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Innate immunity and host defense peptides in veterinary medicine 总被引:1,自引:0,他引:1
Linde A Ross CR Davis EG Dib L Blecha F Melgarejo T 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2008,22(2):247-265
Recent years have witnessed a surge in interest directed at innate immune mechanisms. Proper conceptualization of the key elements of innate immunity, however, is still a work in progress, because most research in immunology traditionally has been focused on components of the acquired immune response. The question of why an animal stays healthy in a world filled with many dangers is perhaps as interesting as why it sometimes surrenders to disease. Consequently, studies with an increased focus on inborn mechanisms of animal host defense may help further the development of appropriate preventative and therapeutic measures in veterinary medicine. Host defense peptides (HDPs) are central effector molecules of innate immunity, and are produced by virtually all living species throughout the plant and animal kingdoms. These gene-encoded peptides play a central role in multiple, clinically relevant disease processes. Imbalances in the expression of HDPs can lead to overt pathology in different organ systems and cell types in all species studied. In addition, HDPs are an ancient group of innate chemical protectors, which are now evaluated as model molecules for the development of novel natural antibiotics and immunoregulatory compounds. This review provides an overview of HDPs and is aimed at veterinary practitioners as well as basic researchers with an interest in comparative immunology involving small and large animal species. 相似文献
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This experiment investigated the effect of dietary supplementation with essential oils from Artemisia afra and Moringa oleifera on haemato‐immunological parameters and resistance in Clarias gariepinus (African Sharptooth catfish) (Burchell, 1822) challenged with Aeromonas hydrophila. The experiment lasted for 45 days. Prior to and postchallenge, white blood cells significantly increased (p < .05) from the 3% to 12% M. oleifera and A. afra supplementation. Pre‐challenge, no significant differences (p > .05) in red blood cells, haemoglobin and haematocrit were observed between the control and M. oleifera supplementation, while in the A. afra supplementation, RBC and HCT significantly increased from the 6% to 12%. Postchallenge, RBC, HGB and HCT were significantly lower (p < .05) in the control and the 3% and 6% M. oleifera and A. afra supplementation. Both pre‐ and postchallenge, nitro‐blue tetrazolium levels significantly increased (p < .05) from the 3% to 12% M. oleifera supplementation while no significant differences (p > .05) were observed in lysozyme activity between the control and treatment groups. In A. afra, NBT and lysozyme activities increased significantly (p < .05) from the 6% to 12% supplementation pre‐ and postchallenge. Survival rate increased from the 3% to 12% in M. oleifera and A. afra supplementation groups. Significant kidney histological alterations were noted in the control and the 3% and 6% supplementation of both plants postchallenge, while no major histological changes were observed between treatment groups and the control pre‐challenge. The results demonstrate that EO from M. oleifera and A. afra can improve immunity and enhance survival in C. gariepinus. 相似文献
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FliZ调控枯草芽孢杆菌Bs916生物膜形成 及其对水稻纹枯病的防治效果 总被引:1,自引:0,他引:1
【目的】发掘并鉴定枯草芽孢杆菌(Bacillus subtilis)Bs916生物膜形成调控新基因,检测其对Bs916生物膜形成能力和对水稻纹枯病防治效果的影响。【方法】利用基因同源重组技术构建fliZ基因位点的单敲除突变株,通过干重分析法来验证其生物膜形成的缺陷;利用平板对峙试验检测fliZ突变株和Bs916对水稻纹枯病菌(Rhizoctonia solani)的抑菌效果;利用高效液相色谱(HPLC)检测fliZ突变株和Bs916中影响防治效果的3种脂肽类抗生素表面活性素、杆菌霉素L和泛革素的相对产量;利用绿色荧光标记技术构建Bs916与fliZ突变株的GFP标记菌株,观察两者在水稻茎秆定殖能力变化;检测fliZ突变株和Bs916对水稻纹枯病的防治效果。【结果】成功构建了fliZ位点单敲除突变株,与对照组Bs916的三维立体结构生物膜相比仅能形成平面二维结构生物膜,呈现破碎状态,证明其生物膜形成存在显著缺陷;对生物膜干重进行定量分析发现fliZ突变株生物膜干重仅为对照组Bs916的23%,进一步验证了fliZ突变株生物膜形成能力显著下降;游动性试验发现fliZ突变株菌体扩展直径仅为Bs916的32%,证明fliZ突变株的游动能力显著下降;抑菌试验显示两者抑菌带宽基本一致,证明fliZ突变株对水稻纹枯病菌的抑菌能力与Bs916相比无显著差异;成功检测了fliZ突变株和Bs916合成的3种脂肽类抗生素表面活性素、杆菌霉素L和泛革素的相对产量,fliZ突变株中杆菌霉素L相对产量显著增加1倍,而表面活性素和泛革素相对产量与Bs916相比无显著差异;水稻茎秆定殖试验发现fliZ突变株菌体数量显著低于Bs916,在水稻纹枯病病斑附近不出现显著的聚集效应,呈现无序分布状态,证明fliZ突变株与Bs916相比在水稻茎秆上的定殖能力显著下降;对水稻纹枯病的田间防治效果试验显示,fliZ突变株第6—15天防治效果介于6.0%—20.7%,显著低于Bs916的36.0%—57.6%,证明fliZ突变株对水稻纹枯病防治效果显著下降。【结论】鉴定的Bs916生物膜新调控基因fliZ位于控制鞭毛运动的信号通路,直接作用于菌体的游动与扩张,显著单一调控生物膜形成与对水稻纹枯病的防治效果。 相似文献
158.
为研究鸭疫里默氏菌对诺氟沙星、恩诺沙星、环丙沙星、氧氟沙星、左氧氟沙星等氟喹诺酮类药物的主动外排机制,测定25株鸭疫里默氏菌临床分离株对氟喹诺酮类药物的最低抑菌浓度(M IC ),同时测定加入主动外排抑制剂碳酰氰间氯苯腙(CCCP)后的MIC ,对二者进行比较分析。结果表明,对5种氟喹诺酮类药物耐药的鸭疫里默氏菌比例分别为84%、72%、76%、68%和36%;76%的菌株同时耐受2种及以上药物。CCCP可以使耐药菌对除左氧氟沙星外药物的敏感性增加,提示主动外排在鸭疫里默氏菌对氟喹诺酮类药物的耐药机制中发挥重要的作用。 相似文献
159.
Chunwei Cheng Yan Liu Hao Song Lili Pan Jerry Li Yong Qin Rongshi Li 《Marine drugs》2013,11(8):2927-2948
Methicillin-resistant Staphylococcus aureus (MRSA) continues to be a major problem, causing severe and intractable infections worldwide. MRSA is resistant to all beta-lactam antibiotics, and alternative treatments are limited. A very limited number of new antibiotics have been discovered over the last half-century, novel agents for the treatment of MRSA infections are urgently needed. Marinopyrrole A was reported to show antibiotic activity against MRSA in 2008. After we reported the first total synthesis of (±)-marinopyrrole A, we designed and synthesized a series of marinopyrrole derivatives. Our structure activity relationship (SAR) studies of these novel derivatives against a panel of Gram-positive pathogens in antibacterial assays have revealed that a para-trifluoromethyl analog (33) of marinopyrrole A is ≥63-, 8-, and 4-fold more potent than vancomycin against methicillin-resistant Staphylococcus
epidermidis (MRSE), methicillin-susceptible Staphylococcus aureus (MSSA) and MRSA, respectively. The results provide valuable information in the search for new-generation antibiotics. 相似文献
160.
Use of antibiotics for the control of bacterial diseases in shrimp culture has caused several adverse impacts to the industry. This has resulted in the search for alternative environment friendly approaches to overcome bacterial infections. This study was conducted to investigate the use of beneficial bacteria as an alternative to antibiotics. Ten pathogenic bacterial species isolated from shrimp, Penaeus monodon, and Artemia cysts were tested for susceptibility to indigenous marine Bacillus subtilis AB65, Bacillus pumilus AB58, Bacillus licheniformis AB69 and compared with oxytetracycline, chloramphenicol, gentamicin and bacitracin, which are common antibiotics used in Asian aquaculture. The Bacillus spp. were isolated from the local marine environment for bioremediation use in shrimp hatcheries and were proven to reduce total ammonium nitrogen. The pathogenic bacterial isolates were 90% susceptible to B. subtilis AB65, 70% susceptible to B. pumilus AB58 and B. licheniformis AB69 and 100% susceptible to oxytetracycline, chloramphenicol and gentamicin but only 40% to bacitracin. Two representative isolates of the vibrio group, Vibrio alginolyticus VaM11 and Vibrio parahaemolyticus VpM1, when tested for competitive exclusion by a common broth method using the marine Bacillus spp., showed decreased viable counts from 10(8) to 10(2) cfu mL(-1). The results suggest that the action of the marine bacteria appears to be significant in protecting the host shrimp against pathogenic bacteria. In addition to the alternative use of antibiotics, the selected marine bacteria had additional bioremediation properties of reducing ammonia. 相似文献