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β-内酰胺酶抑制剂舒巴坦的研究进展 总被引：5，自引：0，他引：5
β-内酰胺类抗生素通过共价键与细菌细胞壁合成有关的青霉素结合蛋白(PBPs)而抑制细菌细胞壁的合成,选择性好,是很重要的一类抗感染药物[1].但近年来,耐药菌株的产生,使其疗效大大下降.β-内酰胺酶的产生是细菌对该类抗生素产生耐药的主要机制,对于细菌因产生β-内酰胺酶而引起的耐药性已成为临床治疗中的严重问题[2,3].在对待产酶耐药菌的感染时,使用β-内酰胺酶抑制剂,将其与β-内酰胺类抗生素结合,保持甚至加强β-内酰胺类抗生素的抗菌活性,不失为一快捷、有效的方法[4]. 相似文献
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青霉素结合蛋白(Penicillin binding proteins,PBPs)是广泛存在于细菌表面的一种膜蛋白.PBPs为细菌细胞壁主要结构成分肽聚糖合成过程中所必需的转肽酶,对细菌生长发挥重要的作用.PBBs属于β-内酰胺类抗生素作用的主要靶位,各种β-内酰胺类抗生素通过与PBPs共价结合从而抑制PBPs的酶活性,阻碍细胞壁肽聚糖的合成,使细菌细胞壁缺损,导致菌体膨胀崩解[1]. 相似文献
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β-内酰胺酶抑制剂与β-内酰胺类抗生素联用在兽医学上的应用 总被引：1，自引：0，他引：1
陈志华 《广东畜牧兽医科技》2003,28(6):17-19
20世纪40年代,第一个β-内酰胺类抗生素青霉素的研制和应用,开创了抗生素治疗细菌性疾病的光辉时代。但细菌的耐药性也因抗生素的广泛应用而变得日益普遍,细菌对β-内酰胺类抗生素最主要的耐药机制是产生β-内酰胺酶,破坏β-内酰胺环使抗生素失活。β-内酰胺酶抑制剂的研制应用,恢复了β-内酰胺类抗生素的有效性,使β-内酰胺类抗生素得以继续发挥其在临床上强大的治疗作用。本文主要综述了β-内酰抑制剂的作用机制及其与β-内酰胺类抗生素联用的抗菌活性,以及在兽医临床上的应用概况。为有效地应用β-内酰胺类抗生素控制耐药菌感染提供参考。 相似文献
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超广谱β-内酰胺酶(Extended spectrum betalactamases,ESBLs)是一类能够赋予细菌对多种β-内酰胺类抗生素和单酰环类抗生素耐药的酶类,许多革兰氏阴性菌,如肠杆菌科、铜绿假单胞菌和鲍曼不动杆菌等均可以产生不同类型的ESBLs,如TEM、SHV、CTX-M等类型,还有一些较少报道的VEB、GES和PER型[1]。细菌可以通过多种途径获得这些ESBLs基因,其中转座子、整合子、接合性质粒等可移动遗传元件在捕获和转移这些 相似文献
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头孢菌素属于β内酰胺类抗生素,由于其对大多数革兰阳性菌及许多革兰阴性菌有杀灭作用,具有抗菌谱广、抗菌作用强、在组织体液中浓度高、不良反应相对较轻、过敏少等特点。因此,出现了广泛使用和滥用现象,导致细菌对头孢菌素的耐药率明显升高,不良反应日趋显现,同时加重了患者的经济负担。因此,了解和掌握各代头孢菌素药物的特点及不良反应,科学、合理的使用头孢菌素类抗生素就显得尤为重要。 相似文献
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1生物化学机理1．1细菌产生破坏抗生素结构的酶β-内酰胺酶是细菌对β-内酰胺类抗生素耐药的主要原因。由于β-内酰胺酶的产生，使其β-内酰胺环的酰胺键断裂而失去抗菌活性。该类酶可为染色体介导，也可为质粒介导。 相似文献
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Association between the cell-wall peptidoglycan and the progenitor toxin of Clostridium botulinum type C 总被引：1，自引：0，他引：1
S H Hyun G Sakaguchi 《Nippon juigaku zasshi. The Japanese journal of veterinary science》1989,51(1):169-176
Clostridium botulinum type C progenitor toxin with a molecular weight of 500 k daltons (C1 L toxin), purified from the bacterial cells, bound at pH 2 to the cell-wall peptidoglycan derived from certain strains. The carbohydrate moiety of the peptidoglycan contained arabinose and galactose at a certain ratio, both of which may directly be associated with the binding. The binding, being dependent on the quality and quantity of the sugars, enhanced the oral toxicity of the toxin to the chicken as well as the mouse. 相似文献
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金属硫蛋白与动物应激 总被引：4，自引：0，他引：4
金属硫蛋白是一类低分子量、富含半胱氨酸的金属结合蛋白,它与应激及应激性疾病有关。文章就应激对金属硫蛋白合成的诱导,金属硫蛋白对应激的保护作用及其机制等问题做了简单介绍,说明金属硫蛋白在动物养殖业中具有广阔的应用前景。 相似文献
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Jana B Kucharski J Jedlińska-Krakowska M Wolińska-Witort E 《Polish journal of veterinary sciences》2005,8(4):275-282
The aim of the study was to determine, using the rat model, whether uterine infections cause an increase in cytokine concentrations in peripheral blood, and whether this increase is accompanied by changes in the pituitary-ovarian axis function. The levels of tumor necrosis factor-alpha, interleukin-1beta, luteinizing hormone, follicle-stimulating hormone, prolactin, progesterone, testosterone and estradiol-17beta in blood plasma as well as the weight of the uterus were determined after intrauterine infusion of lipopolysaccharide (15 microg), peptidoglycan (1 mg) and Escherichia coli (10(6) cfu) suspension on the day of metaestrus. On days 3, 7 and 10 after treatment the rats were sacrificed to collect the blood samples. Inflammation of uterus and vaginal discharge developed in all rats after treatment. The administration of lipopolysaccharide, peptidoglycan and Escherichia coli induced considerable changes in ovarian cyclic activity, mainly diestrus was observed. Application of all these factors resulted in an increase (P<0.05, P<0.01) of plasma levels of tumor necrosis factor-alpha, interleukin-1beta, mainly on day 3 and 7. In the rats receiving pathological factors, the plasma levels of luteinizing hormone, follicle-stimulating hormone, prolactin and estradiol-17beta decreased (P<0.05, P<0.01) whereas progesterone and testosterone increased (P<0.05). These results indicate that in rats, the developing inflammatory process of the uterus following lipopolysaccharide, peptidoglycan and Escherichia coli infusions is connected with an increase of tumor necrosis factor-alpha, interleukin-1beta concentrations in peripheral blood, and is accompanied by changes in the pituitary-ovarian axis function. 相似文献
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Polysaccharide is the major component of bacterial cell that plays a significant role in the interaction between bacteria and their hosts. It aids the identification of bacteria, imparting virulence to the bacteria and adjusting host's immune response as well. Advance genomics research has deciphered several different bacterial polysaccharides sharing a common biosynthesis mechanism. The study of polysaccharides is mainly based on sequence analysis and prediction of genome in combination with metabolite analyses that still requires a detailed study. Researchers are now further focusing on their biosynthetic pathways to unveil the mechanisms underlying the diversity of these bacterial polysaccharides along with the host-pathogen interaction. It will open new doors for vaccine development and other therapeutic methods against pathogenic bacteria, and also provide technical support to control disease and cure at molecular level. This review states the mechanisms and relevant problems of biosynthesis and in vitro biosynthesis of peptidoglycan,O-antigen and capsular polysaccharides,and summarizes the application of bacteria polysaccharides in the aspects of searching for candidate antigens and controlling the targets of pathogenic bacteria and exploring genetic evolution of bacteria and biological synthesis. 相似文献
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多糖是细菌细胞的主要组成部分,在细菌与宿主的相互作用中起到重要作用,在参与细菌与宿主的识别,帮助细菌产生毒力,调节宿主免疫反应等生物过程中扮演着重要的角色。随着基因组学的发展,人们发现尽管细菌多糖的种类很多,但它们的合成机制具有相似性。多糖生物合成的研究主要基于基因组的序列分析预测,结合代谢产物研究的基因分析,不够详尽。随着研究的深入,人们越来越关注细菌多糖的合成机制,这种机制的研究将为进一步阐明细菌多糖多样性的形成机制及与宿主间的相互作用机制奠定基础,为开发针对相应病原菌的新型疫苗和治疗方法,及进一步实现分子水平的相关疾病防控和资源开发提供技术支持。作者以肽聚糖、O-抗原和夹膜多糖为代表,阐述了其生物合成及体外生物合成机制的研究进展和相关问题,并总结了细菌多糖合成途径的研究在寻找候选抗原和控制病原细菌靶位以及研究细菌遗传进化和生物合成方面的作用。 相似文献
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Rongrong ZHANG Ting LEI Yanmei QI Peng LEI Zhilong CHEN Xiaodong CHEN Zaiqing YANG 《Animal Science Journal》2010,81(4):425-431
Adenosine diphosphate‐ribosylation factors (Arfs) are a family of guanosine triphosphate‐binding proteins involved in fundamental biological processes including secretion, endocytosis, phagocytosis, cytokinesis, cell adhesion and tumor cell invasion. We report here the molecular cloning, chromosome localization and expression analysis of porcine Arf1–6, of which Arf1–3 (Class I) have >93% similarity to each other and encode nearly similar proteins with 181 amino acids in length. Arf4 and Arf5 (Class II) are 78–81% homologous to Class I Arfs and both encode a protein of 180 amino acids, Arf6 (Class III) shows 64–68% homology to the other Arfs and encodes 175 amino acids. With radiation hybrid mapping, porcine Arf1–6 are assigned to chromosomes 14q21‐q22, 12p14, 5p12‐q11, 13q21.1, 18q24, 1q21‐q27, respectively. Moreover, real‐time quantitative RT‐PCR assays show that porcine Arf1‐6 are ubiquitous in all tissues examined, with the highest levels in the kidney and stomach and the lowest in muscle and the heart. This is the first report of molecular characterization of the Arf gene family in pigs. 相似文献
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The 16-androstene steroids, one of the principal causes of boar taint, are synthesized in the testis by the andien-beta synthase enzyme system. This system has been shown in vitro to involve both cytochrome P450c17 and cytochrome b5. The objective of this work was to investigate the relationship between the levels of cytochrome b5 in the testis, in vitro steroidogenesis, and the accumulation of 16-androstene steroids in the fat of pubertal boars. We found that the in vitro rate of 16-androstene steroidogenesis in testis microsomes was correlated with 16-androstene steroid concentrations in fat (r = .66, P < .01). Western blots were used to determine the amounts of cytochrome b5 and cytochrome P450c17 protein in testis, and two immunoreactive cytochrome b5 proteins of approximately 12 and 16 kDa were found. Levels of cytochrome P450c17 or the high molecular weight cytochrome b5 in testis were not significantly correlated to levels of 16-androstene steroids in fat. However, levels of total cytochrome b5 immunoreactive protein and levels of the low molecular weight immunoreactive cytochrome b5 were correlated to fat 16-androstene steroid concentrations (r = .59, P < .001; r = .72, P = .0001, respectively). Levels of the low molecular weight immunoreactive cytochrome b5 were also correlated to 16-androstene steroid synthesis rates in vitro (r = .62, P < .05). These results indicate that increased levels of a low molecular weight immunoreactive cytochrome b5 protein, and not of cytochrome P450c17, are related to increased testicular 16-androstene steroid production and accumulation in fat. These results support the hypothesis that selection for reduced levels of this low molecular weight immunoreactive cytochrome b5 protein in the testis may result in decreased levels of 16-androstene steroids in fat and reduced boar taint in uncastrated male pigs. 相似文献
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S. Axiak-Bechtel B. Fowler D.H. Yu J. Amorim K. Tsuruta A. DeClue 《Research in veterinary science》2014
Dogs with lymphoma have altered innate immunity and little is known about the effects of chemotherapy on innate immune function in dogs. Lipopolysaccharide (LPS), lipoteichoic acid (LTA), and peptidoglycan (PG) – induced leukocyte cytokine production capacity, and phagocytosis and respiratory burst were evaluated in dogs prior to and following 6 weeks of chemotherapy. Dogs had decreased TNF production following LPS stimulation and increased IL-10 production following PG stimulation, which did not improve following remission of lymphoma. Dogs also had reduced E. coli-induced respiratory burst function after chemotherapy induced complete or partial remission. Dogs with lymphoma have an imbalance in pro-and anti-inflammatory cytokine production which did not improve with remission, and, following treatment, a decrease in respiratory burst function. Altered immune responses following exposure to bacterial pathogen associated molecular pattern motifs and bacteria may have many implications in the management of canine lymphoma. 相似文献