Caprine Paramphistomum daubneyi (Trematoda) infection in Europe.
Explore the source record for details and available documents.
Animal Husbandry↗
Biomedical subjects
J Cabaret
Publications and source records attributed to J Cabaret.
Allopatric combination of Fasciola hepatica and Lymnaea truncatula is more efficient than sympatric ones.
Parasites are capable of rapid evolutionary changes relative to their hosts, due to short life cycle, short generation time, and high fecundity. The direction of the evolution of parasite virulence can be studied in cross-transfer experiments, combining hosts and parasites from different localities, and comparing the outcome of established (sympatric and potentially locally adapted) and novel (allopatric) combinations of hosts and parasites. We aimed to compare the compatibility with snails hosts, the infectivity of metacercariae in rabbits and rats, and the fitness among different combinations (French-FF and Spanish-SS sympatries and allopatry-FS). The first isolate of Fasciola hepatica and its corresponding intermediate host, Lymnaea truncatula originated from Lugo's northwestern Spain. The second isolate of parasite and snail was collected in the Limoges area in central France. The Spanish snails were more susceptible to their sympatric trematode than the French snails. The Spanish flukes were more infective to intermediate hosts (snails) than the French flukes, but subsequent definitive hosts (rats or rabbits) infections remained similar. The estimated fitness was low in sympatric infections and highly similar (from 4.7 to 5.3). The fitness similarity corresponds, however, to different variations in life-history traits that could represent different strategies among the host-parasite local combinations. The infection rate in snails, metacercarial productivity, metacercarial infectivity, and the estimated fitness were better for allopatric combination (FS). The susceptibility data showed a higher efficiency of flukes in the allopatric snail population than in their local snail population. However, our results were obtained after one generation and from a single isolate and it remains to be determined if all allopatric fluke-snail isolates may present a better fitness. Nevertheless our results indicate that introduction of liver fluke-infected cattle should be monitored carefully, as it could result in the introduction of more efficient parasites.
Animals↗
Rapid detection and quantification of Cryptosporidium baileyi oocysts in feces and organs of chickens using a microscopic slide flotation method.
A simple semiquantitative microscopic slide flotation (MSF) method using modified Sheather's sugar solution (MSSS) is presented for the rapid detection and quantification of Cryptosporidium baileyi oocysts in the feces and mucosal and/or organ scrapings of chickens. Oocyst shedding was evaluated by examination of the surface of coverslips, and the average quantitative score (0-5) recorded for 10 microscopic fields (magnification x250) is reported. The equivalence between these scores and the actual number of oocysts counted per gram of feces was assessed (rs = 0.89; P < 0.001). The applicability of this method was tested by comparison of the kinetics of oocyst shedding in feces of inoculated chickens with those reported by other authors working under similar conditions. In organs the MSF method was compared to histology. Fewer false-negative results were obtained using MSF versus the histology method. The MSF method was particularly more efficient in tracheae with low levels of infection and in the lungs, regardless of the level of infection. The MSF method was also very efficient in detecting oocysts in air sacs from chickens with aerosacculitis. It provides a specific and sufficiently sensitive, simple, rapid, reliable, and low-cost means of diagnosing C. baileyi in the feces and organs of chickens. This method can be used in the routine diagnosis of cryptosporidia in chickens, and it could be extended to other avian species and used in epidemiology studies to evaluate the prevalence of cryptosporidiosis in fowl.
Animals↗
Prevalence of Paramphistomum daubneyi infection in cattle in central France.
Investigations at the slaughterhouse of Limoges (Central France) were performed in 1994-1996 to determine the prevalence of Paramphistomum daubneyi infection in cattle. In 1994/1995, higher prevalences of P. daubneyi were recorded in May, October, and January. In 1996, smaller variations were recorded, and prevalence in April and May was higher. The prevalence of P. daubneyi in summer was lower. Breed and age of cattle were not significantly associated to P. daubneyi infection, but females were significantly more infected than males. P daubneyi infection was related to that of Fasciola hepatica, but not to that of Dicrocoelium lanceolatum.
Abattoirs↗
From isolates to a synthetic laboratory population: maintenance of variability in the nematode Haemonchus contortus.
Haemonchus contortus isolates were collected from goats of five locations with different climatic characteristics in Guadeloupe archipelago. They were investigated for morphology, morphometrics and allozyme diversity after passage in immunosuppressed lambs using long acting corticoids. The basic aim of the work was to construct a synthetic strain in laboratory conditions which was representative of the isolates. The isolates were only slightly different although climatic conditions were very different. The resemblance of isolates might be due to the practice of goat exchanges between farms or to their insular origin. However the isolate from a smaller island (Les Saintes) was different (mostly on morphometrics) from all the others originating from Guadeloupe main Island. The first assemblage in laboratory resulting from the installation from a mixture of the five isolates was not very representative, whereas the next generation (synthetic strain) resembled all the isolates as shown from allozyme study. Female fecundity and length in established synthetic strain were lower than that recorded in isolates, indicating a decrease in fitness, possibly due to the stability of experimental environment. The representativity of the synthetic strain was good but the strain could still evaluate on further passages and should be evaluated on a large number of generations maintained in laboratory.
Animals↗
Identification of African Paragonimidae by multivariate analysis of the eggs.
A study of metacercariae and adult Paragonimidae revealed the existence in West-Africa of four species, of which two are largely recorded in literature (Paragonimus africanus and Paragonimus uterobilateralis), one was suspected (Paragonimnus westermani-like) and one remained unrecorded in Africa (Euparagonimus sp). Among the two last ones, P. westermani-like was probably confused with P. africanus, and Euparagonimus sp. with P. uterobilateralis. P. westermani-like adult worms differed from P. africanus by the morphology of ovary, testes and the size of the metraterm eggs. Euparagonimus could be identified by a short excretory bladder in metacercariae. The discriminant functions established on eggs measurements (average, maximum and minimum length, average, maximum and minimum width) were able to separate the isolates into four groups. The largest eggs (97 x 59 microm) belonged to P. westermani-like, the medium sized eggs were ascribed to P. africanus (91 x 49 microm) and to Euparagonimus sp. (84 x 50 microm), and the smaller eggs (69 x 42 microm) were identified as P. uterobilateralis. Three Paragonimidae were identified in Cameroon: P. westermani-like, P. africanus and Euparagonimus sp. Additionally, P. uterobilateralis, P. westermani-like, and Euparagonimus sp. were found in the Congo, Gabon, and the Ivory Coast, respectively.
Africa, Western↗
PCR diagnosis of benzimidazole-susceptibility or -resistance in natural populations of the small ruminant parasite, Teladorsagia circumcincta.
We have developed a new molecular tool for the diagnosis of the benzimidazole (BZ)-susceptibility or resistance in Teladorsagia circumcincta a nematode parasite of small ruminants. This tool is based on the use of the PCR and allows the genotyping of resistant (rr) or susceptible (rS and SS) adult worms or larvae. By using four primers in the same reaction mixture, worms can be genotyped in regard to the mutation on the residue 200 (phenylalanine to tyrosine) of the beta-tubulin which is implicated in BZ resistance. A very high proportion of homozygous SS (Phe/Phe) individuals characterized the BZ susceptible populations, whereas a variable proportion of homozygous rr (Tyr/Tyr) individuals characterized the BZ resistant populations. A positive correlation was observed between the LD50 estimated by egg hatch assay, and the proportion of mutant homozygous individuals rr (Tyr/Tyr). Our PCR method allows the rapid genotyping of numerous worms and permits the detection of the first resistant individuals in a worm population.
Animals↗
Analysis of helminth genetic data: comparative examples with Haemonchus contortus isozymes using exact tests or resampling procedures.
Population genetic data on helminths are scarce and it is important to fine tune analyses of these data, the interpretation of which is based on between-(Fst) and within-(Fis) population variability. Several computer programs are available and confidence intervals of each index are based on different procedures. These programs (Genetix, Diploid, Genepop) were compared with a classical program (Biosys-1) using a large set of Haemonchus contortus isozyme data. The results were identical for all softwares for large differences when natural populations were studied (Fst > 0.25 and Fis > 0.15 or <-0.15). When small Fst were investigated in laboratory-reared populations, the significance of differences was often related to the software used. As a rule of thumb, it is suggested that at least two out of three software packages (based on different calculation procedures) should give similar results before differences are validated.
Animals↗
Desiccation tolerance of Muellerius capillaris first-stage larvae from Israeli arid and French temperate habitats and their compatibility to the land snail Theba pisana.
The survival capacities of Muellerius capillaris (Nematoda: Protostrongylidae) free-living larval stages (L1) of an Israeli desert isolate (Nubian isolate) (92 mm rain per annum) and a French isolate from a temperate habitat (650 mm rain per annum) were compared under humid and extreme dry conditions. Under the dry conditions (7% relative humidity [r.h.] and 33% r.h. at 23 degrees C), both isolates exhibited the same remarkable survival capacity for periods of 17 and 28 days, respectively (> 92% survival, P > 0.1). However, during and after recovery from the anhydrobiotic state, different behaviour patterns of L1 were observed in each isolate. Under humid conditions (97% r.h.) for 10 days, both isolates exhibited similarly low survival percentages (13.4 +/- 4.6%, S.E., survival for the Nubian isolate, 3 +/- 3% for the French isolate, P > 0.05). In water, the French isolate was less active, survived better (52 +/- 8.4% vs 28.7 +/- 3.7, by day 28, P < 0.05) and retained a better morphological appearance (shrunk less) than the Nubian isolate. Larval development of the French isolate in the land snail Theba pisana was significantly faster than that of the Nubian isolate, reaching a higher proportion of infective stages (L3) on day 36 post-infection (78.6% vs 56% P > 0.05). However, similar infection intensities were recovered in snails infected with either of the isolates (59.8 +/- 10.3, S.E., n = 14, for the French isolate, 53 +/- 6, n = 13, for the Nubian isolate, P < 0.05).
Animals↗
Description of Haemonchus placei (Place, 1893) (Nematoda, Trichostrongylidae, Haemonchinae), identification and intra-specific morphologic variability.
Haemonchus placei in cattle has never been completely described, possibly due to great morphological similarity with small ruminants Haemonchus contortus. It is newly described on one isolate from Argentina. It has clear distinct morphological features from sheep and goats Haemonchus contortus and presents only two female morphotypes (linguiform and knobbed) instead of three recorded in H. contortus. A key is proposed to identify females. Female as well as male Haemonchus placei from New World (Argentina, Mexico, USA) are morphologically different from those of Old World (Africa: Burkina-Faso, Mauritania and Ivory Coast) or Australia, possibly due to local evolution since their introduction several centuries ago from Africa or India. We propose to differentiate three sub-species, H. placei placei in Australia, H. placei africanus in western Africa and H. placei argentinensis in the New World.
Animals↗
Limited role of lagomorphs (Oryctolagus cuniculus and Lepus capensis) in the dispersion of parasite nematodes of ruminants.
Rabbits (Oryctolagus cuniculus) and hares (Lepus capensis) were investigated under natural conditions for infection with ruminant nematodes, either in the condition of close contact with sheep (south-east of France) or unknown contact with ruminants (central region and French Champaign). Rabbits and hares were poorly infected with sheep digestive tract nematodes: Trichostrongylus colubriformis (second record) was encountered in one site and Trichostrongylus capricola (a first record) in another site, at very low intensity. Small sheep lungworms (Neostrongylus linearis and Cystocaulus ocreatus) were not recorded in rabbits grazing common pasture with sheep. Although transmission remained limited between lagomorphs and ruminants, it could play a role in the transfer of nematode isolates resistant to anthelmintics from one farm to another.
Animals↗
Experimental and natural Haemonchus spp. cross infections of domestic ruminants in Sahelian West Africa.
Explore the source record for details and available documents.
Africa, Western↗
Protostrongylid nematode infection of chamois (Rupicapra rupicapra) at the Bauges massif (French Alps).
From 1979 to 1985, protostrongylid infections (small lungworms) of chamois were studied at the Bauges hunting reserve, in the western Alps. Fifty-two chamois were necropsied on 24 sites and lung nematodes identified to species. From June to November 1985, a more detailed study was undertaken on four sites where chamois were the only ruminants. First-stage larvae excreted in feces and infection of snails intermediate hosts were monitored. The protostrongylid species were, arranged in decreasing order of prevalence, Neostrongylus linearis, Protostrongylus rupicaprae, Muellerius capillaris, and Muellerius tenuispiculatus. Intensity was higher in females than in males (in chamois aged 4 to 11 months compared with younger or older ones) in winter than in the other seasons. Intensity of infection increased as chamois were located at lower altitudes. The snail intermediate hosts were, in decreasing order of importance, Helix pomatia, Cepaea sylvatica and Arianta arbustorum.
Altitude↗
Comparative analysis of two methods used to show interspecific associations in naturally acquired parasite nematode communities from the abomasum of ewes.
The aim of our study was to compare a multivariate and a univariate method to evaluate the associations between nematode species in natural infections. We used a data set based on the 3-year study of the community of abomasal nematodes in ewes of the middle-Atlas region of Morocco. Frequency data (percentage of each species in the individual host community) were processed by principal component analysis. Euclidean distances between species (D2) were calculated from projections of principal component analysis on three axes and compared to a bivariate estimate (1 - correlation coefficient R). Low distances were recorded between morphs of the same species (Teladorsagia circumcincta and T. trifurcata, for example), which indicates a positive association. Only two species, Trichostrongylus axei and T. circumcincta, were negatively associated having D2 values much over 1. The distances D2, i.e., multivariate measure of association intensity were similar in most cases to 1- R estimates, indicating probably the absence of strong multispecies association. The D2 fitted a Motomura geometric progression model indicating that associations were arranged in a continuum from low to high values, but they did not depart much from what could be expected from random associations for most species. The D2 interest is mostly to relate associations with environmental variables, and comparing with 1 - R, to assess the degree of interaction in the community.
Abomasum↗
Stable and unstable environments influence the genetic diversity of the nematode Teladorsagia circumcincta, a parasite of small ruminants.
Acclimation of animal parasitic nematodes in the laboratory is the result of environmental disturbance; moderate numbers of infective larvae are introduced into and develop in a few naive hosts (versus many hosts with a resistance status to parasite infection under natural conditions), and stable conditions such as convenient moisture and temperature (versus the unstable climatic environment in the field) are offered to the free-living stages. The acclimation of sheep and goat lines of the nematode Teladorsagia circumcincta in lambs was arranged in the following putative order of increasing disturbance: sheep line and high success of experimental infection, sheep line and poor success of infection, goat line and high success of infection, sheep line with very poor success of infection, goat line and poor success of infection, and sheep isofemale line with founder and inbreeding effects. The genetic variability was assessed using the enzymes glucose-phosphate isomerase, lactate dehydrogenase, malate dehydrogenase, mannose-phosphate isomerase, and phosphoglucomutase, in starch-gel electrophoresis. The ranking on increasing Fst values (increasing genetic differentiation) observed between initially introduced and twice-passaged generations ranged from 0.003 (sheep line in sheep with high infective success) to 0.19 (sheep isofemale line) and matched to a certain extent with disturbance. The introduction of a goat line in sheep was a major disturbance, whereas in sheep lines the major factor of variation was due to the founder effect, i.e., the effective number of nematodes introduced to seed the acclimated lines. The deficiency in heterozygotes, which remains largely unexplained, was not modified during acclimation. In most cases the introduction of worms from nature resulted in lower overall genetic variability in the subsequent laboratory-reared populations.
Adaptation, Physiological↗
Host range and the maintenance of Haemonchus spp. in an adverse arid climate.
Three Haemonchus species (Haemonchus contortus, Haemonchus placei and Haemonchus longistipes) live in sympatry in Sahelian areas such as Mauritania (West Africa). Four host species (dromedary, zebu cattle, sheep and goats) share the same pastures for several months per year. Experimental infection by H. contortus or H. placei was achieved only poorly in dromedaries, and H. contortus or H. longistipes infection failed to establish in zebu cattle. Conversely, H. placei and H. longistipes successfully infected sheep and goats. Under field conditions, mixed congeneric infections were very rare in dromedaries but frequent in zebu cattle (H. contortus represented 16% of Haemonchus spp. burden), in sheep (H. placei: 15%) and in goats (H. placei: 9% and H. longistipes: 6% of worms). The importance of the different host species was evaluated for Haemonchus spp.: small ruminants are the main hosts of H. contortus, dromedaries harboured the large majority of H. longistipes worms but 5% of them were found in goats which seemed to be additional hosts. The most striking finding was the role played by the small ruminants in the survival strategy of H. placei in Sahelian regions: 56% of the total of H. placei worms were found in sheep, 34% in goats and only 10% in zebu cattle. These results are consistent with the hypothesis that the extension of host range plays an important role in the survival strategy of H. placei, whereas H. longistipes or H. contortus might well survive utilising their usual hosts.
Animals↗
Gastrointestinal and pulmonary nematode infections decrease goat productivity in Moroccan semi-arid conditions.
A herd of goats naturally infected with lungworm and gastrointestinal nematodes was divided into three groups and treated with either morantel tartrate or fenbendazole at strategic periods, i.e. in June (at pre-mating), in November (at pre-kidding) and in January (at early lactation) or left untreated. Morantel tartrate treatment (8 mg kg-1) was efficient in reducing the gastrointestinal nematode egg output and fenbendazole treatment (15 mg kg-1) was efficient in reducing the gastrointestinal nematode egg and small lungworm larvae faecal output. Reductions in mortality of adult goats and their progeny and improvement of rearing percentages were recorded in both treated groups, with fenbendazole showing a greater response than morantel tartrate. A relative risk analysis showed that mortality in goats and kids was significantly reduced in treated kids and goats. Reduction of 6.6% in kidding rates, 0.21 in prolificacy, and an increase of 1.3 in abortion rates, 8.3% in kid and 2.2% in goat mortalities, could be attributable to the small lungworm infection. Small lungworm infections seem therefore to be one of the main causes of indirect kid mortality and inadequate breeding performance of goats in the semi-arid Middle Atlas region of Morocco.
Animals↗
Characterization of Fasciola hepatica redial generations by morphometry and chaetotaxy under experimental conditions.
Morphometric and chaetotactic studies were carried out on the body and cephalic regions of the rediae of Fasciola hepatica (Trematoda: Fasciolidae) in order to precisely identify the different redial generations of this trematode in Lymnaea truncatula under experimental infection. At day 49 post-exposure at 20 degreesC, 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.
Animals↗