Differences in phagocytosis susceptibility in Haemophilus parasuis strains     

Alexandre Olvera  Maria Ballester  Miquel Nofrar��as  Marina Sibila    Virginia Aragon 《Veterinary research》2009,40(3)

Haemophilus parasuis is a colonizer of the upper respiratory tract of healthy pigs, but virulent strains can cause a systemic infection characterized by fibrinous polyserositis, commonly known as Glässer’s disease. The variability in virulence that is observed among H. parasuis strains is not completely understood, since the virulence mechanisms of H. parasuis are largely unknown. In the course of infection, H. parasuis has to survive the host pulmonary defences, which include alveolar macrophages, to produce disease. Using strains from different clinical backgrounds, we were able to detect clear differences in susceptibility to phagocytosis. Strains isolated from the nose of healthy animals were efficiently phagocytosed by porcine alveolar macrophages (PAM), while strains isolated from systemic lesions were resistant to this interaction. Phagocytosis of susceptible strains proceeded through mechanisms independent of a specific receptor, which involved actin filaments and microtubules. In all the systemic strains tested in this study, we observed a distinct capsule after interaction with PAM, indicating a role of this surface structure in phagocytosis resistance. However, additional mechanisms of resistance to phagocytosis should be explored, since we detected different effects of microtubule inhibition among systemic strains.  相似文献   

Influence of Enterococcus faecium SF68 Probiotic on Giardiasis in Dogs     

K.W. Simpson  M. Rishniw  M. Bellosa  J. Liotta  A. Lucio  M. Baumgart  G. Czarnecki-Maulden  J. Benyacoub  D. Bowman 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2009,23(3):476-481

Background: Giardiasis is a common, potentially zoonotic disease, and dogs often harbor and shed cysts without showing clinical signs. Treatment with the probiotic Enterococcus faecium SF68 has been shown to stimulate mucosal and systemic immunity in a variety of animal models and in young dogs, and to reduce giardial cyst and antigen shedding in rodents.
Hypothesis: Adult dogs with chronic naturally acquired giardiasis will have decreased giardial fecal cyst and antigen shedding and increased innate and adaptive immunity after 6 weeks probiotic treatment with E. faecium SF68.
Animals: Twenty adult dogs.
Methods: After a 6-week dietary equilibration period, dogs were randomized to receive E. faecium SF68 or placebo for 6 weeks, and then crossed over to the alternate treatment. We measured cyst shedding, fecal giardial antigen, fecal immunoglobulin A (IgA) concentration, and circulating leukocyte phagocytic activity at multiple timepoints to determine the effect of E. faecium SF68 on giardiasis and immune responses in these dogs.
Results: No differences were observed between placebo or E. faecium SF68 treatment for giardial cyst shedding, fecal antigen shedding, fecal IgA concentration, or leukocyte phagocytic activity.
Conclusions: Short-term treatment with E. faecium SF68 of dogs with chronic naturally acquired subclinical giardiasis fails to affect giardial cyst shedding or antigen content and does not alter innate or adaptive immune responses.  相似文献   

复方中草药对仿刺参免疫力和抗病力的影响     

吴亚楠  柳鹏  李强  姜传俊  李华 《大连水产学院学报》2011,26(4):338-343

将以黄芪、党参为主药并加入另外5味中草药所配伍的复方中草药粉碎制剂,以质量分数分别为0%（对照组）、0.5%、1.5%和2.5%的剂量添加于基础饲料中,连续投喂仿刺参Apostichopus japonicus37d,在试验开始后第1、2、3、4周采样,测定仿刺参的肠、触手、体壁、肌肉和体腔液中的抗菌活力及体腔细胞的吞噬活性;于试验开始后第4周,用仿刺参＂化皮病＂病原菌黄海希瓦氏菌Shewanella marisflavi以3.7×108个/mL的浓度在每头仿刺参背部注射0.1 mL的菌悬液,每天观察记录死亡个体症状,统计死亡率,计算相对保护率（共观察记录7 d）。结果显示：各组的抗菌活力均随着用药时间的延长、用药浓度的加大而升高,总体趋势表现为2.5%添加组〉1.5%添加组〉0.5%添加组〉对照组;各用药组仿刺参的体腔细胞吞噬能力均随着用药时间的延长呈现先升高后降低的趋势,第2、3周达峰值,总体趋势表现为1.5%添加组〉2.5%添加组〉0.5%添加组〉对照组;攻毒试验结果显示,对照组仿刺参3 d后全部死亡,第7天各用药组相对保护率依次为1.5%添加组〉0.5%添加组〉2.5%添加组,分别为30.0%、20.0%和10.0%。由此表明,该复方中草药可以显著提高仿刺参的免疫力和抗病力,以1.5%添加剂量组的效果最佳。  相似文献   

Nonregenerative immune‐mediated anemia associated with a diffuse large B‐cell lymphoma in a captive jaguar (Panthera onca)          下载免费PDF全文

Monika A. Keresztes  Manfred Henrich  Penelope Baloi  Sascha Gerst  Jens‐Christian Rudnick  Judith Langenstein  Andreas Moritz  Natali Bauer 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2017,46(4):597-604

An 18‐year‐old male castrated jaguar (Panthera onca) was presented with anorexia and continuous bleeding from the oral cavity after a history of fighting with the partner animal. Clinical evaluation revealed ulcerating lesions on the gingiva and hard palate and a hematoma on the tongue. Computed tomography of the head and endoscopic examination of the esophagus and stomach were unremarkable. Hematology and clinical chemistry revealed severe nonregenerative anemia, mild thrombocytopenia, and moderate azotemia. Several PCRs for feline hemotropic mycoplasmas (Mycoplasma haemofelis, M heamominutium, M turicensis), Babesia felis, and Bartonella spp., as well as an FeLV antigen test were negative. The cytologic examination of a bone marrow aspirate was consistent with ineffective erythropoiesis, most likely due to immune‐mediated destruction of the erythroid precursor cells. Prednisolone therapy was initiated (1.25 mg/kg/day), and the CBC returned to normal 16 days after the initiation of the therapy. Anemia relapsed after 4 months and severe splenomegaly was noted. A repeat bone marrow aspirate revealed active erythropoiesis in the presence of erythroid precursor phagocytosis suggesting an immune‐mediated process. Splenic fine‐needle aspiration and tissue biopsies were taken, and all findings including histology and immunohistochemistry were consistent with a diffuse large B‐cell lymphoma (DLBCL). Five days later, the clinical condition deteriorated and the jaguar died. Histopathology following necropsy showed infiltration with neoplastic lymphoblasts in the spleen, liver, and abdominal lymph nodes. This case report describes a nonregenerative immune‐mediated anemia associated with a DLBCL in a jaguar.  相似文献   

奶牛乳腺免疫细胞防御机理研究进展     

赵悦  童津津  熊本海  蒋林树 《动物营养学报》2020,(4):1563-1569

奶牛乳腺中的初级吞噬细胞、嗜中性粒细胞(PMN)和巨噬细胞构成了抵御病原体入侵的第1道防线。在健康奶牛的乳腺中,巨噬细胞占主导地位且充当哨兵的角色。当病原体侵入乳腺时,巨噬细胞及乳腺上皮细胞就会释放出直接将PMN迁移到该区域的趋化剂,使PMN从循环中迅速流入并吞噬和杀灭细菌,起到保护的作用。抵御病原体入侵的第2道防线是由记忆细胞和免疫球蛋白组成的网络,它们与第1道防线相互作用。随着分子生物学技术的发展,更好地了解炎症反应的调节机制可为研究和调节宿主与病原体的相互作用提供理论基础,因此本文就奶牛乳腺免疫细胞防御机理的研究进展进行了综述。  相似文献   

Circulating melanin-containing cells and neutrophils with phagocytized melanin granules in a horse with disseminated melanoma     

Francisco O. Conrado  Nicholas Iapoce  Mainity Batista-Linhares  Sharleen Lopez  Morgan H. Matthews  Caroline A. McKinney  Caitlin Rothacker 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2020,49(4):624-631

An 18-year-old, grey, Thoroughbred Cross gelding was referred to the Cummings School of Veterinary Medicine at Tufts University following a 3-week history of low-grade fever of unknown origin, distal limb swelling, and weight loss. Clinical examination identified a few black, round, smooth nodules along the ventral aspect of the proximal tail. Transabdominal ultrasound showed a markedly enlarged heterogenous spleen, hyperechoic liver nodules, and evidence of peritonitis with fibrin deposition. A mature neutrophilia was noted on complete blood count with variable numbers of phagocytized granules within neutrophils. The granules did not stain with Perl's Prussian blue, and were intensely positive when stained with Fontana-Mason, consistent with melanin. On necropsy, the spleen occupied approximately one-third of the abdominal cavity and was diffusely firm with abundant black pigment on cut section. The medullary space of the 18th thoracic vertebra was also diffusely blackened. The splenic, mediastinal, and tracheobronchial lymph nodes were five times the normal size and diffusely pigmented. The final anatomic diagnosis was disseminated malignant melanoma with extensive splenic involvement and hemolymphatic and vascular neoplastic dissemination. To the authors' knowledge, this is the first full report to identify circulating neutrophils containing phagocytized melanin granules, which confirmed an antemortem diagnosis of disseminated melanoma.  相似文献   

Polymorphonuclear neutrophil leukocyte function in clinical bovine patients and in cows with or withoutStaphylococcus aureus mastitis     

K. L. Anderson  L. A. Smith  F. J. DeGraves  E. Hunt  S. A. Fleming 《Veterinary research communications》1992,16(2):107-115

A fluorochrome microassay was used to investigate peripheral blood polymorphonuclear leukocyte (PMNL) function in cattle. Glass-adherent PMNL were reacted withStaphylococcus aureus princubated in 20% bovine serum for 30, 60 and 90 min. Coverslips were stained with acridine organge (AO) followed by crystal violet to quench extracellular bacterial fluorescence. PMNL function was evaluated by counting the number of dead (stained red with AO) and live (stained green with AO)S. aureus contained within 100 PMNL. A phagocytic index was calculated as the average number of bacteria contained within PMNL. The percentage killing ofS. aureus was calculated from the average proportion ofS. aureus within PMNL that were dead.Six clinically normal Holstein calves, 3–4 months of age, were sampled on 6 consecutive days. PMNL phagocytosis and killing did not vary significantly (p>0.05) among repeated samplings per calf. PMNL function increased with increasing time of incubation of PMNL withS. aureus. Means (± SD) for percentage killing were 46.7±13.1, 57.4±11.6, and 62.1±9.8% for 30, 60 and 90 min of reaction, respectively. Means (± SD) for the phagocytic index were 2.9±0.8, 3.6±1.0, and 4.2±1.1 bacteria/PMNL for 30, 60 and 90 min of reaction, respectively. PMNL function was determined in 30 normal cattle of various breeds, age and sex, and these values were pooled to provide normal values for PMNL function.When values for bovine clinical patients (n=25) with various diagnoses were compared with normal values (defined by the mean ± 2SD for the 30 normal cattle) for PMNL function, only one patient was observed to exhibit PMNL hypofunction. A cow with disseminated intravascular coagulation in association with peracute coliform mastitis exhibited decreased PMNL killing capacity. Abnormal PMNL function was uncommon in the hospital population studied.Peripheral blood PMNL function was evaluated in lactating Holstein cows with (n=15) or without (n=15) chronic subclinicalS. aureus mastitis. There was no significant (p>0.05) difference in PMNL function among these cows.  相似文献   

调理素的研究进展     

刘娜  韩润林 《中国兽药杂志》2016,50(7):62-65

简述了补体、抗体、C-反应蛋白、血清淀粉样蛋白、甘露糖凝集素、表面活性蛋白、纤粘蛋白等七类调理素的研究,报道了新发现的调理素低密度脂蛋白和高密度脂蛋白,并对抗感染免疫学研究的新视角进行了展望。  相似文献   

Differential effects of experimental hyperthyroidism on declined immunity of broiler chicken          下载免费PDF全文

M. S. Khilji  M. A. Sandhu  M. S. Yousaf  A. A. Saeed  H. U. Rehman  H. Zaneb  M. A. Rashid 《Journal of animal physiology and animal nutrition》2018,102(2):e948-e956

Thyroid hormones (THs) are involved in the development of lymphoid organs and regulation of immune function in birds. However, their role as an immune‐modulator in the hyperthyroid state is still debatable. To explore the interrelationship of thyroxine (T₄) and the immune system, chicks were divided into three groups. Group I was comprised of control birds, who received the basal diet while group II and III were given diets supplemented with 5 μg and 10 μg thyroxine/kg feed, respectively, from 15 to 28 days of age. Cell‐mediated immune response was evaluated through in vitro abdominal macrophage phagocytosis assay, macrophage nitric oxide (NO) production, heterophil‐to‐lymphocyte (H:L) ratio and delayed‐type hypersensitivity response against phytohemagglutinin (PHA). Humoural immune response was assessed through serum IgG and IgM antibody production against sheep red blood cells (SRBCs) and antibody production against infectious bronchitis virus (IBV). Sampling was carried out at 7, 14 and 21 days of treatment. Results have shown higher levels (p < .001) of circulating T₄ in both treatment groups compared to the control group. There was a lower (p < .05) macrophage engulfment percentage, an increase in H:L ratio (p < .001) in treated birds, while their NO production remained higher (p < .05) in thyroxine supplemented groups after bacterial lipopolysaccharide stimulation. The humoural immune response revealed a significant decline (p < .001) in IgG, IgM antibody production against SRBCs but IBV circulating antibodies increased with age. In conclusion, hyperthyroidism has a strong co‐relation with decreased immune performance of birds.  相似文献   

中华绒螯蟹对体内细菌的清除作用     

陆宏达  刘凯 《中国水产科学》2008,15(1):113-121

采用颜料法确定中华绒螯蟹(Eriocheir sinensis)循环血体积(V)与体质量(W)间的回归曲线方程为V=0.1576W-0.898(Rs=0.83,P＜0.01),循环血体积与体质量的百分比(V/W)为(14.86±2.95)%.在确定中华绒螯蟹循环血体积的基础上,通过注射革兰氏阳性蜡状芽孢杆菌(Bacillus cereus)和革兰氏阴性大肠杆菌(Escherichia coli),探讨进入中华绒螯蟹体内细菌随时间变化的清除规律以及通过组织学观察探讨细菌的清除方式.结果表明,中华绒螯蟹对两种细菌的清除作用相似,在注射菌后60 min时对蜡状芽孢杆菌和大肠杆菌的细菌清除率都达到最高,分别为(88.57±4.84)%和(90.15±3.88)%;120 min时对两种细菌清除率与60 min时无显著性差异(P＞0.05).中华绒螯蟹的鳃和心脏中血细胞都可聚集而形成血细胞团,并具有对细菌的包裹和吞噬作用,血细胞团的形成以及包裹和吞噬作用是中华绒螯蟹清除细菌的重要途径.  相似文献