The effect of praziquantel (PZQ) on the strobilar development of the cyclophyllidean cestode Mesocestoides corti was explored. Mesocestoides corti larvae were cultivated under conditions reported to favour their differentiation to the adult stage. Parasites were exposed to 0.1 μg ml-1 PZQ for 16 h and subsequently transferred to drug-free medium. The ocurrence of segmentation — an early event of the larval somatic differentiation to the adult worm — was considered as quantitative data. This phenomenon was evidenced earlier in worms transiently exposed to PZQ with respect to control cultures. Moreover, the rate of segmentation of drug-treated worms at the end of the experiment almost doubled that of control worms. To date, no similar effect on any cestode developmental process has been reported for an anthelmintic drug. In the light of the existing knowledge and understanding of PZQ mechanisms of action, the proposed experimental approach could contribute to the elucidation of pathways and mechanisms involved in cestode strobilar development.

In the past decade, interest has significantly increased regarding the medicinal and nutritional benefits of pomegranate (Punica granatum) peel. This study examined the effects of using pomegranate peel extract (PGE) alone and in combination with albendazole (ABZ) on ultrastructural and immunological changes in cystic echinococcosis in laboratory-infected mice. Results revealed that the smallest hydatid cyst size and weight (0.48 ± 0.47mm, 0.17 ± 0.18 gm) with the highest drug efficacy (56.2%) was detected in the PGE + ABZ group, which also exhibited marked histopathological improvement. Ultrastructural changes recorded by transmission electron microscopy including fragmentation of the nucleus, glycogen depletion, and multiple lysosomes in vacuolated cytoplasm were more often observed in PGE + ABZ group. IFN-γ levels were significantly increased in the group treated with ABZ, with a notable reduction following PGE treatment, whether administered alone or in combination with ABZ. Thus, PGE enhanced the therapeutic efficiency of ABZ, with improvement in histopathological and ultrastructural changes.

The species of the genus Dirofilaria are filarial parasites causing zoonotic infections in humans with an increasing incidence in temperate and tropical areas of the world. Due to its classification as a vector-borne disease, the most important factors influencing dirofilariosis transmission are those related to climate, such as temperature and humidity. However, other factors linked with human behaviour can influence the distribution of the parasite. Although the Russian Federation could be considered as a non-suitable area for Dirofilaria spp. transmission due to its climatic conditions, one third of the human cases of dirofilariosis have been declared in this country. Here, seroepidemiological data on human dirofilariosis for five different regions distributed throughout the Russian Federation (Rostov, Moscow, Ekaterinburg, Yakutia and Khabarovsk) were obtained. A total of 940 serum samples from totally random donors living in these areas were analysed by enzyme-linked immunosorbent assay for the detection of anti-Dirofilaria immitis immunoglobulin G antibodies. Similar seroprevalence data ranging from 3.41% in Yakutia to 6.95% in Khabarovsk, with no significant correlation with climatic data of yearly average temperature and rainfall from these regions were found. These results suggest that other factors probably related to human behaviour, and not only climatic conditions, might be facilitating the spread of human dirofilariosis in these areas.

An isolated population of 700 specimens initially described as Corynosoma strumosum (Rudolphi, 1802) Lühe, 1904 and currently reassigned to Corynosoma neostrumosum n. sp. was collected from one young male Caspian seal, Pusa caspica (Gmelin) in the southern land-locked Caspian Sea in April 2009. Collected worms were morphologically unique compared with those reported by other observers in open waters, especially in shape and distribution of proboscis hooks and trunk spines, dorso-ventral differences in proboscis hooks and their organization, the baldness of anterior proboscis, consistently smaller size of trunk and testes, larger eggs, the rough egg topography, epidermal micropores, and variations in the female gonopore. Molecular data from the internal transcribed spacer region of rDNA and the mitochondrial cox1 gene was also provided to supplement the morphological study of the new species.

5-Hydroxytryptamine (5-HT) (1, 2 and 5 mM) significantly stimulated the incorporation of radioactive inorganic phosphate (32Pi) into phosphatidylinositol, phosphatidyiethanolamine, phosphatidic acid and also total phospholipid fraction of Hymenolepis diminuta after one hour of incubation. Such effect was both time and concentration dependent. In the presence of 5-HT early labelling of phosphatidylinositol was observed. Also, the percentage stimulation by 5-HT was the highest in this fraction under all experimental conditions. The inorganic, organic, total and phosphatidylcholine-bound phosphate of H. diminuta incubated with 5-HT were not significantly different from those of the control under all incubation conditions. Results reported herein suggest that messenger molecules that are derived from phosphoinositides may be involved in the stimulatory mechanism of 5-HT in H. diminuta.

Resistance to challenge infection with Trichostrongylus colubriformis was studied in an outbred strain of guinea-pigs. Resistance was conferred by previous infections of 50 or 100 infective larvae and by intraperitoneal, intramuscular and subcutaneous administration of dialysed transfer factor prepared from guinea-pigs infected with T. colubriformis, by intraperitoneal administration of transfer factor prepared from the blood of sheep infected with T. colubriformis and on one of three occasions using transfer factor prepared from guinea-pigs which had not been infected with T. colubriformis. No significant resistance was transferred by administration of antigen prepared from adult T. colubriformis, or by non-dialysed transfer factor, or by dialysed transfer factor prepared from T. colubriformis-infected guinea-pig tissue which had been stored for several months at −20°C.

Studies were made of the fate of irradiated cercariae of Schistosoma mansoni, during their migration as schistosomula in the definitive host, by direct recovery of intact schistosomula from the skin and lungs and of adult worms from the liver of infected mice. Gamma radiation (6000 r) inhibited the migration and maturation of S. mansoni schistosomula to the adult stage. Penetration of irradiated cercariae into host skin proceeded normally and the first site of damage was in the lungs, but the majority of irradiated schistosomula were probably destroyed in the liver. The efiects of gamma radiation compared with those of ultra-violet radiation on cercariae of S. mansoni are discussed.

Breinlia mackerrasae n.sp. is described from the short-nosed bandicoot Isoodon macrourus. It bears most similarity to B. dentifera, but differs in having larger spicules and in the arrangement of the anal papillae. Female worms from a ‘mumut’ (Peramelidae) are described, but as no males are available, their taxonomic status remains uncertain. These are the first records of Breinlia from peramelid marsupials.

Although the efficacy of triclabendazole treatment against Fasciola gigantica has been shown before in cattle and buffaloes, there appears to be no published report on the efficacy of triclabendazole in impala or other antelope species. As part of a health monitoring programme at Mulungushi International Conference Centre, Lusaka, Zambia, a coprological examination was undertaken to investigate the helminthological status of captive impala (Aepyceros melampus). Of 39 fresh coprological samples, 46% contained F. gigantica. The source of infection was identified to be a fountain within the grounds of the conference centre. Lymnaea natalensis, collected from the study site, were induced to shed cercariae, and were thus confirmed as the snail intermediate host. In managing this disease, triclabendazole at 6 mg/kg was administered together with the feed bait. Water from the pond was drained; vegetation within it cleared and the pond allowed to dry for 1 week before water was replaced. Three weeks post-treatment, faecal examination revealed that the Fasciola had been cleared. To the best of our knowledge, this is a first case of Fasciola spp. infection reported in captive wild impala in Zambia and provides evidence that triclabendazole may be delivered to free-ranging antelope using medicated bait.

Schistosomiasis is the second major parasitic disease in the world after malaria. It affects 201.5 million cases in Africa alone. The aim of this research was to explore alternative vaccination strategies against experimental schistosomiasis mansoni. We assessed the effect of cercarial transformation fluid (CTF) singly and in combination with crude cercarial antigen (CCA) using alum as an adjuvant. The combined antigens gave the best results, as evidenced by a significant reduction in the worm load (62.07%), tissue egg count (78.16%, 86.46%) in liver and intestine respectively, and hepatic granuloma size (29.96%). Scanning electron microscopy revealed changes in the tegument, in the form of roughness and appearance of vesicles and furrows between the tegumental tubercles. Also, resorption of the ventral sucker and dimples replacing its spines were observed. The female tegument was irregular and its posterior end showed loss of spines and sensory bulbs. Moreover, there was a significant decrease in liver enzymes (alanine transaminase (ALT) and aspartate transaminase (AST)) compared to infected control mice. A significant elevation in CD4+T-lymphocytes, denoting amelioration of the immune status, in mice that received combined antigens was also observed. It can be concluded that combined antigens demonstrate potential as a vaccine against Schistosoma mansoni.

The long-term infection with Schistosoma mansoni (Gezira strain—Sudan) was studied in the Nile rat (Arvicanthis niloticus) to investigate the ‘self cure’ phenomenon. The results indicated that while a considerable number of worms and eggs were still recovered by week 28 post-infection, elimination of some of the worms occurred by week 20.

Four species of adult cestodes and one larval form were recovered from Rattus assimilis (Gould, 1858) from Queensland. Hymenolepis diminuta Rudolphi, 1819; and the cysticercus of Taenia taeniae-formis (Batsch, 1786) are new host records for Australia; the same infestations with Raillietina (Raillietina) celebensis (Janicki, 1902) have also been recorded by Baer and Sandars (1956). Two new species, viz:—Choanotaenia ratticola and Hymenolepis australiensis are described.

The type specimens are lodged in the Queensland Museum, Brisbane. Cotype and other specimens studied are also lodged in the Queensland Museum and in the Institut de Zoologie, Université de Neuchâtel, Switzerland; the Department of Parasitology, London School of Hygiene and Tropical Medicine and in the British Museum (Natural History).

C-banding has been performed on Dictyocaulus filaria using both original and modified techniques. The karyotype is reported based on C band observations. The existence of large heterochromatic blocks appears to be the cause of the low chiasmata frequency.

The taxonomic histories of Spirometra and Lueheella are reviewed, and the former is shown to be a junior synonym of the latter. Gatesius probably has priority over both. It is suggested that the International Commission on Zoological Nomenclature be petitioned to exert their Plenary Powers to validate Spirometra and invalidate Lueheella and Gatesius.

The fourth-stage larvae and adults of Ascaris suum were studied as they developed in the pig intestine from 11 to 22 days after infection. This is a period of rapid growth, in which both sexes increase approximately ten-fold in body length. Further examination of females showed the length increase to be positively allometric with respect to body diameter. The genital primordium in early fourth stage is at the same relative position along the length of the body as it is in the newly hatched larva. During development from fourth stage to adulthood the greater growth of the posterior part of the worm causes the relative position of the developing vulva to shift anteriad.

The normal ultrastructure of the abomasal fundic glands in sheep is described and compared with those of sheep infected experimentally with T. axei. Alterations were observed in mucous, mucous neck and zymogen cells and the results are compared with a similar study in normal and infected calves.

1. The influence of diets having different protein values on the schistosomicidal effect of Ambilhar has been investigated in mice.

2. Mice placed on these diets throughout the period of infection and then treated, reached differently. Low protein diets produced fewer and smaller worms which were more susceptible to the drug.

3. Mice maintained on an adequate diet were shifted to diets of varying protein values a few days before treatment. In these, drug treatment was more satisfactory in animals fed the high protein regimen.

4. Female worms were more affected by drug treatment than the males.

The difference in the final shape of the cyst of H. rostochiensis and H. schachtii is shown to be due to patterns of growth during cyst development. The greatest change of form takes place during the first 6 days for H. rostochiensis and the first 12 days for H. schachtii. The principal difference between the cyst shape in the two species is due to the greater increase in length in relation to breadth of the growing H. schachtii cyst. Premature tanning, due to environmental factors, is shown to affect final cyst form.

Lyophilized eggs of Schistosoma mansoni, when incubated briefly with serum from infected mice, bind antibodies, as made evident by subsequent binding of flurorescein labelled anti-IgG or 125 I-labelled protein A. On the basis of these findings, a radioimmunoassay was devised which employs whole lyophilized eggs (500 or 250 eggs/serum sample) as antigenic particles and 125 I-labelled protein A as a probe for antibody binding. Only 10 μl of serum are required to obtain 90% of the maximal binding. Kinetic studies indicated that 70% of the maximal seropositivity develops in mice between five and six weeks after a light infection, reaches a maximum at eight weeks and fluctuates around a high plateau thereafter. Pre-incubation of the test serum with soluble egg antigen (sea) considerably inhibits antibody binding to the eggs, suggesting that SEA-like antigens participate in the reaction.