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ABSTRACT: On the Atlantic Moroccan coast, two species of pleuronectiform fish coexist, wedge sole (Citharus linguatula) a temperate species, and spotted flounder (Dicohgoglossa cuneata) a tropical one. These two species are the definitive host for Bothriocephalus andresi and Acanthocephaloïdes propinquus, respectively. A negative binomial fits the dispersion of B. andresi in the population of C. linguatula. The fish become parasitized between their first and third year, while still immature, with the highest abundances in the third year. After the fish become ichthyopagous, the level of infection drops drastically. We postulate that copepods are the sole source of infection. The presence of B. andresi in both Atlantic and Mediterranean populations of C. linguatula shows that the parasite follows the host during its migration along the Mediterranean coasts.The prevalence of A. propinquus remains above 50% as a consequence of the large numbers of amphipods included in the diet of D. cuneata, regardless of the age of the fish or the season. The amphipods, Phtisica marina and Pariambus typicus are an important food and represent potential intermediate hosts for A. propinquus. The population dynamics of A. propinquus on the Atlantic Moroccan coasts are similar to those observed in parasite populations of Gobius niger in the Gulf of Lion (French Mediterranean). The observation of B. andresi and A. propinquus in both Moroccan Atlantic and Mediterranean fishes highlights the problem of the evolution of these parasite populations during the colonization of the Mediterranean by the hosts.
Journal of Fish Biology 04/2005; 44(6):1005 - 1021. · 1.68 Impact Factor
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ABSTRACT: The hypothesis that asexual multiplication inside the intermediate host and adult life-history traits within the final host are independent is tested among Cestoda. Using phylogenetic relationships among the Cestoda species, we can show that asexual multiplication appears to have been lost and recovered several times throughout Taeniidae evolution; this allows a comparison of the adult life-history traits of species with and without asexual multiplication at the larval stage. The adult trait considered is the size of the parasite, since numerous life-history traits, such as fecundity and longevity, are correlated with size. If adult traits are independent of whether the larval stage reproduced asexually or not, we expect no difference in the adult size of the proliferative (i.e. with asexual multiplication) and non-proliferative species. The results are inconsistent with this hypothesis. In contrast, species with asexual multiplication in the intermediate host seem to have smaller adult size, reflecting a trade-off. We propose that ecological factors involving intraspecific and interspecific competition in the final host might be responsible for this trade-off. The role of these parameters in the evolution of life-history traits and more precisely in the acquisition of asexual multiplication is investigated with comparative analysis and discussed in the context of host-parasite interactions.
Parasitology Research 02/2003; 89(2):81-8. · 2.15 Impact Factor
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ABSTRACT: The two monogenean species Metamicrocotyla cephalus and Microcotyle mugilis have specific microhabitats on the gills of Mugil cephalus on which they may or may not coexist. M. cephalus is found in sector 1 of the posterior hemibranch of arch I. M. mugilis is found on the filaments of sector 5 of the posterior hemibranch of arch I. The coexistence of these two monogenean species on the same fish does not induce a change in their respective distribution, except for a marked preference of M. cephalus for the left side and of M. mugilis for the right. This 15-month-long study shows that when the two species of monogeneans coexist the infection prevalence and intensity are higher than in cases of monospecific infection. The specific character of the microhabitat, the apparent absence of interspecific competition, and the existence of positive species interactions are discussed.
Parasitology Research 02/1998; 84(4):315-20. · 2.15 Impact Factor
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ABSTRACT: E. multilocularis protoscoleces were co-cultured with hepatic cells in the presence of IAR 20 or BALB/c 3T3 cells. Hepatocyte activity was determined by assaying transferrin and albumin secretion in culture media. The level of these 2 plasma proteins is higher in hepatic/BALB/c 3T3 co-culture medium. In the presence of parasites, the transferrin level is unchanged while the production of albumin is stimulated during the first 48 h. Our results suggest that the albumin production could be attributed to a complex cellular cooperation between hepatocytes and activated Kupffer cells as previously observed in the acute inflammatory reaction.
International Journal for Parasitology 02/1995; 25(1):127-30. · 3.39 Impact Factor
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ABSTRACT: Echinococcus multilocularis protoscolices collected from experimentally infected jirds were incubated for 2 weeks in rat hepatic cell cultures cocultivated with or without feeder cells (BALB/c 3T3 and IAR 20). Scanning and transmission electron microscopy studies were performed during the course of the culture period. Kupffer cells (Kc) were seen adhering to the anterior and posterior ends of the protoscolices. Some protoscolices were fixed to the cell monolayer by a cluster of Kc adhering to the posterior end of the parasite. These cells were phagocytosing the glycocalyx and the electron-dense distal end of the microthrix of the protoscolex tegument. An alteration in the superficial tegumental cytoplasm with extensive mitochondrial damage was also noted. The properties expressed by Kc against protoscolices in vitro might also be relevant for proliferation of metacestodes in vivo.
Parasitology Research 02/1994; 80(5):381-7. · 2.15 Impact Factor
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ABSTRACT: This study describes the synthesis of propargylic alcohols derived from isatin and their biochemical and morphological effects on Echinococcus multilocularis metacestodes in Meriones unguiculatus. Propargylic alcohols decreased the alkaline phosphatase and the lactate dehydrogenase activities of the metacestode selectively. The most effective compound, 1b, decreased the lactate dehydrogenase enzymatic activity, and the glucose concentration in the parasite increased, whereas the glycogen content was partially decreased. Furthermore, the ultrastructure study revealed several damages. The host-parasite relationships are very important in the intrahepatic cestodes as shown by the biochemical side effects observed in the host's liver during the treatment. An in vitro enzymatic study was performed with alcohols 1b and 1c.
Journal of Pharmaceutical Sciences 07/1993; 82(6):605-9. · 3.06 Impact Factor
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ABSTRACT: Ultrastructural investigations (SEM, TEM) combined with lectin-binding analysis, have revealed concurrent modifications in tegumentary structure and surface glycoconjugates during the establishment and differentiation of Echinococcus multilocularis metacestodes in jirds. The laminated layer, which is amorphous and rich in polysaccharides when initially secreted by the young cyst, takes on a different appearance and has a different glycoconjugate composition according to whether the cyst becomes fertile or sterile. The laminated layer of fertile cysts transforms into a microfibrillar matrix, the protein content of which may increase while sugar content decreases during protoscolex differentiation. Independently of this structure, brood capsules, from which arise protoscoleces, are formed by invagination of the cyst tegument. The intense secretion of glycoconjugates from the brood capsule wall during invagination may serve to interact with host factors passing through the laminated layer. The combined use of ultrastructural study and lectin labelling has allowed the demonstration of an ultrastructural and biochemical gradient of differentiation of the protoscolex. Seven stages of differentiation have been described. The possibility that the excreted-secreted tegumentary glycoconjugates, revealed by lectin labelling during protoscolex differentiation, might be the gradual biochemical expression of one or several stimuli implicated in the phenomenon of protoscolex maturation, is discussed.
Parasitology 03/1992; 104 Pt 1:129-41. · 2.96 Impact Factor
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ABSTRACT: Micropore chambers containing unevaginated protoscoleces of E. multilocularis were implanted into the peritoneal cavity of AKR mice. Transformation from protoscoleces to fertile multivesicular cysts was obtained after 210 days. Ultrastructural observations of these morphological transformations indicate that a phase of histogenesis follows a phase of dedifferentiation. This morphogenetic process raises the question of the origin of new cell populations. The results reveal the potential role of protoscoleces in secondary echinococcosis and the value of this experimental model for further studies on the larval development.
International Journal for Parasitology 07/1991; 21(3):383-6. · 3.39 Impact Factor
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ABSTRACT: Relationships between sympatric populations of four species of Cestoda belonging to the genus Bothriocephalus (B. barbarus. B. gregarius, B. funiculus and B. scorpii) and populations of their respective hosts Scophthalmus rhombus, Pserra maxima, Ciliata mustela and Myoxocephalus scorpius were investigated. The parasites were overdispersed within their host populations. The mean intensities of B. burbarus were 1.59 (s.d.=0.83) in the Mediterranean (Gulf of Lions) and 1.25 (s.d.=0.53) in the Atlantic (coasts of Brittany). The mean intensities of B. gregarius were 62.3 (s.d.=49.7) in the Mediterranean and 14.06 (s.d.=18.48) in the Atlantic, compared to 1.78 (s.d.=0.3) for B. funiculus and 21.6 (s.d.=17.3) for B. scorpii.The distribution of prevalence of B. gregarius corresponded to a lognormal distribution while those of B. barbatus and B. fwticulus corresponded to negative binomials. No differences in infection could be related to host sex. The parasitization of B. gregariusdepended on host size. In brill, infection by E. barbatus was independent of host size and remained stable after the fish reached 180mm in length. Parasitization of turbot by E. gregarius was lower in young fish (≤110–150 mm) and increased with the host size. Compared to the Atlantic populations of B. gregarius and B. barbatus, the Mediterranean populations were more frequently and intensively infected. The differences in the population dynamics of B. gregarius and B. barbarus would appear to depend on whether or not the life cycle involves a paratenic host.
Journal of Fish Biology 07/1990; 37(2):327 - 342. · 1.68 Impact Factor
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ABSTRACT: Whole specimens and histological and semi-thin sections of Bothriocephalus gregarius adults were exposed to lectins to identify carbohydrates present in the tegument and parenchyma. The sugars N-acetyl glucosamine, N-acetyl galactosamine, galactose, glucose (or mannose) and fucose were detected in the cestode using eight lectins: WGA (Wheat germ agglutinin), HPA (Helix pomatia agglutinin), SBA (Soy bean agglutinin), PHA (Phaseolus vulgaris agglutinin), RCA60 and RCA120 (Ricinus communis toxin and agglutinin), ConA (Concanavalin agglutinin) and UEA-I (Ulex europaeus agglutinin). Combined use of these methodological approaches (whole specimens, paraffin and semi-thin sections) revealed the presence of a gradient in the distribution of most of the sugars over the tegument, with the highest concentrations on the strobila (as shown by most of the lectins). Other sugars were specific for the scolex or strobila (as shown by UEA-I or HPA, respectively). The ultrastructural study showed that the distribution of glycoconjugates was associated with the presence of specific tegumental coats. The significance of this selective distribution and its relevance to cestode physiology and host-parasite relationships are discussed.
International Journal for Parasitology 06/1990; 20(3):285-97. · 3.39 Impact Factor
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ABSTRACT: In the Mediterranean, the parasitic copepod Lepeophtheirus thompsoni Baird, 1850 specifically infests turbot (Psetta maxima L., 1758), whereas L. europaensis Zeddam, Berrebi, Renaud, Raibaut, and Gabrion, 1988 infests brill (Scophthalmus rhombus L., 1758) and flounder (Platichthys flesus L., 1758). Experimental infestation of turbot by copepods from each of the three fish species showed an absence of any physiological incompatibility preventing natural development of the two parasite species, at least on one host species, i.e., the turbot. Moreover, interspecific hybrids were obtained experimentally, which implies that 1) there is no strict genetic barrier between the two species and 2) the natural prezygotic isolation results from a choice of the most favorable habitat. We discuss the origin and possible consequences of the presence, in the Mediterranean, of L. europaensis on brill and flounder, two hosts separated by their taxonomic status and ecobiology.
Journal of Experimental Zoology 06/1990; 254(2):207-14.
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ABSTRACT: The fine structure and differentiation of the embryonic envelopes before and after hatching in two bothriocephalid species of teleostean fish are described. Scanning electron microscopic observation of the egg surface confirmed the specific ornamentation of the capsule. Its thickness and topographic morphology reflect the physiocochemical characteristics of the environment. Beneath the eggshell, two syncytial layers were observed around the oncosphere. The outer envelope, visible during the preoncospheral phase, degenerated before the liberation of the coracidium. Glycoconjugate labelling confirmed the nutritive character of this layer. After hatching, the inner envelope was the only layer covering the oncosphere. The apical plasma membrane of the coracidial sheath bore cilia and numerous clublike microvilli. Beneath the cortical zone, the syncytial cytoplasm was vacuolated, resembling a honeycomb; the electron-dense zone, described from other pseudophyllideans, was not present. The basal membrane of the inner envelope, uniformly electron-dense, was assimilated by the oncospheral membrane. Comparison of the composition of the embryonic envelopes of pseudophyllideans with those of other tapeworm orders and trematodes revealed ontogenetic, structural and functional similarities between the embryotrophic layers. The physiological and ecological significance of the structure of the free-swimming coracidium is discussed. In this respect, the inner envelope around the oncosphere appears to be responsible for the inability of the larva to detect and invade the intermediate host.
Parasitology Research 02/1990; 76(3):251-62. · 2.15 Impact Factor
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ABSTRACT: A study on the biochemical and ultrastructural effects of isatin on Echinococcus multilocularis metacestodes in Meriones unguiculatus is reported. In the metacestode, after an 18 day treatment period, the alkaline phosphatase and lactate dehydrogenase activities decreased and the acid phosphatase activity increased. Glucose and glycogen stores declined significantly. Examinations of the ultrastructure revealed an increase of lysosomes and phagocytic reactions. The protoscolesces were damaged and an abnormal striated process appeared. The tegumental cytoplasmic syncytium remained unaltered. These observations suggest that isatin derivatives may have a role in the chemotherapy of infections caused by Echinococcus spp.
Journal of Antimicrobial Chemotherapy 03/1989; 23(2):237-45. · 5.07 Impact Factor
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ABSTRACT: The effect of isatin on the E. granulosus cyst was studied. NMRI mice, which were infected with E. granulosus of sheep origin, were treated daily with isatin at a dose of 50 mg kg-1 for 18 days. Ultrastructural damage was observed in the treated cysts, including accumulation of lamellar stacks, electron-dense granules, autophagosomes and lipid vesicles. Moreover, a biochemical study showed an inhibition of alkaline phosphatase activity, with a decrease in carbohydrate storage and an increase in acid phosphatase activity. In spite of the short duration of the treatment, the results obtained allowed us to conclude that isatin acts on E. granulosus cysts. This activity appears as a process of degeneration linked to the alkaline phosphatase inhibitory effect of isatin.
Veterinary Parasitology 12/1988; 30(1):31-44. · 2.58 Impact Factor
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ABSTRACT: Using biochemical genetic methods, we have distinguished 2 sibling species in the complex Bothrimonus nylandicus (Schneider, 1902), which infest 2 congeneric species of sole (Solea lascaris and Solea impar) on European coasts (Atlantic and Mediterranean). Neither of the parasite species is specific for either of the sole species, but one of them is present all year round, whereas the other is absent in the autumn and winter and only appears in the spring, subsequently disappearing at the end of the summer. Only S. impar lives in the Mediterranean, and is equally infested by both cestodes, whereas both species occur in the Atlantic and each of them is preferentially infested by 1 species of cestode. The shortness of the adult stage of the parasite in the definitive host and the presence of 2 life-cycles associated with competition between the 2 hosts in the Atlantic could be responsible for the biological differences observed and for maintaining the sibling species in sympatry.
Parasitology 09/1988; 97 ( Pt 1):139-47. · 2.96 Impact Factor
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International Journal for Parasitology 08/1988; 18(5):611-21. · 3.39 Impact Factor
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ABSTRACT: In the eastern Mediterranean, the copepod Lepeophtheirus thompsoni Baird, 1850, has been reported to infest turbot, brill and flounder. By combining several methods, including enzyme electrophoresis, we show that this species is found only in turbot. By contrast, brill and flounder are infested by a species of Lepeophtheirus that corresponds to no other species reported in the literature. We propose that the species be designated as L. europaensis and we describe the characteristics of the gravid female. This study was extended to the Atlantic populations of flatfishes and includes an investigation of L. pectoralis (Muller, 1776), which infects flounder in the North Sea; we also confirmed the presence of L. thompsoni (Baird, 1850) over the whole geographic range of turbot. Lastly, we discuss the specificity and distribution of these species along the European coasts.
Parasitology 03/1988; 96 ( Pt 1):129-44. · 2.96 Impact Factor
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Parasitology Research 02/1988; 74(4):399-402. · 2.15 Impact Factor
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ABSTRACT: Carbohydrate moieties have been detected with nine fluorescent lectins in Echinococcus multilocularis cysts, developed in liver and lung of infested jirds. Tegument and glycocalyx, and two types of medullary cells were found to selectively and strongly bind lectins which are specifically adsorbed by N acetyl glucosamine, N acetyl galactosamine, galactose or mannose. The significance of these features in the host-parasite interaction are discussed.
Comptes rendus des séances de la Société de biologie et de ses filiales 02/1988; 182(5):501-8.
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International Journal for Parasitology 03/1987; 17(3):773-80. · 3.39 Impact Factor
