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J Cabaret

Publications and source records attributed to J Cabaret.

At least 55 records · Page 3Linked to original sources
PubMed1999

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↗
PubMed1999

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↗
PubMed1999

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↗
PubMed1998

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↗
PubMed1998

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↗
PubMed1998

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↗
PubMed1998

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↗
PubMed1998

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↗
PubMed1998

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↗
PubMed1998

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↗
PubMed1998

Morphological variability in Fasciola hepatica eggs in ruminants, rodents and lagomorphs.

The length and width of 1297 Fasciola hepatica eggs shed in cattle hosts, 337 in sheep and 199 in nutria, were measured from several parts of France. The data were compared with those obtained from other studies in Spain, France (where rats were also investigated), Germany and the Netherlands. One way analysis of variance and discriminant analysis were used to assess differences between host origins. The distribution of length and width of eggs were analysed using skewness and kurtosis Fisher coefficients. The eggs recovered from sheep, cattle, rodents and lagomorphs were different in size: the eggs found in rodents (length L x width W in microm: 8592) and lagomorphs (L x W in microm: 9100) were smaller than those found in sheep and cattle (L x W in microm: 10,000). These morphological differences in F. hepatica eggs were host-induced in rats (L x W in microM: 9709 in cattle to 8949 in rats) and rabbits (L x W in microm: 9709 in cattle to 8432 in rabbits). These differences in size of eggs might correspond to their being less able to develop into miracidia in less frequent hosts such as rodents and rabbits.

Analysis of Variance↗
PubMed1998

Faecal egg counts are representative of digestive-tract strongyle worm burdens in sheep and goats.

The relationship between faecal egg counts and worm burdens in sheep and goats was studied in a large array of environments, from temperate (ewes, lambs or dairy-goats in France) or steppic (ewes in Middle-Atlas of Morocco) to Sahelian (young sheep and goats of Mauritania in West Africa) climates. The studied temperate worm communities were dominated by Teladorsagia and Trichostrongylus sp., and those from steppic areas by Teladorsagia, Marshallagia and Trichostrongylus sp.; Haemonchus contortus was highly predominant in the Sahelian regions. The fertility of worms depended on density (10 to 50% of variance) and presence of H. contortus to a lesser extent. For sheep and goats from several temperate and steppic areas, a good relationship between egg counts and worm burdens was established (r = 0.62). It was ameliorated when the percentage of H. contortus, the most prolific species was incorporated in the model. The predictive value of faecal egg count for assessing worm burden was only of interest for groups of hosts.

Age Factors↗
PubMed1998

Unusual transmission of the liver fluke, Fasciola hepatica, by Lymnaea glabra or Planorbis leucostoma in France.

Cases of fasciolosis in ruminants have been recorded in several French farms in the absence of Lymnaea truncatula, which is considered the only snail intermediate host in western Europe. These farms harbored other species of freshwater snails in large numbers (Lymnaea glabra, Physa acuta, or Planorbis leucostoma) and, in many cases, had cattle or sheep infected by another trematode (Paramphistomum daubneyi). These other freshwater snails may serve as intermediate hosts for F. hepatica due to a coexisting infection with P. daubneyi. We have demonstrated that L. glabra, either infected with F. hepatica alone or coinfected by P. daubneyi, was capable of developing a F. hepatica infection. A broader range of L. glabra size classes (up to 10 mm in height) were susceptible to infection if simultaneously infected with P. daubneyi. Planorbis leucostoma can only serve as an intermediate host for F. hepatica, if infected with P. daubneyi. Lastly, P. acuta smaller than 4 mm cannot serve as an intermediate host. These results may explain, in part, the maintenance of low-level F. hepatica infections in the absence of the normal intermediate host, L. truncatula.

Animals↗
PubMed1997

Identification of Haemonchus species in domestic ruminants based on morphometrics of spicules.

An easy and rapid tool for the individual identification of Haemonchus species in domestic ruminants might be very useful in the study of natural populations, especially when two (or three) species are sympatric. Techniques based on cytology, cuticular-ridge patterns, sublateral hypodermic chords, or molecular biology allow species identification but are either expensive or time-consuming. Therefore, a discriminant function combining three measures of male spicules was established from experimental infections with H. contortus in both sheep and goats and with H. placei in zebu. The discriminant function was evaluated on individual worms and on average values obtained in natural and experimental populations throughout the world. It was compared with a previously established function. The use of our function permitted better species identification for all Haemonchus species of ruminants, including H. longistipes from camels and H. similis from cattle.

Analysis of Variance↗
PubMed1997

Fasciola hepatica: in vitro production of daughter rediae and cercariae from first- and second-generation rediae.

Fasciola hepatica mother rediae belonging to the first generation and the first cohort of the second generation were extracted from their snail intermediate host (Lymnaea truncatula) and maintained in vitro for 16 days to determine the quantity of daughter rediae and cercariae produced by each generation. L-15 Leibovitz medium with a saline fraction adjusted to that of the L. truncatula hemolymph was used for experiments. A total of 35 daughter rediae exited from the 21 mother rediae of the first and second generations, which were 14-32 days old at the onset of culture. Microscope examination of the mother rediae demonstrated the presence of numerous redial embryos and differentiating daughter rediae, whereas no cercaria was seen within their body. A total of 49 cercariae exited from the 17 mother rediae of the first and second generations, which were 29-50 days old at the onset of culture. No differentiating daughter redia was seen in these last mother rediae. The productivity of the first or second generation (first cohort) was nearly identical in terms of cercariae.

Animals↗
PubMed1997

Bronchoalveolar cellular responses of goats following infections with Muellerius capillaris (Protostrongylidae, Nematoda).

The development of Muellerius capillaris in the lung of goats was associated with marked tissue damage and pronounced a cellular reaction. Using broncho-alveolar lavage, the time course of the cellular responses was studied following primary and secondary infection. During the primary infection, there was a biphasic increase in total broncho-alveolar leucocytes (an average of 294.0 +/- 137.0 cells microl[-1]) and in the absolute number of macrophages (182.0 +/- 82.0 cells ul[-1]), lymphocytes (68.5 +/- 35.0 cells microl[-1]), eosinophils (35.3 +/- 16.4 cells microl[-1]) and neutrophils (10.9 +/- 8.7 cell microl[-1]). The lung tissue reaction against worms consisted of a mild infiltration of inflammatory cells. The secondary infection resulted in significant changes in the pulmonary tissue characterised by severe inflammation, leading to widespread granulomatous formation throughout the parenchyma, hyperplasia of cells Type II and a leucocytosis in the broncho-alveolar fluids, with an anamnestic-like response by all cell types. The overall average of the total leucocytes, macrophages, lymphocytes, eosinophils and neutrophils was 529.3 +/- 347.4; 265.4 +/- 148.1; 127.3 +/- 100; 125.4 +/- 100.1 and 14.0 +/- 8.7 cells microl(-1), respectively. Secondary infection also resulted in 56% reduction of worms established in the lungs and 72.3% of L1 larval production. These data suggest that the broncho-alveolar leucocyte response to infection has an immunological basis and that the alveolar macrophages, neutrophils, eosinophils, and lymphocytes may play a significant role in lung resistance against protostrongylid nematodes.

Animals↗
PubMed1997

Assessment of the severity of natural infections of kids and adult goats by small lungworms (Protostrongylidae, Nematoda) using macroscopic lesion scores.

Assessment of the severity of natural infections of kids and adult goats by small lungworms using macroscopic lesion scores was carried out on 476 lungs originating from the Rabat area of Morocco. The prevalence of infection was 98% in kids and 100% in adult goats. The diaphragmatic lobes were the preferential site for protostrongylids. The average number of nodules (mostly Muellerius capillaris) and lobular lesions (mostly Protostrongylus rufescens and Cystocaulus ocreatus) was 174 and 9 per pair of lungs respectively, indicating that the amount of lung tissue rendered inactive in heavy infections was considerable. Up to 19.9% kids or 34.2% adult goats had heavy infection based on nodular lesions (more than 200 nodules); 61% and 68% of kids and adult goats respectively had heavy infection based on lobular lesions (more than four lobular lesions per pair of lungs). The proportion of the total lung surface occupied by protostrongylid lesions was 35.1% in kids and 23.5% in adult goats, suggesting that small lungworm infections may significantly contribute to the debilitation of infected caprines in the area.

Abattoirs↗