New strategy for the survey of Toxoplasma gondii in meat for human consumption     

Villena I  Durand B  Aubert D  Blaga R  Geers R  Thomas M  Perret C  Alliot A  Escotte-Binet S  Thébault A  Boireau P  Halos L 《Veterinary parasitology》2012,183(3-4):203-208

Monitoring of Toxoplasma infection in animals destined for human consumption is a great challenge for human toxoplasmosis prevention. This study aimed to compare results obtained from a naturally infected population of sheep using different tests and targeting an original matrix: meat samples and muscle fluids collected at the slaughterhouse. A commercial ELISA test was performed on diaphragm fluids from 419 ovine carcasses collected at the slaughterhouse. A MAT (modified agglutination test) was performed on heart fluids obtained from the same animals. In addition, all hearts were bioassayed in mice. Serological test agreement, the relative sensitivity of ELISA MAT and mouse bioassay as well as a correlation between titres and parasite isolation probability were statistically evaluated. The overall agreement (kappa coefficient=0.64) of ELISA on diaphragm fluids and MAT on heart fluids is substantial and subsequently both tests can be used for epidemiological studies. Relative sensitivity was higher for MAT performed on cardiac fluids (90%) than ELISA on diaphragm fluid (61%). For both serological tests, relative sensitivity is lower in lambs younger than 12 months. Relative sensitivity of mouse inoculation was 42%. A significant correlation was obtained between increasing MAT titres and probability to isolate live parasite from the heart. When the fluid titre was higher than 1:16, parasites were isolated in 65% of cases. When it was lower, isolation failed in 95% of the cases. According to our results, cardiac fluids appear to be a relevant matrix for toxoplasmosis survey in meat.  相似文献   

Evidence-Based Practice? An Evolution Is Necessary for Bovine Practitioners,Teachers, and Researchers     

Jean-Michel Vandeweerd  Pascal Gustin  Sébastien Buczinski 《Veterinary Clinics of North America: Food Animal Practice》2012

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A comparison of in vitro relaxant responses to ipratropium bromide, β-adrenoceptor agonists and theophylline in feline bronchial smooth muscle     

Leemans J  Kirschvink N  Gustin P 《Veterinary journal (London, England : 1997)》2012,193(1):228-233

This study compares the potency and efficacy of different relaxant drugs including anticholinergic, β-adrenergic and methylxanthine agents on acetylcholine-contracted feline bronchi, and investigates the influence of the initial muscarinic-induced tone on bronchodilator response. Feline bronchi were removed from euthanased client-owned cats and were contracted with acetylcholine to cause either 40% or 80% of the acetylcholine maximal contraction. The efficacy and potency of bronchodilating drugs were obtained from cumulative dose-response curves with efficacy (E(max)) as the maximal relaxant response and potency (-logEC(50)) as the logarithm of the concentration of drug inducing 50% of maximal relaxation. Under low contractile tone (40%), all bronchodilators relaxed feline bronchi in a concentration-dependent manner with the following rank order of potency: formoterol>ipratropium bromide>fenoterol>isoprenaline>salbutamol≥salmeterol>theophylline. E(max) values ranged from 80% to 100% depending on the tested drug. Constriction of feline bronchi with high-dose acetylcholine (80%) caused a rightward and downward shift of the β(2)-mimetic dose-response curves. Significant decreases in -logEC(50) and E(max) values were reported for salbutamol, formoterol and salmeterol. This study provides evidence that existing classes of bronchodilators produce effective relaxation of acetylcholine-contracted feline bronchi and that airway responsiveness to β(2)-stimulants is dependent on the magnitude of the initial muscarinic-induced tone. The clinical relevance of these in vitro findings has yet to be explored in clinical trials.  相似文献   

Salmeterol or doxycycline do not inhibit acute bronchospasm and airway inflammation in cats with experimentally-induced asthma     

Leemans J  Kirschvink N  Bernaerts F  Clercx C  Snaps F  Billen F  Gustin P 《Veterinary journal (London, England : 1997)》2012,192(1):49-56

The objective of this study was to determine if inhaled salmeterol, a long-acting β(2)-adrenergic agonist, and oral doxycycline, a tetracycline antibiotic displaying matrix metalloproteinase (MMP) inhibitory activity, reduce airway inflammation and obstruction in cats with experimentally-induced asthma. Eight Ascaris suum (AS)-sensitised cats were enrolled in a prospective study in which they underwent four AS-challenges at 1 month intervals. The challenged animals were given no treatment or were treated on 4 consecutive days with either: (1) oral prednisolone (1mg/kg twice daily), (2) inhaled salmeterol (50 μg twice daily), or (3) oral doxycycline (5mg/kg twice daily), according to a randomised cross-over design. Inhibition of allergen-induced early (EAR) and late (LAR) asthmatic reactions were assessed by barometric whole-body plethysmography. Cytology and measurement of MMP-2 and -9 activities were carried out on bronchoalveolar lavage fluid (BALF). Although none of the treatments prevented the EAR, prednisolone treatment inhibited the LAR. Relative to untreated cats, the eosinophil percentage and MMP-2 activity in BALF were significantly reduced following prednisolone treatment (P<0.05). Short-term therapy with either salmeterol or doxycycline had no effect on the EAR or LAR or on airway inflammation. Given the chronic nature of this disease in cats, long-term therapy may be required to produce more favourable functional and clinical outcomes.  相似文献   

Effect of short-term oral and inhaled corticosteroids on airway inflammation and responsiveness in a feline acute asthma model     

Leemans J  Kirschvink N  Clercx C  Snaps F  Gustin P 《Veterinary journal (London, England : 1997)》2012,192(1):41-48

The objective of this study was to investigate whether high-dose inhaled fluticasone propionate (FP), alone or in combination with salmeterol (SAL), is as effective as oral prednisolone in reducing airway inflammation and obstruction in cats with experimentally-induced acute asthma. Six cats sensitised to Ascaris suum (AS) were enrolled in a prospective controlled therapeutic trial and underwent four aerosol challenges, at 1-month intervals with AS allergen. The allergen - stimulated animals received four consecutive days treatment with either oral prednisolone at 1mg/kg twice daily, 500 μg of FP inhaled twice daily, or a combination of FP/SAL at 500 μg/50 μg inhaled twice daily, respectively, according to a randomised cross-over design. Treatment-related changes in lung function, airway responsiveness (AR) and bronchoalveolar lavage fluid (BALF) cytology were assessed. Barometric whole-body plethysmography (BWBP) was used for the assessment of respiratory variables and AR. No significant differences in respiratory rate or Penh (an estimate of airflow limitation measured by BWBP) were detected among treatment groups. Allergen-induced airway hyper-responsiveness was significantly inhibited by all three steroid treatments (P<0.05). The mean BALF eosinophil percentage (±SEM) was lower after oral and inhaled corticosteroid treatment and these changes were significant for groups receiving prednisolone and the FP/SAL combination. Findings suggest high-dose FP, particularly in combination with SAL, is effective in ameliorating airway inflammation and hyper-responsiveness in this model of acute feline asthma, and highlight the potential use of these drugs in cats experiencing acute exacerbations of the naturally occurring disease.  相似文献   

In vitro follicle culture shows that progestagens are the maturation-inducing hormones (MIH) and possible regulators of the ovulation-mediating hormone PGE2 in female Eurasian perch Perca fluviatilis     

El Mohajer  Leila  Bulteau  Rose  Chevalier  Céline  Selmi  Sirine  Fontaine  Pascal  Milla  Sylvain 《Fish physiology and biochemistry》2021,47(4):881-894

In European aquaculture, Eurasian perch, Perca fluviatilis L., is perceived as one of the most highly valuable freshwater fish species and a strong candidate for the development of freshwater aquaculture. In the pursuit of improving the quality of reproduction in this domesticated species, investigating the hormones mediating the final oocyte maturation (FOM) is therefore indispensable. But, the exact nature of the maturation-inducing hormone (MIH) in Eurasian perch is unknown. To further validate the existence of a maturation-inducing activity behind potential hormonal candidates in this species, we in vitro tested a group of nine hormones: cortisol (Co), 11-deoxycortisol (11-D), corticosterone (coS), 11-deoxycorticosterone (DOC), 17α,20βdihydroxy-4-pregnen-3-one (DHP) and 17α,20β,21 trihydroxy-4-pregnen-3-one (THP), prostaglandin E₂ (PGE2), estradiol-17β (E2) and testosterone (T), in their ability to trigger FOM advancement and the production of sex steroids potentially involved in FOM. Using mature female perch, two in vitro experiments were conducted with oocytes at the start of the FOM. The follicles were incubated for 62 h in Cortland media with and without human chorionic gonadotropin (hCG). By the end of the incubation, only DHP and THP triggered the full advancement in FOM even at low doses with the effect of DHP being in vivo validated. However, the de novo productions of E2 and DHP were not shown to be regulated by either of the MIH candidates. Progestagens are hence more credible candidates as MIH than corticosteroids in Eurasian perch. Our in vitro study also revealed that both PGE2 and DHP are strongly associated with ovulation and that PGE2 might have slightly contributed to such DHP activity.

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Trichinella diagnostics and control: Mandatory and best practices for ensuring food safety     

Alvin A. Gajadhar  Edoardo Pozio  H. Ray Gamble  Karsten Nöckler  Charlotte Maddox-Hyttel  Lorry B. Forbes  Isabelle Vallée  Patrizia Rossi  Albert Marinculić  Pascal Boireau 《Veterinary parasitology》2009,159(3-4):197-205

Because of its role in human disease, there are increasing global requirements for reliable diagnostic and control methods for Trichinella in food animals to ensure meat safety and to facilitate trade. Consequently, there is a need for standardization of methods, programs, and best practices used in the control of Trichinella and trichinellosis. This review article describes the biology and epidemiology of Trichinella, and describes recommended test methods as well as modified and optimized procedures that are used in meat inspection programs. The use of ELISA for monitoring animals for infection in various porcine and equine pre- and post-slaughter programs, including farm or herd certification programs is also discussed. A brief review of the effectiveness of meat processing methods, such as freezing, cooking and preserving is provided. The importance of proper quality assurance and its application in all aspects of a Trichinella diagnostic system is emphasized. It includes the use of international quality standards, test validation and standardization, critical control points, laboratory accreditation, certification of analysts and proficiency testing. Also described, are the roles and locations of international and regional reference laboratories for trichinellosis where expert advice and support on research and diagnostics are available.  相似文献   

Transmission risk of human trichinellosis     

Katsuhisa Takumi  Peter Teunis  Manoj Fonville  Isabelle Vallee  Pascal Boireau  Karsten Nöckler  Joke van der Giessen 《Veterinary parasitology》2009,159(3-4):324-327

Trichinella is a food-borne parasitic zoonoses and human cases are still reported in Europe mainly due to the consumption of pig meat originating from small backyard farms. Infections originating from industrialized pig farming have not been reported for decades in Europe, due to control measures to prevent the transmission of Trichinella from wildlife by indoor housing and good management practices. Therefore, risk-based monitoring programs might replace individual carcass control in industrialized pig farming as described in EU legislation SANCO 2075/2005. Transmission of Trichinella species between wildlife and the risk that may pose to humans via consumption of contaminated pork meat has not been studied quantitatively. One pathway by which human trichinellosis can occur is the rat–pig–human route. To evaluate the transmission risk though this pathway the dose responses of rat, pig, and human were studied. Experimental T. spiralis infection was performed in rats with doses of as few as 10 parasites and the data set was analysed using a newly developed dose response model that describes larvae per gram (LPG). Experimental T. spiralis infection in pig was analysed in a similar way. Furthermore nine published outbreaks of human trichinellosis were analysed to determine the dose response in humans. The risk of human trichinellosis via the rat–pig–human transmission was simulated by the Monte Carlo method. A pair of female and male parasites representing the lowest infection pressure from the environment, led to the probability of human trichinellosis by consumption of 100 g of raw pork meat equal to 5% via the studied rat–pig–human pathway. In the absence of rodent control near the farm, a low infection pressure from wildlife presents a relatively high risk of human trichinellosis via consumption of uncooked pork meat.  相似文献   

Utilization of near infrared reflectance spectroscopy (NIRS) to quantify the impact of earthworms on soil and carbon erosion in steep slope ecosystem: A study case in Northern Vietnam     

Pascal Jouquet  Thierry Henry-des-Tureaux  Jérôme Mathieu  Thuy Doan Thu  Toan Tran Duc  Didier Orange 《CATENA》2010

This work focuses on a new approach to quantify the effects of above-ground earthworm's activity on soil erosion in steep slope ecosystems such as in Northern Vietnam. In these areas and in many others in the world, soil erosion becomes a major issue while the factors that determine it are still misunderstood. Earthworm's activity is believed to influence soil erosion rate, but we are still unable to precisely quantify their contribution to soil erosion. In this study, we used Near Infrared Reflectance Spectroscopy (NIRS) to quantify the proportion of soil aggregate in eroded soil coming from earthworm activity. This was done by generating NIRS signatures corresponding to different soil surface aggregates (above-ground soil casts produced by earthworms vs. surrounding topsoil).  相似文献   

Influence of adjuvant formulation on the induced protection of mice immunized with total soluble antigen of Trichinella spiralis   总被引：1，自引：0，他引：1  

Deville S  Pooter Ad  Aucouturier J  Lainé-Prade V  Cote M  Boireau P  Vallée I 《Veterinary parasitology》2005,132(1-2):75-80

Vaccination of pigs against the helminth nematode Trichinella could be a good alternative to prevent the risk of human infection. In order to develop an efficient and safe vaccine, the choice of the adjuvant is an important issue. In this study, two adjuvants were selected to prepare vaccines based on total soluble Trichinella spiralis muscle larvae (ML) antigen: Montanide ISA 70 water in oil emulsion and Montanide IMS nanoparticles. Aluminium hydroxide was used as a reference adjuvant. The immune response was checked by ELISA of parasite antigen specific IgG1 and IgE. Finally, protection induced in vaccinated mice was measured after a T. spiralis challenge by counting ML burdens. The results clearly showed an impact of adjuvants on the specific IgG1 and IgE antibody responses against T. spiralis. Differences were observed between the rates of protection induced according to the type of formulation, although the three adjuvants tested were able to enhance the humoral immune response. This work demonstrated the need to use an adjuvant to obtain a specific IgG1 and IgE responses directed against the total soluble extract of T. spiralis.  相似文献