Showing papers in "Journal of Helminthology in 1982"

A key for the identification of genera of the nematode family Trichostrongylidae Leiper, 1912

Abstract: The nematode family Trichostrongylidae is divided into six subfamilies Trichostrongylinae, Libyostrongylinae, Haemonchinae, Cooperiinae, Ostertagiinae and Graphidiinae which are briefly reviewed. The key is based mainly on specimens examined by the authors and includes one genus in the Trichostrongylinae, three genera in the Libyostrongylinae, six in the Haemonchinae, seven in the Cooperiinae, 17 in the Ostertagiinae and two in the Graphidiinae. Pseudostertagia, Pararhabdonema, Parostertagia, Obeliscoides and Travassosius are briefly described, figured and considered as genera of uncertain affinities. Nine genera, namely, Moguranema, Neocooperia, Bergheia, Mazamastrongylus, Paramecistocirrus, Ostertagiana, Ostertamia, Graphidiella and Trichostrongyella, specimens of which have not been available to the authors for examination, are listed giving details of host, habitat and geographical location, together with a summary of the diagnostic characters as described by the original authors.

Filaricidal properties of a wild herb, Andrographis paniculata

Abstract: Water decoction of the leaves of Andrographis paniculata killed in vitro the microfilaria of Dipetalonema reconditum in 40 min. Three subcutaneous injections of the extract into infected dogs at 0.06 ml per kg body-weight reduced the number of microfilariae in blood by more than 85%. The larvae were not totally eliminated with more infections but the reduced microfilarial level persisted. No toxic effect of the extract was observed in rabbits. The treated dogs became lethargic initially for a week, probably due to the mass killing of microfilariae.

Attempts to establish infections with Strongyloides stercoralis in mice and other laboratory animals

Abstract: Infection of a dog with Strongyloides stercoralis filariform larvae resulted in a persistent infection. Patent infections were not seen in rabbits, guinea-pigs, rats and 11 inbred strains and one outbred strain of mice. Manipulation of factors known to influence S. ratti infections in mice, such as age and sex of the host and the route of larval presentation, did not facilitate the appearance of rhabditiform larvae in the stools. Administration of immunosuppressive doses of corticosterioids to rabbits, guniea-pigs and C57Bl/6 mice did not permit complete development. Similarly, th course of infection was not altered in T cell-deficient hypothymic (nu/nu) mice. The fate of filariform larvae applied to the skin of mice was ascertained; filariform larvae were observed to migrate from the skin via the lungs to the muscles within several days of infection. Although S. Stercoralis does not develop to maturity in the small intestine of mice, this system does allow in vivo studies of the actions of anthelmintics against filariform larvae as well as a number of aspects of the immune response to this parasite.

The pathogenesis of a single challenge dose of Haemonchus contortus in lambs under six months of age.

Abstract: The pathogenesis of H. contortus infection in lambs under 6 months of age challenged orally with 10,000 third stage infective larvae is described. The development of the parasite and its relationship to haematological and pathological changes are discussed, with particular reference to specific cellular mobilizations, and detailed descriptions are given of the haematology and parasitology, gross pathology and histopathology at 4, 7, 12, 18, 22 and 35 days after infection. Dramatic changes had developed by day 12.

Immunization of calves against the microfilariae of Onchocerca lienalis.

Abstract: Three Jersey bull calves were immunized by subcutaneous injections of sonicated Onchocerca lienalis microfilariae suspended in phosphate buffered saline, and three control animals were injected with medium only All calves received booster injections 27 days later, and were challenged with live microfilariae 44 days after the booster Following challenge, only the immunized animals developed an elevated level of circulating eosinophils When necropsied ten days after challenge there was a 97% reduction in recoveries of microfilariae from immunized animals compared to challenge controls In human onchocerciasis it is the microfilariae which are the principal cause of pathology, and we believe that studies on O lienalis in both the natural bovine host and in inbred rodents provide a promising model to investigate immunity to Onchocerca microfilariae

Behaviour and enzyme release by Anisakis sp. larvae (Nematoda: Ascaridida)

Abstract: Anisakis sp. larvae when incubated in vitro produced secretions/excretions which released the dye from an azocoll substrate, indicating protease activity. The optimal conditions for enzyme release and activity were a temperature of 37 degrees C and a pH of 7.5. In addition the larvae showed peak behavioural activity at 37 degrees C, the body temperature of the final, marine mammalian host. The results are discussed in relation to their possible significance to the invasion of the various hosts in the life-cycle.

Description and population dynamics of Dactylogyrus legionensis n.sp. from Barbus barbus bocagei Steind.

Abstract: Dactylogyrus legionensis n. sp., a monogenean parasite from the gills of Barbus barbus bocagei from the Esla river (Leon, NW Spain), is described and its population dynamics discussed. It differs from the closely related species, D. balistae, in the presence of vaginal armour and in the morphology of the copulatory organ. D. legionensis was found on 30·40% of barbel, with a mean intensity of 13·71 and maximum infection levels in autumn-winter. The prevalence and intensity of infection rose significantly with the age and length of the barbel, and were higher in females than in males. D. legionensis showed preference for the second and first gill arches, sector III and the internal zone of each hemibranch.

Schistosoma mansoni: the presence and ultrastructure of vitelline cells in adult males.

Abstract: The presence of vitelline cells in male Schistosoma mansoni from both mixed ans single sex infections in mice is described. Ultrastructurally these vitelline cells resemble the mature, Stage 4 cells from normal female worms. As yet no developing vitelline cells (Stages 1 to 3) have been found. The cells do not appear to form complete lobules as in the female.

Ascaridoid nematodes of South American mammals, with a definition of a new genus.

Abstract: Ascaridoid nematodes occurring in South American mammals are divided into categories based on their possible origin. The affinities are discussed of five species so far known only from the Neotropical Region. Toxocara alienata (Rudolphi 1819) is reported from Nasua rufa socialis, Procyon cancrivorus, and Tayassus torquatus. The specimens from T. torquatus are described and found most closely to resemble Toxocara mackerrasae from south-east Asian and Austrialian rodents. Anisakis insignis from Inia geoffrensis is transferred back to Peritrachelius Diesing, 1851, on account of the structure of the lips and spicules. P. insignis is shown to exhibit remarkable convergence of lip structure with Lagochilascaris turgida from Didelphis marsupialis. Galeiceps longispiculum (Freitas & Lent, 1941) from Pteronura brasiliensis is confirmed as a species distinct from G. cucullus (Linstow, 1899) and G. spinicollis (Baylis, 1923), but G. simiae (Mosgovoy, 1951) is considered to be a synonym of G. spinicollis. An error in the host record of G. spinicollis is corrected from Cercopithecus leucampyx kandti to Lutra maculicollis kivuana. Ascaris dasypodina Baylis, 1922 from armadillos, including Cabassous unicinctus and Tolypeutes matacos, is redescribed and placed in a new genus Bairdascaris. The question is raised as to whether some species in Lagochilascaris, Galeiceps, and Toxocara may have crossed directly by sea from Africa to South America, rather than entering via North America.

The occurrence of Strongyloides ratti in the tissues of mice after percutaneous infection

Abstract: The migration of infective larvae of Strongyloides ratti has been examined in C57B1/6 mice after percutaneous infection of the anterior abdominal wall. Lateral migration of larvae through the skin and subcutaneous tissues was not seen. Large numbers of larvae were recovered from the muscles between 2 and 24 hours after infection and larvae were seen in the cerebrospinal fluid 24 and 48 hours after infection. Insignificant numbers of larvae were seen in the blood, serosal cavities, liver, spleen, kidneys, brain or nasopharynx. Larvae arrived in the lungs between 24 and 72 hours after infection and worms were first noted in the small intestines at 48 hours. It is concluded that larvae migrate preferentially to the muscles and CSF before passing to the lungs, but the exact mode of travel is uncertain.

Identification of some common infective filarial larvae in Malaysia.

Abstract: Infective larvae of Wuchereria, Brugia, Breinlia, Dirofilaria and Setaria species from an experimental vector, Aedes togoi, are compared. The distinctive bubble-like caudal papillae of Wuchereria bancrofti are readily distinguishable from the protuberant ones of Brugia spp; the ‘ear-like’ papillae of Breinlia are distinct from the ‘knob-like’ ones of Dirofilaria or the ‘thorn-like’ terminal papilla of Setaria.

Scanning electron microscopic observations on the tegumental surfaces of two rumen flukes (Trematoda: Paramphistomata)

Abstract: The surface microtopography of Calicophoron papillosum (Stiles & Goldberger) and C. calicophorum (Fischoeder), inhabiting the rumen of sheep, has been studied by SEM. In C. papillosum, conspicuous transverse ridges encircle the mid-body, gradually lessening dorsally towards the posterior end. The general body surface is aspinose and smooth except for minute bead-like tubercles in the circumoral area. Two types of putative sensory structures—domed aciliate papillae and tegumental pits—are present. Their characteristic aggregation in certain regions and their distribution in other parts of the body is described. A unique pattern of ridges, confined only to the base of the genital papilla and the genital atrium, has been observed. In C. calicophorum, tegumental folds encircle the body, these are more numerous near the anterior end and fewer posteriorly. The oral area has numerous concentric folds with domed aciliate papillae; between or on the papillae are tegumental elevated pits from the centre of which a knob-like structure protrudes. These sensory structures occur to a lesser extent in the acctabular area.

Schistosoma mansoni: the survival and reproductive status of mature infections in mice treated with oxamniquine.

Abstract: A single oral dose of 50 mg/kg of oxamniquine administered to mice with mature infections of Schistosoma mansoni gave rise to a hepatic shift and almost total elimination of the male worms. Regression of the reproductive system and a conspicuous reduction in size took place in the residual females which eventually resembled sexually immature adults. A second dose of oxamniquine had no apparent effect on these females within a period of 28 days following this treatment and it is suggested that this change in reproductive status is the result of discontinued male stimulation.

Habitat specificity of the acanthocephalan Acanthocephalus clavula (Dujardin, 1845) in eels Anguilla anguilla (L)

Abstract: The habitat specificity of the acanthocephalan Acanthocephalus clavula in the alimentary tract of eels was studied in natural infections and in fish maintained experimentally under different regimes. The parasite exhibited a preference for a particular region (55 to 65%) of the alimentary canal which did not differ in different species of host, but habitat specificity was not very precise as there was considerable variation between individual hosts and A. calvula was capable of surviving and maturing in all regions of the intestine. The mean position of males was slightly anterior to that of females, and the over-all sex ratio was in favour of females. At high levels of infection the range of the parasites was extended and the means position was significantly more anterior when compared to single worm infections. The parasite remains in the same site throughout the course of an infection: there was no posterior migration and gravid females occurred in the same proportion in all regions of the intestine. The mean position of the parasite did not change when the host was starved, or maintained in 100% sea water or with reduced aeration or at high temperature. The results were compared with the habitat specificity exhibited by other species of freshwater fish acanthocephalans, and it was concluded that A. clavula was as adaptable and hardy as its present host, the eel.

The infectivity of microfilariae of Brugia pahangi of different ages to Aedes aegypti.

Abstract: By transferring microfilariae of Brugia pahangi which had been born over a 24-hour period in the peritoneal cavities of jirds (Meriones unguiculatus) to the blood circulation of other jirds, infections of known age were tested for their ability to develop into third-stage larvae (L3) in mosquitoes Aedes aegypti. Microfilariae less than three days old were not able to develop to L3. Microfilariae which had been in circulation for three days to six months were capable of developing if ingested.

Pathophysiology of Mesocestoides corti infection in the mouse

Abstract: Liver histology and serum enzyme and protein changes were studied in two strains of mice showing different initial susceptibilities to infection with Mesocestoides corti. The results show an increase in ALT and AST levels during the period of invasion and proliferation in the liver and a decrease in the levels of these two enzymes following encapsulation of the parasite in the liver and liver regeneration. A progressive loss of albumin was accompanied by increases in the levels of the beta- and gamma-globulins. These changes are discussed in the light of our knowledge of the effects of this parasite upon its host.

Nematospiroides dubius in the jird, Meriones unguiculatus: factors affecting the course of a primary infection

Abstract: This project investigated the influence of the age and sex of the host and the level of infection with Nematospiroides dubius on the establishment and duration of a primary infection in the jird. It was found that 30 to 35% fewer worms matured in jirds than in mice and that this proportion was unaffected by the level of infection or by the sex of the host. In contrast the age of the jird was found to be critically important in determining the number of adult worms recovered 14 days after infection. Thus, maximum susceptibility to infection was observed when jirds were 18 to 22 days old. In older jirds susceptibility declined until 30 days after birth and thereafter, when approximately 70% of the infective larvae matured (relative to the number of worms maturing in mice). The duration of a primary infection in jirds was similar in both sexes but was influenced by the level of infection and by the age of the host at infection. Heavier infections (500 larvae) lasted about 10 days longer than low level infections, and expulsion of the parasite occurred even when the host was infected with only five larvae. The duration of a primary infection was markedly prolonged in neonatal jirds, faecal egg counts remaining positive for 54 to 56 days after infection of 12-day-old jirds. These results supply some further baseline data for future work on the biology of N. dubius in the jird and they provide support for the involvement of immunological processes in the termination of primary infections of this parasite in mature jirds.

Macrophage-mediated damage to filarial worms (Dipetalonema setariosum) in vivo

Abstract: An adult female Dipetalonema setariosum (Monnig 1926) recovered from the pleural cavity of Meriones libycus and bearing an adherent cell mass was examined by means of electron microscopy. The host reaction consisted exclusively of macrophages and was associated with disruption of the cuticular membrane and invasion of the cuticle itself. There was no evidence of prior activity by other cell types. Initiation of damage appeared to be associated with the release of lysosomal enzymes by the macrophages. Within the reaction a localized breaching of the cuticle had occurred and cells had penetrated the internal tissues of the worm. It is suggested that macrophages may play a role in the elimination of effete worms from an established population.

The effect of controlled release copper sulphate and tributyltin fluoride on the mortality and infectivity of Schistosoma mansoni cercariae.

Abstract: Mortality and infectivity or Schistosoma mansoni cercariae were tested against various concentrations of controlled release copper sulphate (EC-8) and tributyltin fluoride (CBL-9B). The results indicate that survival of cercariae varied with concentrations of molluscicide and times of exposures. Statistical analysis reveals that LC50 and LC90 for EC-8 were 1.18 mg/l/hour and 1.82 mg/l/hour while LC50 and LC90 for CBL-9B were 16.8 microgram/l/hour and 21.7 microgram/l/hour respectively. Sublethal concentration of both molluscicides reduced cercarial infectivity considerably. The doses of 0.25 to 0.5 microgram/l/hour for EC-8 and 2.0 to 6.0 microgram/l/hour for CBL-9B were found to be sufficient to inhabit cercarial penetration of the host skin.

The prevalence of hydatid cysts in slaughtered cattle in Bangladesh.

Abstract: Of 10,362 cattle examined in Bangladesh, 4,368 (42.15%) harboured hydatid cysts. One to three-year-old cattle had the lowest (11.34%) and those over nine years old the highest (93.21%) infections. Organ involvement was as follows: liver 35.18%, lungs 32.02%, spleen 0.80%, heart 0.41%, kidney 0.25%, omentum 0.11% and both liver and lungs 31.20%. Fertile cysts occurred in 8.11%, sterile in 74.91%, calcified in 9.42%, suppurative in 6.04% and undeveloped in 1.51% of animals.

Experimental Trichinella spiralis infection in the ferret, Mustela putorius furo

Abstract: Laboratory ferrets (Mustela putorius furo) were each inoculated with 500 larvae of a strain of Trichinella spiralis that had been passaged in mice for many generations. The recovery of adult worms from ferrets on Days 4 and 7 of infection represented a mean of 32% of the inoculum, with most of the worms being in the anterior three quarters of the small intestine. Larvae subsequently became encysted in the ferret musculature, with the diaphragm alone yielding as many as 5,750 larvae upon digestion. For comparative purposes, mice were each inoculated with 200 T. spiralis from the same batch of larvae. The recovery of adult worms from mice represented a mean of 54% of the inoculum. An abrupt decline in worm population, typical of infections in the mouse, was observed in both mouse and ferret hosts; in neither species had the decline begun on Day 7 of infection, but it had clearly begun by Day 11 and was essentially ended by Day 14.

The nature of antigens common to both the metacestodes of Taenia crassiceps and its laboratory host

Abstract: Metacestodes of Taenia crassiceps were cultured in laboratory rats and mice, washed in glycine/hydrochloric acid (Gly/Hcl) buffer pH 2.4 and phosphate buffered saline (PBS) pH 7.2 and a soluble extract of the metacestodes (SEM) was prepared from larvae washed in both buffers. The SEM and the original washings were examined for host IgG and a common host antigen (CHA). CHA was present in both the SEM and washings but IgG only in the washings and, in metacestodes from mice only in the Gly/HCl washings). Metacestodes washed in Gly/HCl were not viable. Metacestodes were also maintained in vitro in a peptide nutrient agar and 0.9% saline at 37 degrees C and a SEM was prepared from these; metacestodes from mice had neither host IgG nor CHA but those from rats had CHA but not IgG. SEM prepared from 'normal' metacestodes showed that the CHA consisted of at least two entities, only one having a common identity with the IgG. These results suggest that molecules of both host IgG and a common host antigen are present on the tegument of these parasites.

The morphology of Dentostomella kuntzi (Nematoda: Oxyuroidea) from Egyptian rodents.

Abstract: Dentostomella kuntzi is redescribed from specimens found in the rodent hosts Acomys cahirinus, Arvicanthis niloticus and Rattus rattus from the Giza province of Egypt, and compared with three species of the genus Dentostomella namely D. grundmanni, D. legerae and D. translucida. Unlike other species in the genus, the egg of D. kuntzi is operculate. The distribution of adult D. kuntzi within the intestine of Acomys cahirinus is also discussed.

Schistosoma intercalatum (Fisher, 1934) infection in sheep.

Abstract: Parasitological and clinico-pathological aspects of Schistosoma intercalatum infection in sheep were studied after exposure to 5000 cercariae per animal. It was shown that the infection, in spite of relatively high tissue egg counts, only gave rise to low-grade clinico-pathological manifestations with almost unaffected blood parameters. The parasites were mainly located in the lower part of the intestinal tract, and the number of eggs being passed in faeces was very low.

Prevalence of Angiostrongylus cantonensis infection in commensal rats in Bombay

Abstract: The prevalence Angiostrongylus cantonensis , a metastrongylid lungworm of rats, was investigated in three common species of rodents in the Greater Bombay area, namely, Rattus rattus, R. norvegicus and Bandicota bengalensis . In all, 737 R. norvegicus , 100 R. rattus and 100 B. bengalensis were examined and the presence of A. cantonensis infection was noticed in R. norvegicus (1·62%). About 800 slugs ( Laevicaulis alte ) were examined and were found to harbour third-stage larvae of Angiostrongylus .