A longitudinal study of the diversity and dynamics of Mycoplasma hyopneumoniae infections in pig herds     

Vranckx K  Maes D  Sacristán Rdel P  Pasmans F  Haesebrouck F 《Veterinary microbiology》2012,156(3-4):315-321

A longitudinal study was carried out to investigate the diversity and persistence of Mycoplasma hyopneumoniae (M. hyopneumoniae) strains in four infected pig herds. In each herd, 20 pigs were randomly selected and blood and/or bronchoalveolar lavage (BAL) fluid was collected at 6, 10, 14 and 26 weeks of age. In the BAL fluid, quantitative PCR and MLVA (multiple-locus variable number of tandem repeats (VNTR) analysis) testing were performed for detection and typing of M. hyopneumoniae strains, respectively. At 26 weeks of age, the prevalence and severity of lung lesions were recorded at slaughter (minimum 50 pigs belonging to the same batch as the investigated pigs). The percentage of pigs testing positive on qPCR increased from 35% at 6 weeks to 96% at 26 weeks of age. With MLVA testing, positive pigs were found from 14 weeks onwards. Within each herd, only one distinct strain was detected, although clonal variants were identified in two herds. In three of the herds, the strain remained present until slaughter age. The percentage of pigs with Mycoplasma-like lesions ranged from 38% to 98%, and the average pneumonia score ranged from 1.7 to 11.9, respectively. The present field study documented that within a herd, mainly one distinct M. hyopneumoniae strain was present that persisted in the same animals for at least 12 weeks. This implies that the immune response of the animals following infection is not able to rapidly clear the infection from the respiratory tract.  相似文献   

Fetal protection against bovine viral diarrhoea type 1 virus infection after one administration of a live-attenuated vaccine     

Meyer G  Deplanche M  Roux D  Moulignie M  Picard-Hagen N  Lyazrhi F  Raboisson D  Mathevet P  Schelcher F 《Veterinary journal (London, England : 1997)》2012,192(2):242-245

A modified-live vaccine has been shown previously to prevent fetal infection with bovine viral diarrhoea virus (BVDV)-2 and, to some extent BVDV-1, when used in association with an inactivated vaccine in a two-step vaccination protocol. In this challenge study, the modified-live vaccine used alone was able to protect 13 heifers between 49 and 96 days of gestation at challenge from leucopenia and virus replication and, for a 4-month period, to prevent fetal infection. The efficacy of the BVDV-1f 22146/Han81 challenge was demonstrated by virus isolation from the fetuses of all nine non-vaccinated, control heifers. However, the small number of heifers tested meant that the vaccination failure rate could be as high as 10% in the field.  相似文献   

有关猪肺炎支原体感染诊断方法和流行病学的最新观点   总被引：1，自引：0，他引：1  

Marina Sibila  Maria Pieters  Thomas Molitor  Dnminiek Maes  沈权 《国外畜牧学(猪与禽)》2009,29(3)

猪肺炎支原体是猪地方性肺炎(Enzootic Pneumonia,EP)的主要病原体,本病是一种主要影响肥育猪的慢性呼吸道疾病.尽管人们在控制猪肺炎支原体感染及其带来的不利影响上花费了大量的精力,但是猪地方性肺炎仍继续给全球养猪生产造成重大的经济损失.猪肺炎支原体通常是通过引进亚临床型感染的动物而侵入猪群的,或通过短距离的空气传播发生感染,但后一种情况较少.一旦侵入猪群,猪肺炎支原体可通过与受感染的母猪直接接触而将病原体传给后代或在同圈猪只之间进行传播.用于诊断猪肺炎支原体感染的"黄金标准"技术--细菌学培养非常费劲,通常很少使用.酶联免疫吸附试验和聚合酶链式反应检测方法以及以屠宰场监测或田间剖解为形式的死后检查,是用于调查猪肺炎支原体是否参与了猪呼吸道疾病的最常用技术.这些技术已被用来监测受猪地方性肺炎影响的猪群猪肺炎支原体的临床型和亚临床型感染猪群、免疫猪群或非免疫猪群以及处于不同的生产条件和管理条件下的猪群的发生情况.猪场水平上的猪地方性肺炎临床过程差异以及猪肺炎支原体疫苗接种效果的差异表明,猪肺炎支原体的不同田间分离株的传播和毒力特性存在差异.本文综述了猪肺炎支原体感染的流行病学最新知识,包括其传播、感染和血清转化动力学,并且还比较了用来监测猪地方性肺炎的各种流行病学方法.  相似文献   

Distribution of Trace Elements in Sediments and Biota of Songkhla Lake, Southern Thailand     

Siriporn Pradit  Gullaya Wattayakorn  Saowapa Angsupanich  Willy Baeyens  Martine Leermakers 《Water, air, and soil pollution》2010,206(1-4):155-174

The concentrations of Co, Ni, Cu, Zn, Cd, Pb, As, Fe, Mn, and Al were determined in sediments and biota of Songkhla Lake, a shallow coastal lagoon located in southern Thailand. In June 2006, surface sediments were sampled in 44 stations in the three sections of the lake (inner-, middle-, and outer sections). Sediment cores were also sampled in 13 stations in three cross-sections of the lake. In surface sediments, trace and major elements, organic matter, sediment grain size analysis, and sulfides were determined, and in the sediment cores, redox profiles were made. Soil samples were also collected at garbage dumping sites in the vicinity of the lake. In addition, the metal accumulation in two catfish species (Arius maculatus and Osteogeneiosus militaris) and the crustacean (Apseudes sapensis) was also investigated. Trace element concentrations in sediments of Songkhla Lake show that, especially the Outer section of the lake, in particular the sediments at the mouths of the Phawong, U-Taphao, and Samrong Canals are significantly enriched with trace elements due to municipal, agricultural, and industrial discharges entering the lake through the canals. Aluminum-normalized enrichment factors throughout the lake vary from 0.4 to 1.7 for Ni, 0.3 to 3.3 for Cu, 0.2 to 7 for Zn, 0.1 to 14 for As, 1 to 24 for Cd, 0.7 to 6.8 for Pb, and 0.1 to 7.8 for Mn. Correlations between the elements and sediment characteristics show that Cu, Zn, Cd, and Pb are essentially associated with the sulfide fraction; that Ni and Co are predominantly bound to the clay minerals and iron oxy-hydroxides, and that As is principally bound to iron oxy-hydroxides. The accumulation of trace elements between muscle tissue and liver and eggs of A. maculatus and O. militaris is element-specific, but concentrations of trace elements in fish muscle tissue are well within the limits for human consumption.  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   

Efficacy of transsphenoidal hypophysectomy in treatment of dogs with pituitary-dependent hyperadrenocorticism     

Hanson JM  van 't HM  Voorhout G  Teske E  Kooistra HS  Meij BP 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2005,19(5):687-694

The long-term survival, disease-free fractions, and the complications of hypophysectomy in 150 dogs with pituitary-dependent hyperadrenocorticism (PDH) were examined in a prospective study. Long-term survival and disease-free fractions in relation to pituitary size were analyzed by the Kaplan-Meijer estimate procedure. The 1-, 2-, 3-, and 4-year estimated survival rates were 84% (95% confidence interval [CI], 76-89%), 76% (67-83%), 72% (62-79%), and 68% (55-77%), respectively. Treatment failures included procedure-related mortalities (12 dogs) and incomplete hypophysectomies (9 dogs). The 1-, 2-, 3-, and 4-year estimated relapse-free fractions were 88% (CI: 80-93%), 75% (64-83%), 66% (54-76%), and 58% (45-70%), respectively. Postoperative reduction of tear production (58 eyes in 47 dogs) was often reversible but remained low until death in 11 eyes of 10 dogs. Central diabetes insipidus (CDI) occurred more frequently (62%) in dogs with enlarged pituitaries than in dogs with nonenlarged pituitaries (44%). Survival and disease-free fractions after hypophysectomy were markedly higher in dogs with nonenlarged pituitaries than in dogs with enlarged pituitaries. Transsphenoidal hypophysectomy is an effective treatment for PDH in dogs. The survival and disease-free fractions after hypophysectomy decrease and the incidence of CDI increases with increasing pituitary size. Therefore, early diagnosis of PDH is important and transsphenoidal hypophysectomy is expected to have the best outcome when used as primary treatment for dogs with nonenlarged or moderately enlarged pituitaries.  相似文献   

Discrepancies between the isolation of Salmonella from mesenteric lymph nodes and the results of serological screening in slaughter pigs     

Nollet N  Maes D  Duchateau L  Hautekiet V  Houf K  Van Hoof J  De Zuttera L  De Kruif A  Geers R 《Veterinary research》2005,36(4):545-555

Most Salmonella control programmes are based on serological testing in the slaughterhouse. However, from a point of view of carcass contamination, it is rather the presence of Salmonella spp. in the animal at the time of slaughter that is important. The aim of this cross-sectional study was to investigate the possible discrepancies between the isolation of Salmonella spp. in the mesenteric lymph nodes and the results of serological screening. In total, 1821 fattening pigs originating from 60 Belgian farrow-to-finish herds were sampled in the slaughterhouse. The serum samples were analysed using an indirect mix-ELISA for the presence of Salmonella antibodies and evaluated at 3 cut-off values namely 10, 20, and 40% Optical Density (OD). All mesenteric lymph node samples were submitted to qualitative Salmonella isolation and a representative number of isolates was serotyped. From each herd, 30 animals were screened both serologically and bacteriologically and the herd was considered as positive when at least one sample was positive. At the herd level, 83.6% (cut-off OD 40%) to 100.0% (cut-off OD 10%) of the herds from which Salmonella had been isolated were evaluated as seropositive. At the individual level, only 34.5% (cut-off OD 40%) to 82.8% (cut-off OD 10%) of the animals from which Salmonella had been isolated were seropositive. Overall, a weak agreement was found between bacteriology and serology for Salmonella diagnosis. If pig herds are categorised using serological tests in the slaughterhouse, one should be aware of the fact that slaughter pigs can still harbour Salmonella spp. in the mesenteric lymph nodes, without being detected in serological tests. The cut-off value used to evaluate a sample as serologically positive and the number of samples per herd are of major importance to classify herds correctly in order to protect human health.  相似文献   

Human and bovine respiratory syncytial virus vaccine research and development     

Meyer G  Deplanche M  Schelcher F 《Comparative immunology, microbiology and infectious diseases》2008,31(2-3):191-225

Human (HRSV) and bovine (BRSV) respiratory syncytial viruses (RSV) are two closely related viruses, which are the most important causative agents of respiratory tract infections of young children and calves, respectively. BRSV vaccines have been available for nearly 2 decades. They probably have reduced the prevalence of RSV infection but their efficacy needs improvement. In contrast, despite decades of research, there is no currently licensed vaccine for the prevention of HRSV disease. Development of a HRSV vaccine for infants has been hindered by the lack of a relevant animal model that develops disease, the need to immunize immunologically immature young infants, the difficulty for live vaccines to find the right balance between attenuation and immunogenicity, and the risk of vaccine-associated disease. During the past 15 years, intensive research into a HRSV vaccine has yielded vaccine candidates, which have been evaluated in animal models and, for some of them, in clinical trials in humans. Recent formulations have focused on subunit vaccines with specific CD4+ Th-1 immune response-activating adjuvants and on genetically engineered live attenuated vaccines. It is likely that different HRSV vaccines and/or combinations of vaccines used sequentially will be needed for the various populations at risk. This review discusses the recent advances in RSV vaccine development.  相似文献   

A survey on biosecurity and management practices in Belgian pig herds     

Ribbens S  Dewulf J  Koenen F  Mintiens K  De Sadeleer L  de Kruif A  Maes D 《Preventive veterinary medicine》2008,83(3-4):228-241

We surveyed Belgian pig herds to describe their biosecurity status and management practices. Our written questionnaire was sent to a stratified random sample of 609 pig farms. We achieved a 71.6% response, and 421/609 farmers (69.1%) returned questionnaires suitable for analysis. We used multiple-correspondence analysis followed by a two-step clustering procedure. Herd size, herd type and occupation (commercial or hobby herd) were used to describe different groups. We differentiated four biosecurity groups, which we interpreted as indicating low- to high-biosecurity status. Although we felt that most farms had acceptable biosecurity, few used measures such as showering (2.1%) and quarantine periods for people entering the premises (7.1%). We also found three management-practices clusters, although their interpretation was not straightforward. Despite the industrialised character of pig production in Belgium, 9.4% of pig herds were small, hobby herds that reported different biosecurity and management characteristics (such as the equipping pigs on pasture and feeding kitchen waste).  相似文献   

Clinicopathologic features of a systemic coronavirus-associated disease resembling feline infectious peritonitis in the domestic ferret (Mustela putorius)     

Garner MM  Ramsell K  Morera N  Juan-Sallés C  Jiménez J  Ardiaca M  Montesinos A  Teifke JP  Löhr CV  Evermann JF  Baszler TV  Nordhausen RW  Wise AG  Maes RK  Kiupel M 《Veterinary pathology》2008,45(2):236-246

From 2002 to 2007, 23 ferrets from Europe and the United States were diagnosed with systemic pyogranulomatous inflammation resembling feline infectious peritonitis (FIP). The average age at the time of diagnosis was 11 months. The disease was progressive in all cases, and average duration of clinical illness was 67 days. Common clinical findings were anorexia, weight loss, diarrhea, and large, palpable intra-abdominal masses; less frequent findings included hind limb paresis, central nervous system signs, vomiting, and dyspnea. Frequent hematologic findings were mild anemia, thrombocytopenia, and hypergammaglobulinemia. Grossly, whitish nodules were found in numerous tissues, most frequently the mesenteric adipose tissue and lymph nodes, visceral peritoneum, liver, kidneys, spleen, and lungs. One ferret had a serous abdominal effusion. Microscopically, pyogranulomatous inflammation involved especially the visceral peritoneum, mesenteric adipose tissue, liver, lungs, kidneys, lymph nodes, spleen, pancreas, adrenal glands, and/or blood vessels. Immunohistochemically, all cases were positive for coronavirus antigen using monoclonal antibody FIPV3-70. Electron microscopic examination of inflammatory lesions identified particles with coronavirus morphology in the cytoplasm of macrophages. Partial sequencing of the coronavirus spike gene obtained from frozen tissue indicates that the virus is related to ferret enteric coronavirus.  相似文献