dystroglycan was the only identified sialylated glycoprotein in skeletal muscles by now, bearing sialyl-α-2,3-Gal-β-1,4-Gl-cNAc-β-1,2-Man-α-1-O-Ser/Thr glycan. The third protein of interest for this study was the enzyme β-galactoside α-2,3-sialyltransferase 6 (ST3Gal6), which transfers sialic acid preferably onto Gal-β-1,4-GlcNAc as an acceptor, and thus it was considered as a suitable candidate for the sialylation of the α-dystroglycan. The expressions of the three proteins were analyzed by real time-PCR and immunohistochemistry on modified methacarn fixed paraffin tissue sections of mouse skeletal muscle samples collected at days 0, 14 and 35 post infection. According to our findings, the up-regulation of GNE was a characteristic of the early and the late stage of the Nurse cell development. Additional features of this process were the elevated expressions of α-dystroglycan and the enzyme ST3Gal6. We provided strong evidence that an increased local synthesis of sialic acids is a trait of the Nurse cell of T. spiralis, and at least in part due to an overexpression of α-dystroglycan. In addition, circumstantially we suggest that the enzyme ST3Gal6 is engaged in the process of sialylation of the major oligosaccharide component of α-dystroglycan.

Taxonomic evaluations are needed to accurately determine the host selection of fish parasites. The present study is a multidisciplinary research in the field of basic and fish diseases sciences. The description of the hybrid species of Squalius orientalis and Alburnus derjugini and infection of Ligula intestinalis in these hybrid fish were reported for the first time from the Kürtün Dam Lake in northeast Turkey. A total of 450 fish were sampled in March, August, and October in 2020 using gillnets. Detailed morphological characteristics (n = 24) were compared to determine the difference among ancestors and hybrid species. The prevalence of L. intestinalis between the sampling periods and the size groups of fish (0 - 10, 11 - 15, and ≥16 cm in length) were examined. Moreover, the highest prevalence of the parasite was observed in October (78.94 %), with a size range of 0 - 10 cm in length (77.8 %). In addition, the total prevalence of the parasite was 48.44 %. The results revealed that most of the diagnostic metric and meristic features of hybrid fish were ranging between the data of S. orientalis and A. derjugini. According to previous reports, when hybrid individuals were compared with their ancestors in terms of prevalence, hybrid individuals were more susceptible to L. intestinalis infections. This study was unique as it provided the first record of L. intestinalis in a hybrid fish population.

A total of 357 Syngnathidae fishes (Syngnathus abaster Risso, 1827, S. typhle Linnaeus, 1758 and Hippocampus hippocampus (Linnaeus, 1758) caught in different habitats along Crimean Black Sea shelf were examined for presence of endohelminths and revealed to be hosts of 15 helminth species. The fishes are second intermediate hosts for five "birds'" digenean species and nematodes (larvae of three species and immature adults of one more species) completing life-cycles in waterbirds and fish; for two acanthocephalans and three cestodes larvae ending development in fish. We suggest, basing on data on feeding of the Black Sea predatory fish and waterbirds, that Syngnathid fishes are paratenic hosts in parasitic systems of most cestodes, nematodes and acanthocephalans. All the trematodes found are generalists at metacercarial stage; specialists Timoniella imbutiformis and Aphallus tubarium use Syngnathidae as definitive hosts. Cestodes, nematodes as well as acanthocephalans found are generalists, too. Based on infection indices, S. typhle are main final host and H. hippocampus are main 2nd intermediate hosts for T. imbutiformis; Syngnathids are accidental hosts for other trematodes as well as for all the cestodes, nematodes and acanthocephalans. Cryptocotyle concava and Pygidiopsis genata are important as Syngnathid fishes' threats, especially in marine protected aquatoria, being potential agents of "black spot disease".

The gray snapper Lutjanus griseus is a commercially important fish species along its distribution range in the western Atlantic Ocean. However, despite its importance, there is still little knowledge about its parasitic fauna for the Mexican coasts of the Gulf of Mexico. The aims of this research were to generate a list of the parasitic fauna present in juvenile gray snapper L. griseus from a coastal lagoon located in southeastern Mexico, to evaluate the infection levels of parasites and to determine the relationship between the abundance of parasites and the fish size and condition factor. Samples of L. griseus (12 - 29.2 mm) were obtained in two periods of the year (dry and rainy seasons) to examine the intra-annual variability of its parasitic fauna. A total of 17 parasite species were recorded belonging to six taxonomic groups (Myxozoa, Monogenea, Digenea, Cestoda, Nematoda and Acanthocephala). The highest levels of infection (abundance, prevalence and intensity of infection) were found for the monogeneans Euryhaliotrema griseus and Euryhaliotrema fastigatum. There were no significant correlations between the total abundance of parasites and the fish condition and size (total length) in not any of the two seasons studied, suggesting that the body size and the biological condition index of the host did not directly influence the abundance of parasites in early life stages of L. griseus. Moreover, the species of parasites found that could be zoonotic for humans through the consumption of raw or inadequately cooked fish were the nematodes Contracaecum sp. type 1, Contracaecum sp. type 2, Cucullanus pargi and Pseudoterranova sp. The presence of the monogeneans E. griseus and E. fastigatum was also highlighted because these ectoparasite species are known to cause harm to fish under culture systems. All the parasite species found in this study, except nematodes, were new records of geographic distribution.

Trichuris trichiura is a soil-transmitted helminth prevalent in developing countries with poor, inadequate sanitation and unsafe water sources. In Malaysia, the prevalence of trichuriasis is relatively high among the aboriginal community due to poverty and poor sanitation. However, there are few studies to determine the seasonal variation on the prevalence and risk factors to acquire Trichuris trichiura infection in Malaysia. The present study found higher Trichuris trichiura infection during the dry season (63.6%; 138/217) in comparison to the wet season (55.5%; 142/256). Low household income, low education level and practice of open defecation were significant risk factors to acquire Trichuris trichiura infection during the wet season. Usage of untreated water supplies for daily activities was a risk factor to acquire trichuriasis during the dry season. This study highlighted that poverty and poor sanitation practices as well as drinking untreated water put the aborigines at high risk to acquire trichuriasis. Therefore, health education, improved sanitation and provision of treated water supply are recommended for the prevention and control of Trichuris trichiura infections in the aboriginal community.

Trichinellosis is a nematode-causing disease distinguished by its continuous transmission in the carnivores and omnivores. Despite effective eradication of the enteral forms, conventional drugs fail to eliminate the migrating and muscle ones. Over the past years, researchers intensified the work on herbal medicines as alternatives or aids to albendazole, the reference drug. This research hypothesizes that the therapeutic agent absorption route could be an evidence-based carrier molecule or auxiliary drug to albendazole. Accordingly, this in vitro study was designed to investigate mainly the phenotypic changes induced by a mono-treatment of albendazole, Lipidium sativum (garden cress), and Commiphora molmol (myrrh). Incredibly, no data were reported on the morphological alterations of T. spiralis larvae treated by any of these drugs. The experimental design tested various concentrations (25, 50, 100, and 200 μg/ml) of each herbal medicine for the lethal effects on the parasite forms for a day (1, 12, and 24h). The data showed that the highest significant mortality rate of the parasite forms was in favor of the concentration 200 μg/ml of both plant extracts in a time-dependent manner. Therefore, albendazole at 200 μg/ml dose was tested in parallel, and all experimental groups were compared to non-treated muscle larvae and worms. Albendazole-treated worms accounted for the least significant (p<0.001) survival rate (2 %), followed by myrrh (5 %), and the adverse was valid for the survival rate of the muscle larvae at that time. None of the larvae/worms was alive after 24 hours of incubation with the 200μg/ml of either treatment. The scanning electron microscope investigation of the experimental groups provided a shred of evidence for different routes of taking up the candidate drugs by the parasite. In conclusion, the results of the previous work in vivo and current in vitro study recommend myrrh over garden cress as a complementary agent of albendazole.

The present study determined the prevalence of gastrointestinal (GI) parasites in small ruminants kept in smallholder farms in Phitsanulok, Northern Thailand. A total of 885 goats from 31 smallholder farms were selected randomly between May 2019 to January 2020. Fecal samples were collected to estimate fecal egg counts and oocysts counts using the modified McMaster technique. Furthermore, pooled fecal samples from each of the farms were cultured in order to differentiate third-stage larvae of nematode. Examination of fecal samples revealed that 885 were positive for one or more parasites, giving an overall prevalence of 87.2 %, of which 38.6 % were infected with one and 48.6 % with multiple parasite. Strongyles and Eimeria oocysts were the most prevalent. Haemonchus contortus and Strongyloides papillosus were the predominant species based on the percentage of larvae in fecal cultures. Tapeworm eggs were encountered in 14.2 % of all samples. No significant difference in gastrointestinal parasite prevalence was associated with sex of the host. Infection was significantly (P = 0.009) highest in poor body conditioned goats (72.0 %) as compared to moderate (48.9 %) and good body conditioned (50.0 %) goats. This report on prevalence of GI parasites of small ruminants in smallholder farms in Northern Thailand reveals a high endoparasitic infections that appeared well-adapted to environmental conditions. Further studies on endoparasite control are required to establish the impact of parasitism on productive performance, including monitoring control parasite programs are needed for better health and productivity.

We describe for the first time the transmission route employed by the parasitic larvae of the freshwater mussel Anodontites trapesialis (Lamarck, 1819) during cohabitation on the guppy Poecilia reticulata Peter, 1859. The freshwater mussel and fish-host were employed as a model system to investigate the infection and parasite establishment. Laboratory experiments included video recording and histopathological analysis of the infection. In vivo video observations demonstrated that lasidium larvae could be transmitted to guppies during direct contact. A series of histology samples and photography suggest that this larva attaches and colonizes possibly on-site on the outer surface of the fish, causing cellular inflammation in the epidermis layer with cellular hyperplasia in the zone of parasite attachment. An evident hyaline layer, cellular hypertrophy, and a large number of undifferentiated proliferating cells were observed. Hemorrhagic tissue and swelling were observed in the epidermis and dermic zone. The total number of larvae per male and female guppy was 525 ± 86 and 494 ± 167, respectively. No parasitic preference was detected for male versus female parasitized fish.

1,024 individuals of Hydrobioides nassa were collected from 12 different localities in eight provinces from north, west, and central regions of Thailand. The infection of parasitic trematodes was investigated using shedding and crushing methods to search for cercariae and metacercariae. Trematode infection was found at a relatively low prevalence of 5.57%. Five different morphological types of cercariae were detected; xiphidio, monostome, mutabile, ophthalmoxiphidio, and microcercous, and three different morphological types of unknown metacercariae were observed. Microcercous cercariae of the lung fluke genus Paragonimus is reported here for the first time in a bithyniid snail. Our current finding show that H. nassa can serve as intermediate host for a range of parasitic trematodes in Thailand.