Histopathology of the lung and total IgE in serum were compared in toxocariasis and allergic asthma murine models using BALB/c and C57BL/6 mice. Infection with Toxocara canis resulted in both strains of mice in marked histological changes and increased levels of total serum IgE. The ovalbumin (OVA) sensitization/challenge treatment for the induction of allergic asthma resulted in similar histological changes in BALB/c and, to a less extent, in C57BL/6 mice. Serum IgE levels of OVA-treated C57BL/6 mice were low. Histological changes observed included perivascular infiltration with eosinophils and mononuclear cells, peribronchiolitis, alveolitis and mucus production. Although these changes in addition to increased IgE production did occur in T. canis-infected C57BL/6 mice they were more pronounced in BALB/c mice. Thus, BALB/c mice appear to be the most appropriate strain of mice to perform studies on the possible connection between infection with T. canis and allergic asthma.

The population biology of the fish acanthocephalan Acanthocephalus clavula was described from 161 wild brown trout, Salmo trutta sampled over a two-year period in Clogher Lake in the west of Ireland. Overall prevalence of the parasite was 86% and the mean abundance was 53 worms per fish. Despite the presence of large numbers of worms in the trout very few females (2%) attained full reproductive maturity. This suggests that trout is an accidental host. A sample of yellow eels, Anguilla anguilla was examined at a different time from the same lake. The prevalence of A. clavula was 97% and the average abundance was 8 worms per fish. In contrast to the situation in trout, the proportion of female worms attaining full reproductive maturity was 61% fulfilling the expected characteristic of a preferred definitive host. The possible explanations for the very high abundance of A. clavula in trout are discussed and include the influence of fluctuations in host populations, host diet and the absence of a potential competitor.

The monoclonal antibody IACR-CCNj.3d has previously been used to isolate a gene (gp-col-8) with strong similarity to cuticular collagen from a mixed stage Globodera pallida cDNA expression library. The antibody has also been shown to label specifically the amphidial canal of pre-parasitic second stage juveniles (J2) of several plant nematode species without any reactivity on the cuticular surface, indicating that this protein is either not present or is inaccessible on the cuticular surface. This paper investigates the cross-reactivity of Mab IACR-CCNj.3d with Meloidogyne arenaria and the localization of the putative collagen protein on the cuticular surface of parasitic stages in planta and on the cuticular surface of juveniles inside eggs. The antigen was shown to be present in all developmental stages of the two species of potato cyst nematodes and M. arenaria. The antibody bound strongly to the amphidial canal and hypodermis of pre-parasitic J2 and adult females. The antigen was present on the cuticular surface of the sausage-shaped J2 in planta and of first stage juveniles (J1) inside the eggs. The presence of collagen on the surface of the cuticle of moulting stages of plant parasitic nematodes has been observed for the first time. It is clear that this protein has a role in the construction of the cuticle of the first stage juveniles and parasitic second stage juveniles, during moulting inside the eggs and in the root tissue, respectively.

Because of the natural adaptation of Mexican sheep, the aim of the present study was to identify the presence or absence of gastrointestinal parasitic nematodes (GIN) resistant to benzimidazole (BZ) in both Chiapas and Pelibuey sheep breeds on local farms. Both male and female GIN-infected grazing sheep of the two breeds were selected. Sheep faecal samples were collected to obtain infective larvae (L3). This evolving stage of the parasite was used for taxonomic identification of the genus, based on its morphological characteristics. BZ anthelmintic resistance was evaluated using a nematode–compound in vitro interaction bioassay and the allele-specific polymerase chain reaction technique to detect mutations of residues 198 and 200 on isotype 1 of the β-tubulin gene. Three BZ-based compounds (febendazole (FBZ), tiabendazole (TBZ) and albendazole (ABZ)) at concentrations of 1, 0.5, 0.25, 0.125, 0.062 and 0.03 mg/ml were used to estimate the anthelmintic efficacy and lethal dose (LD50, LD90 and LD99) of the drugs. Two parasitic nematodes, Haemonchus and Teladorsagia, were identified in both isolates. Also, the proportions of anthelmintic resistance identified in GIN of the two sheep breeds were 68% in isolates from the Chiapas breed and 71.8% in the Pelibuey breed. The specific lethal activity obtained with FBZ was higher than 90%. However, TBZ and ABZ showed a lethal activity lower than 50%. High variability in the discriminating dose values was found among the BZ drugs. For example, FBZ LD ranged from 0.01 to 1.20 mg/ml; on the other hand, TBZ and ABZ required a dose ranging from 0.178 to 759 mg/ml. In addition, amino acid changes of Phe (TTC) to Tyr (TAC) at codon 200 of the β-tubulin gene, showing resistance to BZ, and no changes at codon 198 Glu (GAA) to Ala (GCA) were observed for both isolates. These results confirmed the presence of a genetic mutation associated with BZ in both Chiapas and Pelibuey nematode isolates.

Karyotypes of three dilepidid species: Molluscotaenia crassiscolex, Anomotaenia bacilligera and Dilepis undula, which have not been recorded previously, were studied using conventional Giemsa staining and comparative karyometric analysis. Twelve small biarmed chromosomes were observed in mitotic cells of M. crassiscolex, 16 biarmed chromosomes of gradually decreasing size were found in cells of A. bacilligera, while 18 elements were characteristic for D. undula. These data, together with information available in literature, prove the heterogeneity and possible polyphyletic nature of the family Dilepididae.

The genus Megalobatrachonema is a rare group of nematode parasites within Ascaridida. The systematic status of Megalobatrachonema in the superfamily Cosmocercoidea (Ascaridida) has long been controversial. The relationship of Megalobatrachonema and Chabaudgolvania remains unsolved. In the present study, a new species of Megalobatrachonema, M. hainanensis sp. nov., was described based on specimens collected in Amolops hainanensis (Boulenger) and Hylarana spinulosa (Smith) (Amphibia: Anura) from Hainan Island, China. The large ribosomal DNA (28S) and internal transcribed spacer (ITS1-5.8S-ITS2) were also sequenced for molecular identification and phylogenetic study. Phylogenetic analyses using maximum likelihood (ML) inference and Bayesian inference (BI) based on 28S and ITS1 sequence data, respectively, supported that Megalobatrachonema is a member of the family Kathlaniidae. In addition, the genetic comparison and phylogenetic results based on ITS1 sequence data also supported that the genus Chabaudgolvania should be considered as a synonym of Megalobatrachonema.

In April 1934 Mr. W. E. H. Hodson, Advisory Entomologist, Reading University, sent the writer a portion of narcissus bulb exhibiting disease symptoms. The bulb was a trumpet daffodil, of the variety “Sir Watkin,” from a stock which had been growing in the Isles of Scilly for 40 years or more and had probably never been hot-water treated. It contained a number of nematodes belonging to the genus Aphelenchoides which differed in certain anatomical features from other members of this genus. Good specimens of the worm were not very numerous or favourable for detailed investigation but some measurements and drawings were made at the time and it was hoped that at a later date further and better supplies of the organism would become available. In July 1934 the same species of nematode was found in a portion of diseased narcissus bulb sent to the writer by Mr. L. N. Staniland, Advisory Entomologist, Seale-Hayne Agricultural College, Newton Abbot, when the same peculiarities of structure and appearance were again noted and found to be constant.

The history of the beet-strain of Heterodera schachtii in Germany, where it was first recognized in 1859, and its subsequent discovery in other beet-growing European countries and the United States of America, have already been described in some detail in a Memorandum published by the Imperial Bureau of Agricultural Parasitology. This Memorandum was published in 1931 with the object of emphasizing the potential danger of Heterodera schachtii to the sugar-beet industry, then comparatively newly established in Britain. Observations carried out in America are quoted, which strongly indicated that the eelworm was introduced into the United States by the use of seed imported from European countries where the infection was known to be intense and of long standing; this contention, however, does not yet appear to have been decisively proved. The danger of repeated beet cultivation, without regard to rotation of crops, was particularly emphasized with reference to the wide distribution of the potato-strain of H. schachtii in Britain, and such infections as were already known to occur on other host-plants were noted.

Biochanin A (BCA) is a multifunctional natural compound that possesses anti-infective, anti-inflammatory, anti-oxidative and hepatoprotective effects. The aim of the study was to assess the therapeutic efficacy of BCA on Schistosoma mansoni-infected mice. Fifty mice were divided into six different groups as non-infected, non-infected BCA-treated, infected untreated, early infected BCA-treated (seven days post-infection (dpi)), late infected BCA-treated 60 dpi and infected praziquantel (PZQ)-treated groups. Parasitological, histopathological examination and immunohistochemical staining of transforming growth factor (TGF)-β, inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX-2) were investigated in liver sections. Cytochrome P450 (CYP450) gene expression of S. mansoni was evaluated by quantitative real-time polymerase chain reaction (RT-qPCR). A single dose of BCA significantly reduced worm burden in early (82.14%) and late infection (77.74%), mean tissue egg load in early (7.27 ± 0.495) and late BCA administration (7.63 ± 0.435) and decreased granuloma size. CYP450 mRNA expression was significantly reduced in early BCA treatment as compared to late treatment which emphasizes that early administration of BCA had more pronounced effects on worms than late administration. Both early and late BCA administration led to significant reduction in inflammatory cytokines as TGF and iNOS. Although the reduction of TGF and iNOS in BCA-treated mice was superior to PZQ, no statistically significant differences were noted. However, a significant downregulation of COX2 was noted in hepatocytes as compared to both infected control and PZQ-treated mice. BCA has schistosomicidal, anti-inflammatory, antioxidant and anti-fibrotic effects and could be regarded as a potential drug in schistosomiasis treatment.

This paper embodies certain experiments on control of the nematode Aphelenchoides ritzema-bosi Schwartz, 1911, on chrysanthemums, and were started in September 1930 at the request of several commercial chrysanthemum growers in Staffordshire and Warwickshire.

It is only within the last few years that the various species of Bulbous Irises have been recognised as host of Anguillulina dipsaci. Despite the comparative paucity of information on the matter there is evidence of the likelihood of infestations becoming serious in the immediate future. It may, therefore, be of value to place on record such information as is at present available.

In the last years, a growing number of studies have focused on the search for biological indicators of human impact in freshwater environments. Given their susceptibility to different types of impact, larval digeneans have been considered as useful tools for the study of temporal variations in parasite communities. However, few studies have been carried out in lotic environments. For that reason, the spatio-temporal variations of the larval digenean assemblages parasitizing the gastropod Heleobia parchappii were analysed in four human-impacted streams, located on the coast of Argentina. In total, 4800 specimens of H. parchappii were collected seasonally, and 12 digenean species belonging to eight families were registered. Three of the streams showed similar species presence but, during spring and summer, the streams located within the city presented lower species presence than the streams located in the urban periphery. By contrast, the spatial prevalence values evidenced a higher variation between the environments. Streams located in the urban periphery showed higher prevalence values throughout the year, compared to those calculated for streams located within the city. The spatio-temporal variations of larval digenean assemblages parasitizing H. parchappii seem to be mainly influenced by the diversity and vagility of definitive hosts, the types of digenean life cycles and habitat characteristics. However, environmental disturbances derived from anthropogenic activities are highlighted as the probable main factors that may affect the composition and dynamic of these parasite assemblages.

A new scheme of clarifying clinical forms of toxocariasis is proposed to include: (i) systemic forms: classical VLM and incomplete VLM; (ii) compartmentalized forms: ocular and neurological toxocariasis; (iii) covert toxocariasis; and (iv) asymptomatic toxocariasis. The following markers are helpful in defining clinical forms namely, patient characteristics and history, clinical symptoms and signs, positive serology, eosinophilia and increased levels of IgE. Amongst the available drugs albendazole is the most commonly used, although other benzimidazole compounds have a similar efficacy. The recommended dose of albendazole is 15 mg kg-1 body weight daily for 5 days and in some cases with VLM syndrome the treatment needs to be repeated. An evaluation of treatment efficacy can be made by observing a rise in eosinophilia within a week followed by any improvement in clinical symptoms and signs, lower eosinophilia and serological tests taken over a period of at least 4 weeks. In addition to clinical rationales for the specific treatment of VLM and OLM, preventive treatment needs to be considered bearing in mind the increasing risk of larvae localizing in the brain during the course of an infection. To reduce migration of Toxocara larvae a single course of albendazole is suggested in cases where eosinophilia and serology are at least moderately positive.

Neurocysticercosis is a parasitic disease caused by encysted larvae of Taenia solium in the human central nervous system. Cysts mainly affect the cerebral hemispheres, although they can also be found in ventricles, basal cisterns, and subarachnoid spaces, and rarely in the cerebellum. Given the impossibility of studying the disease in human patients, Cardona et al. (1999) developed a mouse model of neurocysticercosis, using Mesocestoides corti, a closely related cestode. This allows us to study the parasite–host relationship and the mechanisms involved in the disease, in order to improve the therapy. In this murine model of neurocysticercosis, the location of tetrathyridia in parenchyma, ventricles and meninges has already been reported. The aim of this work is to report the cerebellum as a new location for M. corti tetrathyridia in the murine model of neurocysticercosis. A murine model that reproduces the human pathology is essential to evaluate the symptomatology and response to drug treatment in experimentally infected mice.

It is demonstrated that Schistosoma curassoni, a parasite of sheep, cattle and goats in parts of West Africa, will live for at least 8 years 5 months in a sheep. The sheep was exposed to 500 cercariae of S. curassoni liberated from infected Bulinus wrighti. The sheep died of natural causes, and at post-mortem 28 pairs of adult S. curassoni were removed from the mesenteric and rectal veins. All female worms were gravid, and eggs were hatched from faeces to produce miracidia. The development of immune responses of the host had apparently little or no effect on the viability of the eggs. Histological studies of the liver, small and large intestines revealed mild pathological symptoms. The longevity of S. curassoni is the first record of longevity of schistosomes to be based on worm counts.

An analysis was undertaken of intestinal helminth communities in flounder Platichthys flesus from two sites on the River Thames. A comparison was made between helminth community richness and diversity from these sites at the component and infracommunity levels. At the component community level, a richer and more diverse parasite community was found in flounder from the Tilbury location (marine influence) than that from the Lots Road location (freshwater influence). At the infracommunity level, more parasite species and parasite individuals per host were found at Lots Road and the percentage of similarity values were low at both locations. Helminth species with high prevalence values in the parasite communities of the flounder are the dominant species in any individual fish, harbouring multi-specific infections. The presence of more invertebrate species, which are intermediate hosts in the helminth life cycle in the Thames, fish vagility and the high prevalence and abundance values of Pomphorhynchus laevis in the flounder, may explain the differences between the two locations.

The ectoparasite fauna of two damselfishes, Stegastes nigricans and Dascyllus aruanus, from Moorea Island in French Polynesia was investigated. Gills of these damselfishes were infected with congeneric Monopisthocotylea Monogenea belonging to the genus Haliotrema. Stegastes nigricans were found to harbour a guild of three Haliotrema species whereas only one species inhabited D. aruanus. Microhabitat distribution, inter- and intraspecific competition and interspecific associations on the gill were studied. Observations on site preference revealed no spatial segregation between the three congeneric species inhabiting the gills of S. nigricans. Juvenile and adult monogeneans of that guild occurred on the same microhabitat. The dominant species Haliotrema sp. 1 did not expand on the microhabitat when the intensity of infection increased. Interspecific association tests revealed positive and negative associations. Haliotrema sp. 4 expanded its distribution on the gills of Dascyllus aruanus when the intensity of infection increased suggesting the likelihood of intraspecific competition. Juvenile and adult monogeneans of Haliotrema sp. 4 appeared to segregate as a result of intraspecific competition. This competition may exist to enhance resource availability when the gill habitat is limited. Overlaps between niche breadth and species microhabitat were revealed for monogenean species inhabiting S. nigricans. Interspecific competition did not appear to play an important role in the distribution of S. nigricans congeneric ectoparasites. Reinforcement of reproductive barriers may have led to the avoidance of hybridization.

Nematodes of the family Thelastomatidae are parasitic in the alimentary tract of many arthropods, including Periplaneta americana L. In Meerut, Uttar Pradesh, India, two nematode species, namely Hammerschmidtiella indicus and Thelastoma icemi, belonging to this family have been reported. In the present study, the molecular phylogeny of these two nematode species was derived using small subunit (18S) sequence and secondary-structure analyses. The small subunit sequence analyses were carried out to explore the validation and systematics of these species. Phylogenetic analyses were performed for primary sequence data as well as using neighbour-joining and maximum-parsimony approaches. In contrast, the inferred secondary structures for the two species, using free-energy modelling, showed structural identities. As well as this, motif sequences were also found to be a promising tool for nematode species identification. The study provides molecular characterization based on primary sequence data of the 18S ribosomal DNA region of the nematodes along with secondary-structure data and motif sequences for inferences at higher taxonomic levels.

Cysticercosis is caused by infections with embryonated eggs of the tapeworm Taenia pisiformis. Knowledge of the genetic characteristics of T. pisiformis could be applied to study the epidemiology and transmission of this parasite. In this study, 61 isolates of intraperitoneal cysticerci from eight geographically distinct regions in Sichuan province, China, were subjected to a molecular analysis in order to determine their intra-regional genetic characteristics. Partial sequences of the mitochondrial cytochrome c oxidase subunit I (cox1, 1427 bp) and NADH dehydrogenase 1 (nad1, 738 bp) were concatenated. Five haplotypes were identified, and 89.04% of total genetic variation was found in collections of T. pisiformis isolates from a single region. According to the phylogenetic reconstruction, the T. pisiformis isolates from eight regions did not form geographical clusters. Our study highlights the genetic characteristics of T.pisiformis with the aim of accelerating the genetic research and control of cysticercosis.

The rat tapeworm Hymenolepis diminuta can bioconcentrate several elements to conspicuously higher concentrations than tissues of their definitive host. The main aim of this study was to locate parts of the tapeworm into which lead, cadmium, zinc, copper, manganese and iron are accumulated. Male Wistar rats were experimentally infected with H. diminuta and worms were exposed to two different forms of lead for 6 weeks through the oral exposure of their rat hosts. After the exposure period, the element levels were determined in the posterior and anterior proglottids of the tapeworm. In all cases, lead concentrations were higher in the anterior parts than the posterior parts. Concentrations of cadmium, copper, iron, manganese and zinc were also significantly higher in the anterior parts. Zinc concentrations showed an opposite trend, with higher zinc levels detected in the posterior part of the strobila, in the control group. The present study demonstrates that risk and essential elements are accumulated mainly into the anterior part of H. diminuta.