Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 46
Filter
1.
Food Waterborne Parasitol ; 30: e00188, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36718346

ABSTRACT

Fasciolosis is a re-emergent parasitic disease of worldwide significance with a major global impact on livestock health and production. In the French Mediterranean island of Corsica, fasciolosis has been recognized for a long time but little is known about its dynamic as the main investigations are outdated. Three compartments - definitive domestic hosts, intermediate hosts and environment - involved in fasciolosis transmission were studied by applying an integrative and extensive approach: (1) farm and abattoir surveys, (2) snail sampling, identification and infection prospection, and (3) snail habitat analysis; and (4) a questionnaire-based survey to inquire about husbandry practices and environmental risks. Our results indicate a significant circulation of the liver flukes in Corsican livestock, with 90% (252/279) of the sampled farms testing positive for anti-F. hepatica antibodies. At the abattoir, 46% (67/149) of cattle were positive for F. hepatica antibodies and eggs were present in the bile of 19% (26/139) bovines. In addition, high prevalence of Dicrocoelium dendriticum (69%) was observed in slaughtered cattle. Malacological surveys registered the occurrence of several lymnaeid species in a variety of habitats throughout the island. In particular, we report for the first time the presence of the invasive lymnaeid snail Pseudosuccinea columella in Corsica, a potential intermediate host for F. hepatica. We also found that the presence of Galba truncatula and, to a lesser extent, that of Peregriana peregra, is associated with altitude. Fasciola hepatica DNA was detected in the latter species occurring at two different sites. Finally, a questionnaire-based study revealed risky management practices among Corsican farmers, low perception of transmission and a suboptimal use of flukicide treatments as main control strategy. Our results show that animal fasciolosis in Corsica is characterised by a significant circulation and a favourable epidemiological scenario for transmission to occur.

2.
Vet Parasitol Reg Stud Reports ; 28: 100687, 2022 02.
Article in English | MEDLINE | ID: mdl-35115120

ABSTRACT

Cyathostomins are considered as the most prevalent and pathogenic parasites of grazing horses. The development on pastures of the free-living stages of these gastrointestinal worms is particularly influenced by outdoor temperature. Understanding the bionomics of free-living stages is an important prerequisite to implement mathematical models designed to assess the parasitic risk for grazing equids. The aim of this study was to assess the effect of 3 constant temperatures under laboratory conditions (10 ± 1 °C, 23 ± 2 °C, 30 ± 2 °C) and one fluctuating temperature under outdoor conditions (mean: 17 ± 4 °C) on the minimum time taken by cyathostomin eggs to develop into first/second stage larvae (L1/L2) then into infective third stage larvae (L3) in horse faeces. According to the temperatures, the minimum time taken by eggs to develop into L1/L2 was between 1 and 3 days and into L3 between 4 and 22 days. At 10 °C, the development time of eggs into L3 was the longest and at 30 °C the fastest. The results were consistent with historically available data and their compilation should lead to the improvement of parameterised models assessing the parasitic risk period in grazing equids.


Subject(s)
Temperature , Animals , Feces/parasitology , Horses , Larva
3.
Prog Urol ; 31(10): 557-575, 2021 Sep.
Article in English | MEDLINE | ID: mdl-34154957

ABSTRACT

INTRODUCTION: No recent national guidelines exist regarding the management of urinary tract infections (UTIs) in the presence of ureteral stent. This situation could lead to discrepancies in clinical management and less opportunity for a favorable patient's outcome. METHODS: All available data published on Medline® between 1998 and 2018 were systematically searched and reviewed. All papers assessing adult patients carrying ureteral stent were included for analysis. After studies critical analysis, national guidelines for clinical management were elaborated in order to answer clinical questions. RESULTS: A total of 451 articles were identified, of which 58 have been included. The prevalence of urinary tract infections in the presence of ureteral stent remains unknown. After 3 months, all endo-ureteral devices were colonized on microbiological study. These patients also presented a positive urine culture in 25 to 70% of the cases, often polymicrobial. Staphylococci, E. coli, Klebsiella, Pseudomonas, Enterococcus and Candida were the commonest micro-organisms responsible for urinary colonization or infection. The risk of UTI on endo-ureteral devices seemed higher the longer it stayed implanted. There is no justification in the literature to recommend a systematic change of endo-ureteral devices following a urinary tract infection. DISCUSSION: The existing literature is rich but of poor methodological quality, and therefore does not allow to draw robust conclusions. The greatest difficulty faced in this work was to accurately differentiate urinary colonizations from true infections, including clinical symptoms and not only microbiological results. CONCLUSION: These guidelines propose a standardized management of such common clinical situations. Well-designed studies are needed to upgrade the level of evidence of these guidelines.


Subject(s)
Communicable Diseases , Ureter , Urinary Tract Infections , Adult , Escherichia coli , Humans , Stents , Urinary Tract Infections/diagnosis , Urinary Tract Infections/epidemiology , Urinary Tract Infections/etiology
4.
Anaesth Crit Care Pain Med ; 39(2): 279-289, 2020 04.
Article in English | MEDLINE | ID: mdl-32229270

ABSTRACT

OBJECTIVES: To update the French guidelines on the management of trauma patients with spinal cord injury or suspected spinal cord injury. DESIGN: A consensus committee of 27 experts was formed. A formal conflict-of-interest (COI) policy was developed at the outset of the process and enforced throughout. The entire guidelines process was conducted independently of any industrial funding (i.e. pharmaceutical, medical devices). The authors were advised to follow the rules of the Grading of Recommendations Assessment, Development and Evaluation (GRADE®) system to guide assessment of quality of evidence. The potential drawbacks of making strong recommendations in the presence of low-quality evidence were emphasised. METHODS: The committee studied twelve questions: (1) What are the indications and arrangements for spinal immobilisation? (2) What are the arrangements for pre-hospital orotracheal intubation? (3) What are the objectives of haemodynamic resuscitation during the lesion assessment, and during the first few days in hospital? (4) What is the best way to manage these patients to improve their long-term prognosis? (5) What is the place of corticosteroid therapy in the initial phase? (6) What are the indications for magnetic resonance imaging in the lesion assessment phase? (7) What is the optimal time for surgical management? (8) What are the best arrangements for orotracheal intubation in the hospital environment? (9) What are the specific conditions for weaning these patients from mechanical ventilation for? (10) What are the procedures for analgesic treatment of these patients? (11) What are the specific arrangements for installing and mobilising these patients? (12) What is the place of early intermittent bladder sampling in these patients? Each question was formulated in a PICO (Patients, Intervention, Comparison, Outcome) format and the evidence profiles were produced. The literature review and recommendations were made according to the GRADE® Methodology. RESULTS: The experts' work synthesis and the application of the GRADE method resulted in 19 recommendations. Among the recommendations formalised, 2 have a high level of evidence (GRADE 1+/-) and 12 have a low level of evidence (GRADE 2+/-). For 5 recommendations, the GRADE method could not be applied, resulting in expert advice. After two rounds of scoring and one amendment, strong agreement was reached on all the recommendations. CONCLUSIONS: There was significant agreement among experts on strong recommendations to improve practices for the management of patients with spinal cord injury.


Subject(s)
Intubation, Intratracheal , Spinal Cord Injuries , France , Humans , Respiration, Artificial , Resuscitation , Spinal Cord Injuries/therapy
5.
J Helminthol ; 94: e125, 2020 Feb 10.
Article in English | MEDLINE | ID: mdl-32036795

ABSTRACT

Our objective was to measure the efficacy of ivermectin (IVM) and benzimidazoles (BZ, i.e. fenbendazole and albendazole) in 15 cattle farms in western France and southern Italy. A total of 11 groups were treated with IVM and 11 with BZ. Efficacy was assessed by calculating the percentage of faecal egg count reduction (%FECR) using the pre- and post-treatment arithmetic means. Anthelmintic resistance was considered to be present when the %FECR was <95% and the lower limit of the 95% confidence interval <90%. For IVM, the percentages of FECR ranged from 73% to 100%. Lack of efficacy to IVM was detected in two farms out of four in France, but was not detected in any of the seven farms in Italy. For BZ, the percentages of FECR ranged from 95% to 100%. No case of BZ resistance was detected in the five farms in France and the six farms in Italy.


Subject(s)
Anthelmintics/therapeutic use , Cattle Diseases/drug therapy , Gastrointestinal Diseases/veterinary , Nematoda/drug effects , Nematode Infections/veterinary , Animals , Benzimidazoles/therapeutic use , Cattle , Cattle Diseases/parasitology , Farms , Feces/parasitology , France , Gastrointestinal Diseases/drug therapy , Gastrointestinal Diseases/parasitology , Gastrointestinal Tract/parasitology , Italy , Ivermectin/therapeutic use , Nematode Infections/drug therapy , Parasite Egg Count
6.
Cancer Radiother ; 23(4): 312-315, 2019 Jul.
Article in French | MEDLINE | ID: mdl-31147172

ABSTRACT

PURPOSE: To report the results of Botulinum Toxin A (BTA) for radiation-induced head and neck pain. MATERIALS AND METHODS: This single-center retrospective study included all the patients treated at our institution with botulinum toxin A injections for radiation-induced head and neck pain between 2006 and 2017. Pain was evaluated by each patient on a visual analogue scale (VAS) (between 0 and 10) before, and 1 month after the injection. RESULTS: Sixteen patients were included in this series. The mean value of the pain was 8.5 before and 8 after the first injection. The difference was statistically significant (p<0.01). Major response occurred in 15 patients (VAS≤3 after BTA) and complete response in 11 patients (VAS=0 after BTA). CONCLUSION: Botulinum toxin is an effective treatment for radiation-induced head and neck pain.


Subject(s)
Botulinum Toxins, Type A/therapeutic use , Neck Pain/drug therapy , Neuromuscular Agents/therapeutic use , Radiotherapy/adverse effects , Adult , Aged , Electromyography , Female , Head and Neck Neoplasms/radiotherapy , Humans , Injections, Intramuscular , Male , Middle Aged , Neck Pain/etiology , Retrospective Studies , Visual Analog Scale
7.
Animal ; 12(5): 1030-1040, 2018 May.
Article in English | MEDLINE | ID: mdl-28988555

ABSTRACT

The suitability of a single mid-season targeted selective treatment (TST) for gastrointestinal nematodes control, based on flexible average daily weight gain (ADWG) thresholds, was investigated in 23 groups of first grazing season calves. In each group, animals were weighed three times: before turnout, at mid-season and at housing. Just after the first weighing, each group was divided in two homogenous sub-groups in terms of age, breed and weight, and randomly allocated to one of two sub-groups intented for two different mid-season anthelmintic treatment strategies: (1) a treatment of all calves composing the sub-group (whole-group treatment (WT)) or (2) a targeted selective weight gain-based treatment (TST) of the animals showing an individual pre-treatment ADWG inferior to the mean pre-treatment ADWG of the corresponding WT sub-group. Anthelmintic treatment (levamisole 7.5 mg/kg BW) was performed 3 to 4 months after turnout. At housing, two parasitological parameters (the anti-Ostertagia ostertagi antibody level-Ostertagia optical density ratio (ODR) and the pepsinogen level) and a clinical parameter (the breech soiling score) were assessed at individual level in each group. Then, the high exposed groups to gastrointestinal nematode (GIN) were defined as groups for which untreated animals exhibited a mean Ostertagia ODR ⩾0.7 and among these groups, the ones characterized by high abomasal damage due to Ostertagia for which untreated animals exhibited a mean pepsinogen level ⩾2.5 U Tyr were also identified. Among TST sub-groups, the treatment ADWG thresholds varied from 338 to 941 g/day and the percentage of treated animals from 28% to 75%. Pre- and post-treatment ADWG as well as parasitological and clinical parameters measured at housing were similar between TST and WT sub-groups including the 17 high exposed groups to GIN. Within these 17 groups, the treatment allowed to significantly improve post-treatment ADWG compared with untreated animals. In the six high exposed groups showing mean pepsinogen level ⩾2.5 U Tyr, the average effect of treatment on post-treatment ADWG was the highest and estimated up to 14 kg after a grazing duration of 4 months. In contrast, in six other groups showing mean Ostertagia ODR<0.7 in untreated animals, no effect of treatment was seen suggesting an absence of production losses related to a low level of GIN infection. This study highlighted the suitability of a convenient mid-season TST strategy for first grazing season calves, based on the use of flexible thresholds of ADWG, allowing similar growth compared with a whole-group treatment while keeping a GIN population in refugia.


Subject(s)
Anthelmintics/therapeutic use , Cattle Diseases/prevention & control , Nematoda/drug effects , Nematode Infections/veterinary , Abomasum/drug effects , Abomasum/parasitology , Animals , Body Weight/drug effects , Cattle , Cattle Diseases/parasitology , Dairying , Female , Nematode Infections/parasitology , Nematode Infections/prevention & control , Ostertagia/drug effects , Ostertagiasis/parasitology , Ostertagiasis/prevention & control , Ostertagiasis/veterinary , Pepsinogen A/analysis , Random Allocation , Seasons , Weight Gain/drug effects
8.
Neuroimage ; 153: 307-318, 2017 06.
Article in English | MEDLINE | ID: mdl-28389385

ABSTRACT

Transcranial Magnetic Stimulation (TMS) established itself as a powerful technique for probing and treating the human brain. Major technological evolutions, such as neuronavigation and robotized systems, have continuously increased the spatial reliability and reproducibility of TMS, by minimizing the influence of human and experimental factors. However, there is still a lack of efficient set-up procedure, which prevents the automation of TMS protocols. For example, the set-up procedure for defining the stimulation intensity specific to each subject is classically done manually by experienced practitioners, by assessing the motor cortical excitability level over the motor hotspot (HS) of a targeted muscle. This is time-consuming and introduces experimental variability. Therefore, we developed a probabilistic Bayesian model (AutoHS) that automatically identifies the HS position. Using virtual and real experiments, we compared the efficacy of the manual and automated procedures. AutoHS appeared to be more reproducible, faster, and at least as reliable as classical manual procedures. By combining AutoHS with robotized TMS and automated motor threshold estimation methods, our approach constitutes the first fully automated set-up procedure for TMS protocols. The use of this procedure decreases inter-experimenter variability while facilitating the handling of TMS protocols used for research and clinical routine.


Subject(s)
Neuronavigation/methods , Transcranial Magnetic Stimulation/methods , Adult , Bayes Theorem , Evoked Potentials, Motor , Female , Humans , Male , Motor Cortex/physiology , Muscle, Skeletal/innervation , Muscle, Skeletal/physiology , Reproducibility of Results , Young Adult
9.
Ann Fr Anesth Reanim ; 33(4): 279-81, 2014 Apr.
Article in French | MEDLINE | ID: mdl-24704099

ABSTRACT

A 78-year-old man was admitted in the intensive care unit for epilepsy seizure (tonic-clonic seizure). Since three months, his wife reports motor dysfunction (weakness) and since two weeks, rapidly progressive changes in cognition (apraxia, akinetic mutism). The diagnosis of probable sporadic Creutzfeldt-Jakob on the basis of clinical, EEG and MRI lesions was made. Refining diagnostic criteria is probably needed, including the usefulness of repeated MRI with FLAIR and diffusion-weighted imaging.


Subject(s)
Creutzfeldt-Jakob Syndrome/diagnosis , Status Epilepticus/diagnosis , Aged , Cognition Disorders/etiology , Diagnosis, Differential , Electroencephalography , Epilepsy, Tonic-Clonic/etiology , Humans , Magnetic Resonance Imaging , Male , Muscle Weakness/etiology
10.
Vet Parasitol ; 201(1-2): 95-109, 2014 Mar 17.
Article in English | MEDLINE | ID: mdl-24468428

ABSTRACT

To investigate future tools for targeted selective treatment against gastrointestinal nematodes (GIN) in adult dairy cows, we evaluated herd and individual cow factors associated with the post-treatment milk production (MP) response over time. A field trial involving 20 pasturing dairy herds in Western France was conducted in autumn 2010 and autumn 2011. In each herd, lactating cows were randomly allocated to a treatment group (fenbendazole) (623 cows), or a control group (631 cows). Daily cow MP was recorded from 2 weeks before until 10 to 14 weeks after treatment. Individual serum anti-Ostertagia antibody levels (expressed as ODR), pepsinogen levels, faecal egg count (FEC), and bulk tank milk ODR were measured at the time of treatment. Moreover, in each herd, information regarding heifers' grazing and treatment history was collected to assess the Time of Effective Contact (TEC, expressed in months) with GIN infective larvae before the first calving. TEC was expected to reflect the development of immunity against GIN, and TEC=8 months was a cautious threshold over which the resistance to re-infection was expected to be established. Daily MP averaged by week was analyzed using linear mixed models with three nested random effects (cow within herd and herd within year). The overall treatment effect was significant but slight (maximum=+0.85 kg/d on week 6 after treatment), and the evolution of treated cows' MP differed significantly according to several factors. At the herd level, cows from low-TEC herds responded better than cows from high-TEC (≥ 8 months) herds; cows from herds in which the percentage of positive FEC was >22.6% (median value) responded better than those from herds where it was lower. At the individual cow level, primiparous cows, cows with days in milk (DIM) < or = 100 at the time of treatment, and cows with low individual ODR (< or = 0.38) responded better than multiparous cows, cows with DIM>100, and cows with higher ODR, respectively. These results highlight the variability of the treatment response, suggesting that whole herd anthelmintic treatment are not always appropriate, and propose promising key criteria for targeted selective treatment for GIN in dairy cows. Particularly, the TEC is an original criterion which lends support for a simultaneous on-farm qualitative analysis of grazing management factors.


Subject(s)
Antinematodal Agents/therapeutic use , Cattle Diseases/drug therapy , Feeding Behavior , Lactation/drug effects , Nematode Infections/veterinary , Animals , Cattle , Dairying , Feces/parasitology , Female , Nematode Infections/drug therapy , Parasite Egg Count , Treatment Outcome
11.
J Environ Manage ; 133: 184-92, 2014 Jan 15.
Article in English | MEDLINE | ID: mdl-24374467

ABSTRACT

Sustainability is a key driver for decisions in the management and future development of industries. The World Commission on Environment and Development (WCED, 1987) outlined imperatives which need to be met for environmental, economic and social sustainability. Development of strategies for measuring and improving sustainability in and across these domains, however, has been hindered by intense debate between advocates for one approach fearing that efforts by those who advocate for another could have unintended adverse impacts. Studies attempting to compare the sustainability performance of countries and industries have also found ratings of performance quite variable depending on the sustainability indices used. Quantifying and comparing the sustainability of industries across the triple bottom line of economy, environment and social impact continues to be problematic. Using the Australian dairy industry as a case study, a Sustainability Scorecard, developed as a Bayesian network model, is proposed as an adaptable tool to enable informed assessment, dialogue and negotiation of strategies at a global level as well as being suitable for developing local solutions.


Subject(s)
Dairying , Environment , Industry , Bayes Theorem
12.
Rev Med Interne ; 33(5): 284-7, 2012 May.
Article in French | MEDLINE | ID: mdl-22405324

ABSTRACT

INTRODUCTION: Tropical sprue is a postinfective malabsorption syndrome that occurs in some tropical endemic areas. CASE REPORT: A 65-year-old Caucasian patient, with no significant past medical history, living in Cambodia for 10 years, presented with a 23 kg weight loss and chronic diarrhea. Clinical examination was unremarkable. Laboratory tests showed a moderate nutritional deficiency syndrome. The upper gastrointestinal endoscopy showed duodenal villous atrophy and histological analysis confirmed subtotal villous atrophy with important intraepithelial lymphocytosis. The diagnosis of tropical sprue was considered on the epidemiological, clinical and biological context, and the absence of other cause of villous atrophy. A three-month duration treatment with antibiotics, folic acid and vitamin B12 was initiated. The clinical course was favorable with disappearance of diarrhea in 15 days. One year later, the patient had resumed his usual weight, and laboratory tests and duodenal biopsies were normal. CONCLUSION: The diagnosis of tropical sprue should be systematically discussed in any malabsorption syndrome with villous atrophy in a patient living or having lived in the tropics.


Subject(s)
Sprue, Tropical , Aged , Cambodia , Humans , Male , Sprue, Tropical/diagnosis , Sprue, Tropical/drug therapy
13.
Int J Parasitol ; 41(2): 183-92, 2011 Feb.
Article in English | MEDLINE | ID: mdl-20946897

ABSTRACT

Host-parasite interactions may select for significant novel mutations with major evolutionary consequences for both partners. In poor active dispersers such as ticks, their population structures are shaped by their host movements. Here, we use population genetics and phylogeography to investigate the evolutionary history of the most common tick in Europe, Ixodes ricinus, a vector of pathogenic agents causing diseases in humans and animals. Two mitochondrial and four nuclear genes were sequenced for 60 individuals collected on four geographical scales (local, regional, Eurasian and western Palearctic scales). The overall level of nucleotide diversity was low and the variability did not differ at the local, regional or Eurasian scales but increased two fold for the western Palearctic scale. Moreover, the phylogenetic trees indicated an absence of genetic structure among Eurasian ticks, contrasting with a strong differentiation of the north-African ticks which formed a divergent clade. The homogeneity in Eurasian ticks may be explained by gene flows due to passive dispersal of ticks by hosts within a continuous population and recent range expansion of I. ricinus as shown by the fit of the observed frequency distribution of numbers of mismatches between pairwise sequences with the demographic expansion model (Harpending raggedness index, P=0.74). The genetic divergence of the north-African populations could be explained by genetic drift in these small populations that are geographically isolated and/or selection pressures due to different ecological conditions (seasonal activity, pathogenic agents and hosts communities). The consequences of these results on the epidemiology of vector-borne diseases are discussed.


Subject(s)
Ixodes/classification , Ixodes/genetics , Polymorphism, Genetic , Africa, Northern , Animals , Asia , Chromosomes , DNA, Mitochondrial/genetics , Europe , Genetics, Population , Geography , Molecular Sequence Data , Phylogeny , Sequence Analysis, DNA
14.
J Neurophysiol ; 104(4): 2249-56, 2010 Oct.
Article in English | MEDLINE | ID: mdl-20702742

ABSTRACT

Providing evidence against a dissociation between conscious vision for perception and unconscious vision for action, recent studies have suggested that perceptual and motor decisions are based on a unique signal but distinct decisional thresholds. The aim of the present study was to provide a direct test of this assumption in a perceptual-motor dual task involving arm movements. In 300 trials, 10 participants performed speeded pointing movements toward a highly visible target located at 10° from the fixation point and ± 45° from the body midline. The target was preceded by one or two close to threshold distractor(s) (80 ms stimulus onset asynchrony) presented ± 30° according to the target location. After each pointing movement, participants judged whether the distractor was present or not on either side of the target. Results showed a robust reaction time facilitation effect and a deviation toward the distractor when the distractor was both present and consciously perceived (Hit). A small reaction time facilitation was also observed when two distractors were physically present but undetected (double-miss)--this facilitation being highly correlated with the physical contrast of the distractors. These results are compatible with the theory proposing that perceptual and motor decisions are based on a common signal but emerge from a contrast dependent fixed threshold for motor responses and a variable context dependent criterion for perceptual responses. This paper thus extends to arm movement control previous findings related to oculomotor control.


Subject(s)
Attention/physiology , Movement/physiology , Photic Stimulation/methods , Psychomotor Performance/physiology , Visual Perception/physiology , Adult , Female , Humans , Male , Photic Stimulation/instrumentation , Reaction Time/physiology , Sensory Thresholds/physiology
15.
Mol Biochem Parasitol ; 174(1): 36-43, 2010 Nov.
Article in English | MEDLINE | ID: mdl-20603159

ABSTRACT

Babesia divergens, a tick-borne protozoan parasite of red blood cells, is the main agent of bovine and human babesiosis in Europe. Very few data are available concerning its life cycle and sexual reproduction inside the tick vector, Ixodes ricinus. The aim of this study was to define some markers of the B.divergens sexual stage. An in silico post-genomic approach was used to analyze genomic, transcriptomic and proteomic data and to select specific sexual stage proteins of the related apicomplexan genus Plasmodium. Three proteins, based on sequence identity between the available genomes of Plasmodium and Babesia spp., were chosen, as members of a highly conserved and apicomplexan sexual stages specific protein family (CCp) potentially involved in adhesive functions. Degenerate primers were used to amplify and clone three B.divergens orthologs (bdccp1, bdccp2, and bdccp3) corresponding to newly identified genes in this parasite. The opportunities offered by such markers to study parasite development in its vector are discussed.


Subject(s)
Babesia/growth & development , Babesia/genetics , Ixodes/parasitology , Protozoan Proteins/genetics , Animals , DNA, Protozoan/chemistry , DNA, Protozoan/genetics , Genetic Markers , Molecular Sequence Data , Sequence Analysis, DNA , Virulence Factors/genetics
16.
Parasitology ; 137(6): 927-38, 2010 May.
Article in English | MEDLINE | ID: mdl-20109252

ABSTRACT

Babesia sp. BQ1 (Lintan) is a Babesia isolated from sheep infested with Haemaphysalis qinghaiensis in China, and is closely related to B. motasi based on the 18S rRNA gene sequence. In the present study, an ELISA was developed with merozoite antigens of Babesia sp. BQ1 (Lintan) (BQMA) purified from in vitro culture. When the positive threshold was chosen as 30% of the antibodies rate, evaluated with 198 negative sera, the specificity was 95.5%. Except for Babesia sp. Tianzhu, there was no cross-reaction between BQMA and positive sera from Babesia sp. BQ1 (Ningxian)-, Babesia sp. Hebei-, Babesia sp. Xinjiang-, Theileria luwenshuni-, T. uilenbergi-, or Anaplasma ovis-infected sheep, which are the dominant haemoparasites of small ruminants in China. Specific antibodies against Babesia sp. BQ1 (Lintan) were produced 1 or 2 weeks post-infection and a high level of antibodies persisted for more than 8 months in experimentally infected sheep. This ELISA was tested on 974 sera collected from field-grazing sheep in 3 counties of Gansu province, northwestern China to evaluate the seroprevalence of Babesia sp. BQ1 (Lintan) infection and the average positive rate was 66.84%. The feasibility of increasing the specificity of this BQMA-based ELISA, by using some BQMA antigens for serodiagnosis is discussed.


Subject(s)
Babesia/metabolism , Merozoites/metabolism , Protozoan Proteins/metabolism , Animals , Antibodies, Protozoan/blood , Babesia/genetics , Babesiosis/veterinary , Enzyme-Linked Immunosorbent Assay/veterinary , Gene Expression Regulation/physiology , Protozoan Proteins/genetics , Reproducibility of Results , Sensitivity and Specificity , Serologic Tests/veterinary , Sheep , Sheep Diseases/blood , Sheep Diseases/diagnosis , Sheep Diseases/parasitology
17.
Parasite Immunol ; 32(2): 143-52, 2010 Feb.
Article in English | MEDLINE | ID: mdl-20070828

ABSTRACT

Ovine babesiosis is an important disease in China and responsible for economic losses. Several Babesia strains are involved, but Babesia sp. BQ1 (Lintan) and Babesia sp. BQ1 (Ningxian) are particularly prevalent in the Guansu region. Babesia divergens, in contrast, can experimentally infect spleen-intact sheep, but does not induce clinical signs. The immune response of spleen-intact sheep to Babesia sp. BQ1 (Lintan) and to B. divergens was therefore compared to identify the immune mechanisms involved in pathogenicity. The greater pathogenicity of Babesia sp. BQ1 (Lintan) than that of B. divergens was confirmed: sheep infected with Babesia sp. BQ1 (Lintan), but not with B. divergens, developed hyperthermia and showed patent parasitaemia in Giemsa-stained blood smears from the ear vein. Furthermore, more parasites were also detected in the blood from the jugular vein of Babesia sp. BQ1 (Lintan)-infected sheep. Pathogenicity of Babesia spp. involved cellular responses, but not humoral responses. Interferon-gamma was produced only by specifically activated PBMC from B. divergens-infected sheep and interleukin-10 only by specifically activated PBMC from Babesia sp. BQ1 (Lintan)-infected sheep. The role of these cytokines in the course of infection by Babesia spp. is discussed.


Subject(s)
Babesia/pathogenicity , Babesiosis/veterinary , Interferon-gamma/immunology , Interleukin-10/immunology , Sheep Diseases/pathology , Sheep Diseases/parasitology , Animals , Babesia/immunology , Babesiosis/immunology , Babesiosis/pathology , Cells, Cultured , China , Fever , Humans , Interferon-gamma/toxicity , Interleukin-10/toxicity , Leukocytes, Mononuclear/immunology , Parasitemia , Sheep Diseases/immunology
18.
Parasitology ; 134(Pt 2): 197-207, 2007 Feb.
Article in English | MEDLINE | ID: mdl-17076925

ABSTRACT

Although Babesia divergens is the the principal confirmed zoonotic Babesia sp. in Europe, there are gaps in our knowledge of its biology and transmission by the tick Ixodes ricinus. In order to reproduce the part of the parasite cycle that occurs in the vector, an in vitro animal skin feeding technique on blood containing in vitro cultivated B. divergens was developed. Parasite DNA was detected in all samples of salivary glands of nymphs and adults that had fed on parasitized blood as larvae and nymphs, respectively, indicating acquisition as well as a transtadial persistence of B. divergens. PCR performed on eggs and larvae produced by females that had fed on parasitized blood demonstrated the existence of a transovarial transmission of the parasite. Gorging B. divergens infected larvae on non-infected gerbils showed persistance of the parasite over moulting into the resulting nymphs. These results indicate that the parasitic stages infective for the vector (i.e. the sexual stages) can be produced in vitro. To our knowledge, this is the first report of artificial feeding of I. ricinus via membrane as well as in vitro transmission of B. divergens to its vector. The opportunities offered by the use of such a transmission model of a pathogen by I. ricinus are discussed.


Subject(s)
Arachnid Vectors/parasitology , Babesiosis/parasitology , Babesiosis/transmission , DNA, Protozoan/isolation & purification , Ixodes/parasitology , Animals , Babesia/growth & development , Disease Transmission, Infectious , Female , Gerbillinae/parasitology , Humans , Infectious Disease Transmission, Vertical , Male
19.
Res Vet Sci ; 80(3): 299-307, 2006 Jun.
Article in English | MEDLINE | ID: mdl-16143354

ABSTRACT

Humoral and cellular immune responses to Fasciola gigantica experimental infection in buffaloes were studied. The results showed that 33.4+/-9.1% of the infection dose was recovered as adult flukes from infected animals at necropsy. Significant differences of weight gain between infected and non-infected buffaloes was observed at 4 MPI (months post-infection). Anti F. gigantica excretory-secretory products (FgESP)-IgG levels increased significantly from 3 WPI (weeks post-infection) and displayed a peak at 13 WPI. Western blot indicated that in FgESP six major bands of 11.5, 19.0, 23.4, 29.8, 47.5 and 53.2kDa were recognized by F. gigantica-infected buffaloes sera after 0 WPI. Eosinophil numbers increased significantly from 3 WPI in F. gigantica-infected buffaloes and displayed a peak at 8 WPI. Peripheral blood mononuclear cells (PBMC) proliferation induced by FgESP increased from 2 WPI with a peak at 5 WPI. IFNgamma secretion by FgESP-stimulated PBMC appeared early from 1 WPI with three peaks at 2, 5 and 8 WPI, respectively. IL-10 production was observed from 2 WPI with two peaks at 4 and 9 WPI, respectively. Our results suggested that buffaloes were highly susceptible to F. gigantica infection, and this susceptibility could be associated with the late and weak cellular immune response in the early phase of infection and the Th0-like response throughout the infection.


Subject(s)
Buffaloes/immunology , Buffaloes/parasitology , Fasciola/immunology , Fascioliasis/immunology , Fascioliasis/veterinary , Animals , Antibodies, Helminth/blood , Antibody Formation/immunology , Antigens, Helminth/immunology , Blotting, Western/veterinary , Buffaloes/blood , Cell Proliferation , Enzyme-Linked Immunosorbent Assay/veterinary , Fascioliasis/blood , Fascioliasis/parasitology , Immunity, Cellular/immunology , Interferon-gamma/immunology , Interleukin-10/immunology , Kinetics , Leukocyte Count/veterinary , Leukocytes, Mononuclear/cytology , Leukocytes, Mononuclear/immunology , Liver/parasitology , Statistics, Nonparametric , Weight Gain
20.
Exp Parasitol ; 111(3): 154-9, 2005 Nov.
Article in English | MEDLINE | ID: mdl-16126202

ABSTRACT

Cellular responses to Fasciola gigantica and to Fasciola hepatica infection in sheep were compared. Eosinophil numbers increased more quickly and strongly in F. gigantica-infected sheep than in F. hepatica-infected sheep. In both groups, peripheral blood mononuclear cell (PBMC) proliferation in response to the parasitic excretory-secretory products (ESP) showed similar kinetics. Interferon-gamma (IFN-gamma) production by ESP-stimulated PBMC was early and showed similar kinetics in both groups. Interleukin-10 (IL-10) production by FhESP-stimulated PBMC was very high throughout infection even at 0 weeks post-infection (WPI) in F. hepatica-infected sheep, while in F. gigantica-infected sheep, IL-10 production by FgESP-stimulated PBMC increased between 1 and 4 WPI. IL-10 production in F. gigantica-infected sheep was significantly lower than in F. hepatica-infected sheep during infection. The lower susceptibility to F. gigantica infection in sheep could be explained by the more intense cellular response induced by the parasite and the weaker capacity of F. gigantica to evade the immune response.


Subject(s)
Fasciola hepatica/immunology , Fasciola/immunology , Fascioliasis/veterinary , Sheep Diseases/immunology , Animals , Antigens, Helminth/immunology , Cell Proliferation , Eosinophils/cytology , Eosinophils/immunology , Fascioliasis/immunology , Fascioliasis/parasitology , Helminth Proteins/immunology , Immunity, Cellular , Interferon-gamma/biosynthesis , Interleukin-10/biosynthesis , Kinetics , Leukocyte Count/veterinary , Leukocytes, Mononuclear/cytology , Leukocytes, Mononuclear/immunology , Male , Random Allocation , Sheep , Sheep Diseases/parasitology
SELECTION OF CITATIONS
SEARCH DETAIL
...