A retrospective study of 29 cases of otitis media/interna in dairy calves     

Véronique Bernier Gosselin  David Francoz  Marie Babkine  André Desrochers  Sylvain Nichols  Elizabeth Doré  Christian Bédard  Joane Parent  Julie-Hélène Fairbrother  Gilles Fecteau 《The Canadian veterinary journal. La revue veterinaire canadienne》2012,53(9):957-962

Epidemiological data, clinical findings, laboratory data, medical imaging, and outcomes were reviewed in 29 dairy calves with otitis media/interna. Age at admission ranged from 1 to 24 wk. The majority of calves were referred during winter. Clinical signs included drooping ear, ptosis, head tilt, abnormal nystagmus, strabismus, dysphagia, regurgitation, stiff neck, opisthotonos, facial hyperesthesia, and purulent aural discharge. Intranasal endoscopic examination of 5 animals revealed nasopharyngeal collapse in 4. Cerebrospinal fluid (CSF) was abnormal in all of 7 cases. Mycoplasma bovis was cultured from all but 1 case with external ear or tympanic bullae samples (n = 12), and Mycoplasma arginini was cultured from the remaining ear sample. Radiographs of the tympanic bullae were performed in 24 calves, tomodensitometry (CT) in 3 calves and ultrasound in 4 calves. According to medical imaging techniques or necropsy, 69% of the cases were classified as chronic. Mean duration of treatment was 23.3 d. The rate of clinical recovery was 75%.  相似文献   

Hydraulic efficiency and safety of vascular and non-vascular components in Pinus pinaster leaves     

K Charra-Vaskou  E Badel  R Burlett  H Cochard  S Delzon  S Mayr 《Tree physiology》2012,32(9):1161-1170

Leaves, the distal section of the soil-plant-atmosphere continuum, exhibit the lowest water potentials in a plant. In contrast to angiosperm leaves, knowledge of the hydraulic architecture of conifer needles is scant. We investigated the hydraulic efficiency and safety of Pinus pinaster needles, comparing different techniques. The xylem hydraulic conductivity (k(s)) and embolism vulnerability (P(50)) of both needle and stem were measured using the cavitron technique. The conductance and vulnerability of whole needles were measured via rehydration kinetics, and Cryo-SEM and 3D X-ray microtomographic observations were used as reference tools to validate physical measurements. The needle xylem of P. pinaster had lower hydraulic efficiency (k(s)?=?2.0?×?10(-4) m(2) MPa(-1) s(-1)) and safety (P(50)?=?-?1.5 MPa) than stem xylem (k(s)?=?7.7?×?10(-4) m(2) MPa(-1) s(-1); P(50)?=?-?3.6 to?-?3.2 MPa). P(50) of whole needles (both extra-vascular and vascular pathways) was?-?0.5 MPa, suggesting that non-vascular tissues were more vulnerable than the xylem. During dehydration to?-?3.5 MPa, collapse and embolism in xylem tracheids, and gap formation in surrounding tissues were observed. However, a discrepancy in hydraulic and acoustic results appeared compared with visualizations, arguing for greater caution with these techniques when applied to needles. Our results indicate that the most distal parts of the water transport pathway are limiting for hydraulics of P. pinaster. Needle tissues exhibit a low hydraulic efficiency and low hydraulic safety, but may also act to buffer short-term water deficits, thus preventing xylem embolism.  相似文献   

Antibiotic resistance in Escherichia coli and Enterococcus spp. isolates from commercial broiler chickens receiving growth-promoting doses of bacitracin or virginiamycin          下载免费PDF全文

Alexandre Thibodeau  Sylvain Quessy  Evelyne Guvremont  Alain Houde  Edward Topp  Moussa Sory Diarra    Ann Letellier 《Canadian journal of veterinary research》2008,72(2):129-136

Antibacterial agents such as zinc bacitracin (ZB) and virginiamycin (VG) are used as growth promoting agents (GP) in broiler chicken production. The objective of this study was to evaluate the effect of the use of ZB and VG on the emergence of antibacterial resistance in a commercial broiler chicken farm. Three trials were conducted using 3 different diets: one without antibacterial agents, one containing VG, and one with ZB. Escherichia coli and Enterococcus spp. strains were isolated and tested for their susceptibility to various antibacterial agents. The occurrence of the resistance genes vatD, ermB, and bcrR in Enterococcus spp. isolates was determined by polymerase chain reaction (PCR). Comparative quantification of vatD and bcrR genes in total deoxyribonucleic acid (DNA) extracts from litter was done by SYBR Green Real-Time PCR (QPCR). Escherichia coli and Enterococcus spp. isolates from diet groups had different levels of resistance to various antibacterial agents over time. These GPs did not select for specific antibacterial agent resistance (AAR) in Enterococcus spp. The use of GPs seemed to lower the percentage of E. coli isolates resistant to some antibacterial agents. The presence of the bcrR gene could not explain all resistant phenotypes to ZB. Genes other than vatD and ermB might be involved in the resistance to VG in Enterococcus spp. Use of GPs was not associated with presence of the bcrR gene in DNA extracts from litter, but use of VG was associated with vatD presence.  相似文献   

Evidence of cross-contamination by Campylobacter spp. of broiler carcasses using genetic characterization of isolates          下载免费PDF全文

Valrie Normand  Martine Boulianne    Sylvain Quessy 《Canadian journal of veterinary research》2008,72(5):396-402

Campylobacter is recognized as one of the leading cause of gastroenteritis worldwide, and is frequently isolated from the small intestines and ceca microflora of chickens. Twenty-one out of 81 Campylobacter-positive poultry flocks were selected to evaluate the genetic diversity of Campylobacter isolates and to study the distribution of genotypes among flocks. Campylobacter isolates recovered from chicken carcasses and ceca were analyzed by pulsed-field gel electrophoresis (PFGE). Little diversity was found among Campylobacter strains isolated from a given carcass, with a maximum of 2 different genotypes being present. However, at flock level, as many as 4 different profiles were observed. Typing of strains showed that most strains isolated from ceca were similar to those isolated from corresponding broiler carcasses. A total of 39 different macrorestriction profiles were observed, with evidence of Campylobacter cross-contamination among broiler flocks in Quebec slaughterhouses. Surprisingly, some flocks shared related genotypes both with and without sharing similar rearing practices. Existence of such cross-contamination must be considered to in developing strategies to control Campylobacter in chickens, and to avoid bacteria contamination of noncolonized flocks. Further typing studies of Campylobacter found in hatcheries, farm environment, and crates or trucks in Quebec might be helpful in elucidating the kinetics of broiler chicken Campylobacter contamination.  相似文献   

Cellular pathogenesis in prion diseases     

Crozet C  Beranger F  Lehmann S 《Veterinary research》2008,39(4):44

Prion diseases are characterised by neuronal loss, vacuolation (spongiosis), reactive astrocytosis, microgliosis and in most cases by the accumulation in the central nervous system of the abnormal prion protein, named PrP(Sc). In this review on the "cellular pathogenesis in prion diseases", we have chosen to highlight the main mechanisms underlying the impact of PrP(C)/PrP(Sc) on neurons: the neuronal dysfunction, the neuronal cell death and its relation with PrP(Sc) accumulation, as well as the role of PrP(Sc) in the microglial and astrocytic reaction.  相似文献   

禽产品安全控制研究进展     

Martine  Boulianne  Ann  Letellier  Sylvain  Quessy  陈蓉 《中国家禽》2008,30(23)

在食品安全方面,最重要的发现之一是冷链系统在食品运输中的发展。从那以后,HACCP的采用已经在食品生产业中成为另一项改革,而分子生物学的最新进展使得快速微生物学方法的发展和运用相对于传统的方法来说是一种改革。公众在与食品中细菌传播有关的风险因子方面的知识已得到提高,但对弯曲杆菌的了解仍然很少。在这种情况下,本文将讨论一些细菌诊断工具,细菌收获前后的控制措施和收获后处理方法的优化。  相似文献   

Shedding light on the migratory patterns of the Amazonian goliath catfish,Brachyplatystoma platynemum,using otolith 87Sr/86Sr analyses     

Marília Hauser  Carolina R.C. Doria  Roberto V. Santos  Aurea García‐Vasquez  Marc Pouilly  Christophe Pcheyran  Emmanuel Ponzevera  Gislene Torrente‐Vilara  Sylvain Brail  Jacques Panfili  Audrey Darnaude  Jean‐Franois Renno  Carmen García‐Dvila  Jesus Nuez  Franck Ferraton  Gladys Vargas  Fabrice Duponchelle 《水产资源保护:海洋与淡水生态系统》2019,29(3):397-408

Shoot‐produced,light‐dependent factors are partially involved in the expression of the arbuscular mycorrhizal (AM) status of AM host and non‐host plants     

Horst Vierheilig  Berta Bago  Sylvain Lerat  Yves Pich 《植物养料与土壤学杂志》2002,165(1):21-25

Arbuscular mycorrhizal (AM) colonization and hyphal attachment to the roots of a host plant, bean, and a non‐host plant, lupin, were compared when grown either with light or in the dark with the AM fungus Glomus mosseae. When grown with light, bean roots were heavily colonized whereas lupin roots showed no signs of colonization, no formation of appressoria and only scarce hyphal attachment to the roots. In contrast to roots of plants grown with light, to living roots of beans and lupins grown in the dark many hyphae were attached and appressoria were formed. The role of shoot produced, light‐dependent factors in the expression of the AM mycotrophic status of AM host and non‐host plants is discussed.<?show $6#>  相似文献   

Predicting load path and tensile forces during cable yarding operations on steep terrain     

Sylvain Dupire  Franck Bourrier  Frédéric Berger 《Journal of Forest Research》2016,21(1):1-14

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DNA Quantity and Quality in Remnants of Traffic-Killed Specimens of an Endangered Longhorn Beetle: A Comparison of Different Methods     

Hans-Peter Rusterholz  Sylvain Ursenbacher  Armin Coray  Urs Weibel  Bruno Baur 《Journal of insect science (Online)》2015,15(1)

The sampling of living insects should be avoided in highly endangered species when the sampling would further increase the risk of population extinction. Nonlethal sampling (wing clips or leg removals) can be an alternative to obtain DNA of individuals for population genetic studies. However, nonlethal sampling may not be possible for all insect species. We examined whether remnants of traffic-killed specimens of the endangered and protected flighless longhorn beetle Iberodorcadion fuliginator (L., 1758) can be used as a resource for population genetic analyses. Using insect fragments of traffic-killed specimens collected over 15 yr, we determined the most efficient DNA extraction method in relation to the state of the specimens (crushed, fragment, or intact), preservation (dried, airtight, or in ethanol), storage duration, and weight of the sample by assessing the quantity and quality of genomic DNA. A modified cetyltrimethyl ammonium bromide method provided the highest recovery rate of genomic DNA and the largest yield and highest quality of DNA. We further used traffic-killed specimens to evaluate two DNA amplification techniques (quantitative polymerase chain reaction [qPCR] and microsatellites). Both qPCR and microsatellites revealed successful DNA amplification in all degraded specimens or beetle fragments examined. However, relative qPCR concentration and peak height of microsatellites were affected by the state of specimen and storage duration but not by specimen weight. Our investigation demonstrates that degraded remnants of traffic-killed beetle specimens can serve as a source of high-quality genomic DNA, which allows to address conservation genetic issues.  相似文献