bluuebunny/crossref_metadata_2025 huggingface dataset:
Chromosomes of Onchocerca volvulus (Spirurida:Onchocercidae): A comparative study between Nigeria and Guatemala
Authors: Hirai H. , Tada I. , Takahashi H. , Nwoke B. E. B. , Ufomadu G. O.
Published: June 2009

Chromosomes of Nigerian Onchocerca volvulus were compared with those of Guatemalan O. volvulus. Both parasites had basically the same chromosomal construct (2n=8, XY type). Autosomes consisted of a pair of large and two smaller pairs. Sex chromosomes were made up of medium sized X chromosome and very small Y chromosome. It was not possible to infer the position of the centromeres.
The neural commissural rings of the adult maleSchistosoma mansoni
Authors: Withyachumnarnkul B. , Pongsa-Asawapaiboon A. , Sobhon P. , Upatham E. S.
Published: June 2009

Adult males ofSchistosoma mansoniwere preincubated in 5-hydroxtryptamine (5HT) and processed through the glyoxylic acid fluorescence technique to visualize 5HT-containing neural elements. 5HT flourescence was seen as a series of cross-sectional rings beginning behind the ventral sucker toward the tail end. The rings were connected by two lateral nerve cords running longitudinally along the whole lenght of the worms.
Transmission of urinary schistosomiasis in Sukumaland, Tanzania. 1. Snail infection rates and incidence of infection in school children
Authors: Lwambo N. J. S.
Published: June 2009

Seasonal density fluctuations of Bulinus nasutus populations with accompanying Schistosoma haematobium infection rates in relation to rainfall and habitat water volumes were studied at Ukiriguru, Mwanza, Tanzania. Alongside the snail investigations, 50 school children initially negative for urinary schistosomiasis were examined regularly to determine seasonal incidence rates for the infection. Of the 17 646 B. nasutus collected in 2 years, 156 (0.88%) were found shedding cercariae. Snail populations fluctuated seasonally as influenced by rainfall through its effects on habitat water volume. Monthly snail infection rates ranged from 0.09% to 3.19% and were highest in February and March, at the time of the short dry period. Monthly incidence of S. haematobium in school children ranged between 2.6% and 12.5%, being highest in April and May. There was a significant linear association between monthly snail infection rates and S. haematobium incidence rates in school children ( in 1983/84) suggesting that the maximum transmission period for urinary schistosomiasis in the area occurs during the short dry period, sometime in February/March so that most of the infections in the community would be detected in April/May.
First report of Galactosomum ussuriense Oshmarin, 1963 (Trematoda: Heterophyidae) from the shore birds of Visakhapatnam, India
Authors: Mani G. G. , Madhavi R.
Published: June 2009

Adult trematodes identified as Galactosomum ussuriense Oshmarin, 1963 were recorded from the intestine of Sterna hirundo and Larus brunnicephalus from Visakhapatnam, India. The occurrence of metacercaria of this species in inshore and offshore fishes is discussed in relation to the ecology of the snail intermediate host.
The ecsoma in Hemiuridae (Digenea: Hemiuroidea): tegumental structure and function in the mesocercaria and the metacercaria of Lecithochirium furcolabiatum (Jones, 1933) Dawes, 1947
Authors: Matthews B. F. , Matthews R. A.
Published: June 2009

Ultrastructural, histochemical and autoradiographical techniques have been used to investigate the development and function of the tegument of both somal and ecsomal body regions in the hemiurid Lecithochirum furcolabiatum. The terms mesocercaria and metacercaria are here adopted for those stages in the copepod second and fish third intermediate hosts respectively on the basis of morphology and on analogy with the Strigeidae. Mesocercariae were obtained by experimental infection of the harpacticoid copepod Tigriopus brevicornis with the cystophorous cercariae (syn. Cercaria vaullegeardi), whilst metacercariae were removed from the body cavities of naturally-infected rockpool teleosts including Gobius paganellus and Blennius pholis. Observations on the mesocercaria show the origin of the ecsoma from the distal half of the excretory vesicle, which at 21 days post-infection is capable of eversion through the terminal pore. The nucleated microrugous surface layer of the ecsoma at this stage is modified or replaced in the metacercaria by anucleate syncytial tegument similar to that of the adult organ. The metacercarial stage is also associated with the more advanced development of the somal tegument. The two stages differ in metabolic activity, the somal tegument of only the metacercaria resembling that of the adult in acid phosphatase distribution. In the mesocercaria the ecsomal tegument showed the strongest uptake of 3H-tyrosine; absorption of the latter was not detected in the metacercaria. 3H-glucose uptake was restricted to the intestinal caeca of both stages.
Immunological analysis ofOpisthorchisandClonorchisantigens
Authors: Sirisinha S. , Sahassananda D. , Bunnag D. , Rim H. J.
Published: June 2009

Immunoreactive components ofOpisthorchis viverriniandClonorchis sinensiswere analysed by enzyme-linked immunosorbent assay (ELISA), radioimmunoprecipitation and immunoblotting. Somatic extracts from these two liver flukes as well as from other related parasites, together with the metabolic products, were tested for their reactivities with sera from patients with opisthorchiasis and clonorchiasis. A significant cross-reactivity in the ELISA was noted betweenOpisthorchisandClonorchis. Immunoblotting and radioimmunoprecipitation analyses showed that the 89-kD protein which was previously shown to be a predominant metabolic product ofO. viverrinireacted with sera from both groups of patients. However, an antigen with a molecular weight of 16 kD, apparently a predominant somatic component, appeared to be specific forO. viverrini.
Hymenolepis microstoma: oncospheres invade the intestinal tissue of the definitive host
Authors: Onitake Kazuo , Sasaki Junko , Andreassen Jørn , Ito Akira
Published: June 2009

Although the normal intermediate hosts of Hymenolepis microstoma are insects, oncospheres invade the intestinal tissue of the definitive hosts, mice, within 30 min after oral egg inoculation.
Scanning and transmission electron microscopy of the female reproductive system of Schistosoma margrebowiei Le Roux, 1933
Authors: Awad A. H. H. , Probert A. J.
Published: June 2009

Transmission electron microscopy shows that the uterus of female Schistosoma margrebowiei possesses the same ultrastructure as that of the tegument but lacks spines and sense organs. It does not possess secretory cells and opens at the gonopore which by scanning electron microscopy was seen to be composed of numerous leaf-like protrusions. The morphology of the ovary is comparable with that of other Digenea. Immature and mature ova possess cortically arranged granules and occur within the posterior zone of the ovary. Cilia and lamellae line the luminal surface of the oviduct and ootype, the lamellae running unidirectionally along the duct. Only a single type of secretory cell is seen within Mehlis' gland and this produces dense bodies which are associated with Goldi bodies. Narrow cytoplasmic channels supported by microtubules deliver these secretory bodies to the ootype. The vitelline duct is lined with cilia and lamellae and the vitelline gland contains four types of cells, S1, S2, S3 and S4. Calcareous corpuscles are found within mature S4 cells.
Sites of encystment by the metacercariae ofEchinoparyphium recurvatuminLymnaea peregra
Authors: Adam M. E. , Lewis J. W.
Published: June 2009

Experimental infection ofEchinoparyphium recurvatumvon Linstow (Digenea: Echinostomatidae) cercariae in the snail second intermediate hostLymnaea peregraMüller shows that metacercarial encystment takes place on the lining of the mantle cavity, pericardial cavity and kidney lumen, with the mantle cavity the most preferred site. All three sites are accessible via the body openings. The metacercariae appear to be more susceptible to encapsulation in the visceral mass than in the cavity of the mantle, pericardium and the lumen of the kidney.
Observations on the morphology of adults and larval stages of Oesophagostomum sp. isolated from man in northern Togo and Ghana
Authors: Blotkamp J. , Krepel H. P. , Kumar V. , Baeta S. , Noordende J. M. Van't , Polderman A. M.
Published: June 2009

Infection with Oesophagostomum sp. appears to be extremely common in man in northern Togo and Ghana Adult specimens were recovered from the intestinal lumen by treatment with pyrantel pamoate and the morphological characteristics of oesophagostomes of man could for the first time be compared with information available on the morphology of oesophagostomes of monkeys. The observations and measurements demonstrated that the species involved is Oesophagostomum bifurcum and that the eggs of this species cannot be differentiated from those of Necator americanus. Both infections occur simultaneously in the population involved. The L1 larvae, too, cannot be differentiated from hookworm L1 larvae. The L3 however, are characteristic. Diagnoses of human Oesophagostomum infections is based on the detection of these larvae in coprocultures. In the present paper, the eggs, the L1 and L3 larval stages and the adults, carefully described and photos are given.
The prevalence and intensity of infection with helminth parasites inMus spretusfrom the Setubal Peninsula of Portugal
Authors: Behnke J. M. , Barnard C. , Hurst J. L. , McGregor P. K. , Gilbert F. , Lewis J. W.
Published: June 2009

The results of a 5 year study of helminth parasites ofMus spretus, are reported. Six nematode and 5 cestode species were identified but no helminth showed 100% prevalence inM. spretus, the most commonly encountered nematode and cestode species beingSyphacia obvelata(46·6%) andTaenia taeniaeformis(22·4%). Among the more unusual helminth species identified wasEucoleus bacillatus, a capillariid nematode inhabiting the stomach musculature. This species was identified in 3 of the 5 years of the study. The results are discussed in the broader context of previous studies and the epidemiology of rodent helminth infections in general.
Application of small doses of copper salts (basic and neutral) to Ascaridia galli-infected chicks
Authors: Gabrashanska M. , Galvez-Morros M. M. , Garcia-Martinez O.
Published: June 2009

Male Hisex chicks were used in two experiments to investigate the interaction between Ascaridia galli infection and supplemental copper from basic and neutral salts. This was assessed by means of body weights, mortality, parasite burden and liver copper level. Cu2(OH)3Cl reduced the number of parasites but CuSO4.5H2O and CuCO3.Cu(OH)2.nH2O did not affect the parasite burden.
Karyometrical analysis of Microsomacanthus spasskii and M. spiralibursata
Authors: Petkevičiūtė R. , Regel K.V.
Published: June 2009

Analysis of Giemsa-stained mitotic metaphase plates of Microsomacanthus spasskii and M. spiralibursata (Cestoda: Hymenolepididae) revealed the diploid chromosome numbers for both species to be 2n=6. The karyotypes are remarkably similar in general morphology; they both consist of three pairs of metacentric or meta-submetacentric chromosomes graded in size from 4.3 to 7.0 μm. Slight interspecific differences exist in the position of the centromere of chromosomes of the pair 3. Based on existing chromosome data the possible pathways of the karyotypic evolution within the family Hymenolepididae are discussed.
Lymnaea truncatula, intermediate host of some Plagiorchiidae and Notocotylidae species in León, NW Spain
Authors: Manga-González Y. , González-Lanza C. , Kanev I.
Published: June 2009

To study the distribution of Lymnaea truncatula in the Porma river basin (León, NW Spain) and its helminth fauna, malacological samplings were carried out at 66 points in the basin and the presence of these molluscs was detected in 31. To trace the dynamics of this mollusc population and the prevalence and intensity of its infection by trematodes, malacological samplings were made at fortnightly intervals over two years at five locations, situated in the upper and middle regions of the river Porma basin. To confirm the identity of the larval stages found in the molluscs, second intermediate and/or definitive hosts, depending on the trematode species, were experimentally infected to complete the life cycles. Two different species of Plagiorchiidae and one of Notocotylidae were identified. The infection prevalence of Plagiorchis elegans for the 6291 specimens of L. truncatula examined was 2.8% and infection was observed in snails collected in 7 of the 31 sample localities. This parasite was found in all months of the year, with the highest prevalence observed in July and October. When the corrected frequency values were considered, a slightly positive relationship was observed between the infection prevalence and the latter months. The highest percentages of snails harbouring immature sporocysts were detected in March and June–July, while the highest percentages with sporocysts containing mature cercariae were observed in spring and at the end of summer–autumn, and cercarial shedding in the latter. Of the 6291 L. truncatula examined 0.3% were infected by sporocysts of Opisthioglyphe ranae. The infection was detected in only one locality, in four months of the year, with the highest prevalence in May. Notocotylus neyrai was found in 2.6% of the 6291 mollusc specimens checked and was collected from 12 of the 31 localities. The highest prevalence was observed in October, April and July and the corrected frequency values reveal a positive relationship between the infection prevalence and those three months. The highest percentage of molluscs harbouring rediae of N. neyrai with germinal mass was found in April and September–October. On the other hand, rediae with mature cercariae were present in almost every month, but we only observed cercarial shedding in October and March. The L. truncatula infection prevalence by P. elegans, O. ranae and N. neyrai increased with the size of the molluscs. Double infection was only observed in four snails: one harboured O. ranae and N. neyrai and three F. hepatica and P. elegans.
Prevalence and habitat specificity of steinernematid and heterorhabditid nematodes isolated during soil surveys of the UK and the Netherlands
Authors: Hominick W.M. , Reid A.P. , Briscoe B.R.
Published: June 2009

Entomopathogenic nematodes were isolated from soil samples collected during three separate surveys, two in the United Kingdom and one in the Netherlands. The nematodes were identified by their restriction fragment length polymorphisms on hybridization of Southern blots with a ribosomal DNA repeat unit clone. A total of eight steinernematid species/RFLP types and two heterorhabditids were isolated. The distributions of the majority of these species/RFLP types were significantly different between the three surveys and some of the species displayed a close association with certain habitat types.
Analysis of migration success of Onchocerca lienalis microfilariae in the haemocoel of Simulium vittatum
Authors: Lehmann T. , Cupp M.S. , Cupp E.W.
Published: June 2009

Migration success (i.e. the proportion of worms that reach the thorax) of Onchocerca lienalis microfilariae (mf) in the haemocoel of Simulium vittatum was studied by inoculating mf into the posterior abdomen, and recording their distribution in the blackfly body at predetermined time points. Mf arrive into the thorax by active locomotion rather than by drifting in haemolymph currents. Migration into the thorax was completed by 12 h post inoculation (pi) but was not continuous throughout this period. Migration proceeded in two phases; the first occurred 0–2 h pi and the second at 6–12 h pi. Overall, migration success 12–24 h pi was only 36%, indicating thata substantial number of mf failed to reach the thorax, either because they were eliminated by the fly's defensive response or because they remained in the abdomen. Migration success was density independent Mf that arrive into the thorax within 2 h pi did not differ in their migration potential from mf that remained in the abdomen at this time. In flies where more mf migrated successfully there was lower mf loss, indicating that migration success was linked to mf loss. Moreover, the proportion of mf in the thorax was not correlated with mf loss, suggesting that mf loss affected the number of mf that migrated successfully, rather than the reverse causal relationship.
Population dynamics of freshwater gastropods and epidemiology of their helminth infections with emphasis on larval paramphistomes in northern India
Authors: Mattison R.G. , Dunn T.S. , Hanna R.E.B. , Nizami W.A. , Ali Q.M.
Published: June 2009

Natural populations of the freshwater gastropods Bithynia tentaculata, Gyraulus convexiusculus, Helicorbis coenosus, Indoplanorbis exustus, Lymnaea acuminata, L. luteola and Vivipara bengalensis, were examined from October 1985 to September 1986 at seven transmission sites for paramphistomiasis, fascioliasis and other gastropod-borne infections in Aligarh, northern India. Gastropod diversity and the type and abundance of vegetation were highest at sites containing permanent water bodies. The distributions of H. coenosus and L. acuminata were positively correlated with the type and abundance of vegetation at these sites. Ephemeral water bodies contained B. tentaculata, I. exustus and L. luteola which were resistant to desiccation during the hot season. Aestivation in these gastropods preceded pronounced breeding activity which began with the onset of the monsoon season. Multivariate analysis (by principal components) was used to investigate relationships between each species of gastropod, their site of occurrence and levels of infection with larval helminths. Seasonal variations in numbers and size class structure in these gastropods were found to influence their prevalences of infection with larval helminths. Metacercarial and cysticercoid infections were more prevalent in smaller size classes of B. tentaculata and V. bengalensis, whereas larval paramphistomes were more prevalent in larger size classes of G. convexiusculus, I. exustus and L. luteola. Attempts were made to equate these findings with seasonality in egg shedding by certain species of adult paramphistomes occurring in domestic ruminants.
Experimental studies of the influence of Moniezia expansa infection on oribatid mites
Authors: Schuster R.
Published: June 2009

Eleven artificial infections of oribatid mites of the genusScheloribates with Moniezia expansa eggs were made. The percentage of surviving mites in the infected groups was lower (62 to 82%) than in the uninfected control group (90%). None of oribatids with cysticercoids in their body cavity contained mite eggs. The established prevalence and average cysticercoid number in surviving mites were 50.00 to 95.12% and 1.3 to 2.8 respectively.
Population biology ofPomphorhynchus laevisin brown trout from two lakes in the west of Ireland
Authors: Molloy S. , Holland C. , O'Regan M.
Published: June 2009

Since Ireland is the only country in whichPomphorhynchus laevis(Acanthocephala) uses brown trout(Salmo trutta) as its preferred definitive host, the population biology of the parasite in this host was investigated thus enabling a comparison to be made with data collected onP laevisfrom other hosts, particularly the cyprinids, chub and barbel. Over a period of 12 months, 549 brown trout were caught from two lakes, Lough Feeagh and Bunaveela Lake, in the Burrishoole River system, Co. Mayo, Ireland. The parasite component community was dominated by a single species,P laevis. Fifty eight percent of the trout sample were infected with the acanthocephalan and the mean abundance (± SD) was 3.1 ± 5.1. The relationships between the prevalence and abundance ofP laevisand season and site of host capture and host age and sex were explored. As single factors none of these parameters emerged as significant contributors to changes in parasite abundance although some interaction terms proved to the significant. A random sample of over 700P laevisparasites were subjected to further investigation and their size, position in the intestine and maturity status are described. Parasites attained an average weight of 7 mg and occupied the posteriad positions within the fish intestine(77%). Parasites from this sample of Irish brown trout attained a similar average size to those found in chub and barbel from England. 42.3% of the total parasites examined contained ovarian balls only and 17% contained fully mature acanthors. Therefore only a moderate proportion of female worms contained mature acanthors in these trout whereas the majority of worms recovered from a sample of chub were gravid. Utilizing a logistic regression model, parasite size, season, and site of host capture emerged as particularly significant factors which contribute to whether a parasite contains mature eggs.
Ultrastructure of the male reproductive system in a rumen amphistome Cotylophoron cotylophorum
Authors: Sharma P.N. , Swarnakar G. , Hanna R.E.B.
Published: June 2009

The ultrastructure of various regions of the male reproductive tract and the prostate gland of Cotylophoron cotylophorum (Trematoda: Digenea) is described. The internal lining of the entire male duct system is syncytial in nature, and regional variation is quite evident. The syncytial epithelium of the vas deferens and seminal vesicle is very thin, flat and lamellate and the lumen is packed with spermatozoa. In the pars musculosa (PM) the syncytium is also flat but lamellae are sparsely distributed and anastomosed at places to form loops. The syncytium of the PM is invested by several layers of circular and longitudinal muscle. The pars prostatica (PP) is lined by an uneven but moderately thick syncytial epithelium with nuclei projecting into the lumen. The syncytium bears numerous very long lamellae. The ejaculatory duct epithelium is devoid of lamellae. It is even and moderately thick throughout. The prostate gland cells are uneven in outline and bear long ducts which open into the lumen of the PP. They show an ultrastructural organization suggestive of protein secretion.
Ultrastructural observations on the redial tegument of Paramphistomum epiclitum from the planorbid snail, Indoplanorbis exustus
Authors: Dunn T. S. , Dang P. H. , Mattison G. , Hanna R. E. B. , Nizami W. A.
Published: June 2009

The morphology of the tegument in the redia of Paramphistomum epiclitum (Digenea: Paramphistomidae) resembles that shown by most larval and adult digeneans; an outer surface syncytium is in continuity with the cytoplasm of in-sunken, nucleated cytons. Although tegumental cytons usually contain a single nucleus, some display up to six nuclei. The tegumental syncytium lining the pharynx of P. epiclitum rediae lack underlying cytons. The apical membrane of the tegument is elaborated by folds and microvilli, which presumably facilitate uptake of nutrients and/or exchange of ions involved in osmoregulation. A single type of secretory body, resulting from the fusion of smaller vesicles produced at Golgi complexes in the cytons, occurs throughout the tegument. Uniciliate sensory receptors occur in the surface syncytium particularly around the oral opening.
Embryological development of the cercarial tegument of Paramphistomum epiclitum in the planorbid snail, Indoplanorbis exustus
Authors: Dunn T. S. , Dang P. H. , Hanna R. E. B. , Nizami W. A.
Published: June 2009

Cercariae develop from individual germinal cells occurring freely within the posterior body cavity of rediae. Individual germinal cells give rise to a germinal ball which becomes enveloped by increasing numbers of cytoplasmic extensions originating from specialized parenchyma-like cells, termed nursc cells. Up to eight cytoplasmic layers of nurse cells invest larger germinal balls. These layers may provide mechanical support for developing embryos and/or play a role in the provision of nutrients to them. The cercarial tegument develops from superficially located somatic cells in the germinal ball. Cytoplasmic extensions of presumptive tegumental cells fuse laterally to form a syncytial layer beneath the encapsulating nurse cell layers. As the cercarial tegument differentiates further, the cytoplasm of the nurse cell layers becomes vacuolated and ultimately these layers degenerate. The surface tegumental syncytia of intra-redial cercariae and newly released extra-redial cercariae are nucleated. Separate subtegumental perikarya develop with further differentiation of extra-redial cercariae.
Mitotic chromosomes of Sphaerostomum bramae (Müller, 1776) Szidat, 1944
Authors: Petkevičiūtė R. , Stanevičiūtė G. , Kiselienė V.
Published: June 2009

Karyometrical analysis of conventional Giemsa-stained mitotic chromosomes of parthenitae of Sphaerostomum bramae (Trematoda: Opecoelidae) was carried out. The karyotype displays a typical ‘plagiorchiid’ pattern with 22 chromosomes in a diploid set including a first pair of large metacentric elements. Chromosomes with medially or submedially located centromeres prevail in the karyotype; only chromosomes 7 and 9 are subtelocentric. With the data now available, close karyological affinity was noted between S. bramae, the representative of the family Opecoelidae, and other karyologically studied species of some families in the order Plagiorchiiformes: Troglotrematidae, Plagiorchiidae, Prosthogonimidae, Lecithodendriidae and Telorchiidae.
Adherence of carp leucocytes to adults and cercariae of the blood flukeSanguinicola inermis
Authors: Richards D.T. , Hoole D. , Lewis J.W. , Ewens E. , Arme C.
Published: June 2009

Live adult and cercarial stages ofSanguinicola inermisPlehn, 1905 (Trematoda: Sanguinicolidae) were maintainedin vitroin the presence of carp (Cyprinus carpioL.) leucocytes. Cells and parasites were fixed at intervals from 0.25 to 48 h and examined using light microscopy, SEM and TEM. Within 12 h of exposure, leucocytes were found attached to cercariae although, by 24 h, fewer cells were found attached to postcercarial, juvenile adult stages that had shed their tails. Neutrophils and macrophages were found attached to the damaged tegument of cercariae that had not transformed by 48 h. Few cells were attached to the tegument of adult flukes that were alive when fixed. However, there was extensive tegumental damage and numerous cells were attached to adult flukes that had died before fixation. The results are discussed with reference to parasite survival within the vascular system of the host.
Infectivity and the cercarial tail chamber in Proterometra macrostoma
Authors: Braham G.L. , Riley M.W. , Uglem G.L.
Published: June 2009

The tail chamber's role in the survival and infectivity of Proterometra macrostoma (Digenea: Azygiidae) was investigated. Intact cercariae and cercarial bodies dissected from tails were incubated for 14 h in artificial pond water (APW) and cercarial infectivity was assessed in laboratory infections of the bluegill sunfish, Lepomis macrochirus. Although most cercariae stopped swimming and settled to the bottom after 14 h, survival and infectivity of bodies from intact cercariae did not decrease significantly during this period. All isolated bodies survived in APW, but they were 54% less infective. By contrast, infectivity of isolated bodies did not decrease significantly in an artificial snail saline. The results indicate that maximum infectivity in P. macrostoma is sustained throughout the swimming phase because of the tail chamber which protects the body from the effects of osmotic stress.
Developmental changes in the tegument of four microphallid metacercariae in their second (crustacean) intermediate hosts
Authors: Galaktionov K.V. , Malkova I.I. , Irwin S.W.B. , Saville D.H. , Maguire J.G.
Published: June 2009

The morphology of the tegument of four microphallid metacercariae from the stage of invasive cercariae to their maturation as encysted metacercariae inside their crustacean second intermediate hosts is described. The tegument of the metacercariae developed surface lamellae and projections which, along with coated vesicles in the surface syncytium, indicated that the tegument had an absorptive function. The disappearance of secretory granules from the tegument at the same time as the appearance of the first cyst wall suggested that the tegument had a role in primary cyst production. Following this, the metacercariae continued to grow and seemingly retained their absorptive ability. The tegument was also involved in the transport of material into the perimetacercarial lumen prior to its eventual inclusion in the developing inner cyst layers. It appeared that this material originated in tegumental cells located amongst the parenchymal cells beneath the tegumental syncytial layer. On completion of the secondary cyst layers there was a gradual degeneration of structures associated with absorption and a progressive accumulation of dense discoid granules traceable to underlying tegumental cells. All four microphallid species (Maritrema arenaria,M. subdolum,Levinseniella brachysomaandMicrophallus claviformis) demonstrated the same developmental pattern but the period spent in each stage differed depending on the time spent migrating to encystment sites. The pattern of tegumental development described is thought to be applicable to all microphallid metacercariae and possibly to other metacercariae which undergo growth and development in their second intermediate hosts.
Natural infection of the calanoid crustacean Epischura baicalensis by procercoids of Proteocephalus sp. in Listvenichnyi Bay, Lake Baikal
Authors: Rusinek O.T. , Bakina M.P. , Nikolskii A.V.
Published: June 2009

Natural infection of the plankton Epischura baicalensis Sars (Calanoida: Temoridae) by procercoids of the genus Proteocephalus in Lake Baikal is analysed in detail. Over one year Epischura was infected by procercoids of proteocephalids at a prevalence of 0.13% (in Listvenichnyi Bay, South Baikal). Male E. baicalensis were infected more (0.39%). The number of procercoids of genus Proteocephalus was 2.7 specimens/m3. The largest number of procercoids was found in females (1.26), the least in the third copepodid stage (0.03 specimens/m3). Because of the close ecological contacts between E. baicalensis and Coregonus autumnalis migratorius it is probable that E. baicalensis is infected by P. exiguus, the species usually found in C. a. migratorius (Zaika, 1965). The parasite lives for about 8 months in the winter-spring Epischura generation and about 10 months in the summer generation.
Characterization of Spanish Trichinella isolates by random amplified polymorphic DNA (RAPD)
Authors: Rodríguez E. , Nieto J. , Castillo J.A. , Gárate T.
Published: June 2009

The random amplified polymorphic DNA (RAPD) assay was used to find molecular markers able to distinguish Trichinella spiralis from T. britovi, the two recognized Spanish Trichinella species. Fourteen Spanish Trichinella isolates, as well as reference Trichinella isolates representing the five species T. spiralis (T1), T. nativa (T2), T. britovi (T3), T. pseudospiralis (T4) and T. nelsoni (T7) and the three other taxa Trichinella T5, Trichinella T6 and Trichinella T8 of the genus, were characterized by RAPD using both purified and crude DNAs from infective muscle larvae (ML) and seven arbitrary primers. Three primers yielded diagnostic RAPD markers for the Spanish T. spiralis and T. britovi isolates as well as for the Trichinella reference isolates analysed, and in the case of crude DNAs the results were obtained in few hours. In addition, the species-specificity of the diagnostic RAPD markers from Spanish Trichinella isolates was studied by cross-hybridization assays. These assays confirmed that the selected diagnostic DNA fragments were not species-specific, but showed potential differences in the copy number among the examined Trichinella genetic clusters.
Morphological comparison and identification of metacercariae in the ‘pygmaeus’ group of microphallids, parasites of seabirds in western palaearctic regions
Authors: Saville D.H. , Galaktionov K.V. , Irwin S.W.B. , Malkova I.I.
Published: June 2009

This study compares the metacercariae of a ‘pygmaeus’ microphallid discovered inLittorina saxatilisfrom the coast of Northern Ireland with the metacercariae ofMicrophallus piriformesandM. pygmaeusfrom the same species of gastropod mollusc from Arctic Russia. Light and scanning electron microscopy were used to provide morphometric and surface details for descriptions of the organisms concerned. Comparison and statistical analysis of the results established that the species from Northern Ireland wasM. piriformesand notM. pygmaeusas had previously been assumed. It dearly indicates the need for critical assessment of the accuracy of literature dealing with the occurrence of ‘M. pygmaeus’ in both intermediate and final hosts.
Infectivity of a Cambodian isolate of Schistosoma mekongi to Neotricula aperta from northeast Thailand
Authors: Attwood S.W. , Kitikoon V. , Southgate V.R.
Published: June 2009

All three strains of Neotricula aperta (Gastropoda: Pomatiopsidae) sampled from populations in northeast Thailand were found to be compatible with a Schistosoma mekongi isolate from Kratié District, eastern Cambodia. The infection rates were: 3.0%, α-strain; 6.0%, β-strain; and 20.5%, γ-strain. The greater infectivity to the γ-strain, over both the α- and β-strains, was statistically significant. Comparisons of infectivity patterns for the Kratié isolate, with those described in earlier studies using S. mekongi isolates from southern Laos, revealed differences among the strains. The γ-strain of N. aperta is responsible for endemic transmission of human schistosomiasis in southern Laos and at Kratié. Consequently, the findings of this study are of use in the prediction of changes in the distribution of Mekong schistosomiasis, particularly its introduction to northeast Thailand from the neighbouring countries, Cambodia and Laos.
Glutathione-s-transferase is an important antigen in the eel nematodeAnguillicola crassus
Authors: Nielsen M.E. , Buchmann K.
Published: June 2009

Different organs and secretions/excretions of the swimbladder parasite,Anguillicola crassus(Nematoda), were tested for the presence of antigens to the humoral immune response previously detected in the European eel,Anguilla anguilla. Proteins from different fractions ofAnguillicola crassuswere separated using SDS–PAGE (sodium-dodecyl-sulphate polyacrylamide-gel electrophoresis) under reducing conditions and electroblotted onto nitrocellulose membranes. Infected eels showed a specific antibody response to a 43 kDa antigen in the cuticle and towards two gonad antigens around 34 and 43 kDa. In protein released from the worms, two secretory/excretory antigens of approximately 28 kDa were found. The secretion/excretion rate of protein from the parasite to the surroundings was determined. Subsequently, an ELISA system was established applying these antigens as the first layer of coating. Furthermore, antigens fromAnguillicola crassuswere examined for the presence of glutathione-s-transferase (GST) using a specific antibody against GST. The antigens were found to be subunits of GST.
Filarial DNA and its interaction with polyamines and antifilarial drugs
Authors: Pandya U. , Saxena J.K. , Shukla O.P.
Published: June 2009

The interaction of DNA from filarial parasite Setaria cervi with polyamines was monitored by melting temperature (Tm) profile, condensation and B to Z DNA transition and compared with DNA of Escherichia coli, Micrococcus luteus and calf thymus having different GC content. Polyamines, viz. spermine and spermidine, stabilized the secondary structure of all DNAs as indicated by increase in Tm value. UV absorption studies indicated B to Z DNA transition in the presence of polyamines. The amount of polyamines required for B to Z transition was dependent upon base composition of DNA and charge of the polyamine. Filarial DNA (AT rich) required six times higher concentration of spermine as compared to GC rich DNA for B to Z DNA transition. Spermidine was not effective in causing transition of S. cervi DNA even at Spd:DNA-P ratio of 20. The antifilarial compound suramin significantly decreased melting temperature of filarial DNA as compared to GC rich DNAs of other parasites. Suramin adversely affected condensation and B to Z DNA transition of various DNAs but prior addition of polyamines protected the DNAs from the destabilizing effect of suramin.
Proteinases secreted byFasciola hepatica: time course of the inhibitory effect of serum from experimentally infected rabbits demonstrated by gelatin-substrate polyacrylamide gel electrophoresis
Authors: Piacenza L. , Acosta D. , Dowd A. , McGonicle S. , Dalton J. , Carmona C.
Published: June 2009

Fasciola hepaticasecretes proteolytic enzymes to aid it to penetrate and migrate through the host tissues. Two of these proteinases have been purified and shown to be cathepsin L-like, and are termed, CL1 (27.5 kD) and CL2 (29 kD). The immunogenicity of these proteinases was investigated over the course of an experimental infection and following drug treatment. Four groups of rabbits were studied: group 1: orally infected with 50 metacercariae; group 2: infected and treated 8 weeks after infection; group 3: infected, treated at week 8 and reinfected at week 13 and group 4: non-infected control group. Sera were collected weekly from each group until week 20 postinfection. CL1 and CL2 were incubated with the different sera and then analysed by gelatin substrate polyacrylamide gel electrophoresis (GS-PAGE). Analysis of groups 1, 2 and 3 showed that CL1 and CL2 neutralizing antibodies appear at week 5 post-infection. In group 1, these remained throughout the 20 weeks of infection. In group 2, neutralizing antibodies disappeared at week 13, that is, 5 weeks after anti-Fasciolatreatment. In group 3, CL1 and CL2 neutralizing antibodies disappeared at week 13 but reappeared by week 15, that is 2 weeks after reinfection. Pooled sera from group 4, showed no inhibitory capacity. ELISA results using CL1 and CL2 as antigen, correlate very well with the inhibitiory time course observed by GS-PAGE. These results suggest that purified cathepsin Ls are antigenic molecules recognized early in the infective process and capable of inducing a specific humoral response, strong enough to neutralize, at least partially, their enzymatic activity.
Some histochemical characteristics of the mucous microenvironment in four salmonids with different susceptibilities to gyrodactylid infections
Authors: Buchmann K.
Published: June 2009

Skin mucous cells and mucus from four salmonids (rainbow trout, brown trout, Conon salmon, Iijoki salmon) with different susceptibilities to infection withGyrodactylus derjaviniandG. salariswere partly characterized by cytochemistry, immunoblotting and immunocytochemistry. Mucous cell densities in various fin types were partly correlated with resistance to infection withG. derjavinibut not withG. salaris. Lectin binding assays indicated slight differences in carbohydrate composition of mucus from the four salmonids but serum antigens specific for salmonids were found in mucus from all of them. Antisera against salmon immunoglobulin and rainbow trout complement factor C3 reacted with mucus from all of the salmonids but not with mucus from phylogenetically unrelated fish. Antisera raised against ACTH reacted with mucus components from rainbow trout, brown trout and Conon salmon but not with mucus from Iijoki salmon. These findings are discussed in relation to the host specificity of ectoparasites and susceptibility to infection.
Characterization ofFasciola hepaticaredial generations by morphometry and chaetotaxy under experimental conditions
Authors: Augot D. , Rondelaud D. , Dreyfuss G. , Cabaret J. , Bayssade-Dufour C. , Albaret J.L.
Published: June 2009

Morphometric and chaetotactic studies were carried out on the body and cephalic regions of the rediae ofFasciola hepatica(Trematoda: Fasciolidae) in order to precisely identify the different redial generations of this trematode inLymnaea truncatulaunder experimental infection. At day 49 post-exposure at 20°C, the length of the redia was significantly higher in the first group of the first generation (R1a) compared with successive generations, R1b, R2a and R2b/R3a. The width of the body was similar in the R1a, R1b, and R2a rediae, but was significantly lower in the R2b/R3a groups. The intrapharyngeal cavity of R1a rediae was significantly wider compared with the R1b, R2a, and R2b/R3a groups, whereas the pharyngeal wall was significantly thicker in the R2b/R3a rediae compared with the R1b and R2a groups. Four other measurements, namely the maximum length and width of the pharynx, diameter of the mouth, and width of intestine, also showed significant variations in relation to pharyngeal morphology and age of infection. Discriminant analysis based on these measurements demonstrated that 98% of the rediae were readily categorized into the four groups identified. The number of perioral sensillae ranged from 126 to 160 but a significant difference was only noted between the mean values of the first generation and those of the group R2b/R3a. From these parameters, the maximum width of the pharyngeal lumen was found to be the best characteristic in the identification of the redial generations.
The structuring process of the macroparasite community of an experimental population of Cichlasoma urophthalmus through time
Authors: Vidal-Martinez V.M. , Kennedy C.R. , Aguirre-Macedo M.L.
Published: June 2009

The structuring process of the macroparasite community of caged Cichlasoma urophthalmus was studied over time using sentinel fish. Three thousand uninfected cichlids were stocked in floating cages introduced into a quarry in which a wild population of the same species was present. Caged and wild cichlids were sampled monthly over 6 and 7 months, respectively. Seventeen macroparasite species were found in the wild C. urophthalmus population, ten of which were detected in the caged population after 6 months. Early infections were by those species that were more frequent and abundant in the wild population, while helminths with a low prevalence and abundance in the wild appeared later in the caged fish population. The results suggested that the structuring process of the macroparasite community of caged C. urophthalmus followed a predictable pattern, in which those species that were most frequent and abundant in the wild were the first to establish in sentinel fish.
Helminth fauna of the Iberian lynx, Lynx pardinus
Authors: Torres J. , García-Perea R. , Gisbert J. , Feliu C.
Published: June 2009

Specimens of 12 helminth species were collected from carcasses of eight Lynx pardinus (Temminck, 1827), a carnivore endemic to the Iberian Peninsula. These species included: Brachylaima sp. (12.5%) (Trematoda); Taenia pisiformis (12.5%), T. polyacantha (25%), T. taeniaeformis (25%) and Mesocestoides litteratus (37.5%) (Cestoda); Eucoleus aerophilus (12.5%), Ancylostoma tubaeforme (12.5%), Toxocara cati (37.5%), Toxascaris leonina (62.5%), Vigisospirura potekhina potekhina (12.5%), Mastophorus muris (12.5%) and Physaloptera praeputialis (12.5%) (Nematoda). The helminth fauna in Iberian lynx is compared with that of L. canadensis and L. rufus in America, and for L. lynx in Eurasia. The potential relationships between the parasitological data and some geographical, historical and dietary factors are discussed.
Ecology of Proteocephalus torulosus in the blue bream (Abramis ballerus) from the Oder River on the borders of Germany and Poland
Authors: Pietrock M. , Krüger R. , Meinelt T.
Published: June 2009

During studies on the ecology of fish helminths, the tapeworm Proteocephalus torulosus (Batsch, 1786) was frequently found in the intestine of the blue bream (Abramis ballerus) from the Oder River (Germany/Poland). In total, 633 fish, ranging between two and 16 years old, were sampled at monthly intervals over a two year period during 1993–1995. Statistically significant differences in the seasonal occurrence of the parasite in its fish host were observed. In 1993, the prevalence remained at a high level, ranging between 61.9 and 100%. During the summer of 1994, this value decreased to 5.5% and remained low for the rest of the year. The pattern of mean intensity of infection was similar to that of the prevalence. In 1993, the mean intensity varied between 8.4 and 31.8 worms per infected fish, with a continual loss of worms being observed in the summer of 1994. Changes in the amount of suspended particulate matter in water have been identified as the main cause of these observed differences in the course of infection of blue bream.
The ultrastructure of the cuticle and sheath of infective juveniles of entomopathogenic steinernematid nematodes
Authors: Patel M.N. , Wright D.J.
Published: June 2009

The ultrastructure of the cuticle of infective juveniles (IJs) ofSteinernema carpocapsae(newly emerged and 80-day-old) and newly emerged IJs of S.riobravis, S. feltiaeandS. glaseriwas examined using transmission electron microscopy. The thickness of four distinctive layers of the cuticle was measured: epicuticle, cortical and median layer, striated layer and fibrous mat. The thickness of the cuticle was correlated with the size of the IJ. In the case of newly emerged IJs, the smallest species,S. carpocapsae, had a cuticle thickness ofc.270 nm compared withc.460 nm forS. glaseri, the largest of the four species. The overall thickness of the cuticle or the thickness of the cuticle layers was not correlated with the ability of the IJs of the four species to survive desiccationper se.The major difference between newly emerged IJs of the four species was thatS. carpocapsaehad a proportionately thicker striated layer compared with the other three species. The significance of this is not known but it may be an adaptation involving the nictation behaviour of this species. A substantial change was observed in the cuticle of aged (80-day-old) IJs ofS. carpocapsae, whereby the thickness of the cortical and median layer increased by more than 100% and the overall thickness of the cuticle increased by about 50%. Two possible explanations for this increase are: (i) new material was synthesized; or (ii) the fluid content of this layer increased due to an increase in the permeability of the outer layers of the cuticle. The ultrastructure of the sheaths ofS. feltiaeandS. glaseriwas also examined and, apart fromS. glaserihaving a thicker sheath, the structure of the sheath in both species was similar, with the epicuticle and striated layer still visible.
Mitochondrial DNA diversity in nematodes
Authors: Blouin M.S.
Published: June 2009

The relatively small literature on mitochondrial DNA (mtDNA) diversity in nematode species is summarized here. Nematodes show a wide range of overall genetic diversities and population genetic structures. Species-wide levels of diversity correlate strongly with the breeding system and other life cycle features that control effective population size. Obligate outcrossers that parasitize mobile vertebrate hosts are the most diverse, species having hermaphroditic stages are less so, and species having asexual reproductive stages appear even less diverse. Nevertheless, these conclusions are preliminary because there exist so few data on DNA diversity in nematodes. What is needed are more comparative studies using similar sampling designs and the same DNA markers, including nuclear loci and further work with mtDNA