第九章 肠道杆菌 肠道杆菌(Enteric bacilli)是一大群寄居于人和动物肠道中的革兰氏阴性无芽胞内杆菌,常随人与动物粪便排出,广泛分布于水、土壤或腐物中。 肠道杆菌属于肠杆菌科(Enterobacteriaceae),分类尚未完全统一,过去主要依据生化反应和抗原结构进行分类。近十多年来,应用DNA同源性研究、抗生素敏感谱、种和型特异性噬菌体,以及电子计算机分析技术等,使其分类日趋合理。目前肠杆菌科至少有25个菌属,90个 ...
第八章 病原性球菌 球菌是细菌中的一大类。对人类有致病性的病原性球菌(Pathogenic coccus)主要引起化脓性炎症,又称为化脓性球菌(Pyogenic coccus),其中革兰氏阳性菌主要包括葡萄球菌、链球菌、肺炎球菌;革兰氏阴性菌包括脑膜炎球菌和淋球菌等。 第一节 葡萄球菌 葡萄球菌属(Staphylococcus)是一群革兰氏阳性球菌,因常堆聚成葡萄串状,故名。多数为非致病菌,少数可导致疾病。葡萄球菌是最常见的化脓性球菌,是医院 ...
第七章 细菌感染的诊断和特异防治 细菌性疾病的诊断,除个别因有特殊临床症状不需细菌学诊断外(如破伤风引起的典型挛等)一般均需进行细菌学诊断以明确病因。然而自标本中分离到细菌并不一定意味该菌为疾病的病原,因此应根据病人的临床情况、采集标本的部位、获得的细菌种类进行综合分析。例如自脑脊液中分离出脑膜炎球菌与自鼻咽部可存在脑膜炎球菌的意义即有不同。因脑脊液正常应无菌存在,而5~10%正常人的鼻咽部分可存在脑膜炎球菌,为健康 ...
第六章 细菌的致病性和抗细菌感染的免疫 凡能引起人类疾病的细菌,统称为病原菌或致病菌(Pathogenic bacterium)。细菌在人体内寄生,增殖并引起疾病的特性称为细菌的致病性或病原性(Pathogenicity)。致病性是细菌种的特征之一,具有质的概念,如鼠疫细菌引起鼠疫,结核杆菌引起结核。致病性强弱程度以毒力(Virulence)表示,是量的概念。各种细菌的毒力不同,并可因宿主种类及环境条件不同而发生变化。同一种细 ...
第五章 细菌的遗传与变异 细菌和其他微生物一样,具有遗传性和变异性.。细菌的形态、结构、新陈代谢、抗原性、毒力以及对药物的敏感性等翥是由细菌的遗传物质所决定的。在一定的培养条件下这些性状在亲代与子代间表现为相同,为遗传性。然而也可出现亲代与子代间的变异。如果细菌的变异是由于细菌所处外界环境条件的作用,引起细菌的基因表达调控变化而出现的差异,则称为表型变异。表型变异因为并未发生细菌基因型的改变,不能遗传,所以是是非遗传变异 ...
第四章 细菌的分布与外界环境对细菌的影响 第一节 细菌的分布 细菌种类多、繁殖快、适应环境能力强,因此,细菌广泛分布于自然界,在水、土壤、空气、食物、人和动物的体表以及与外界相通的腔道中,常有各种细菌和其它微生物存在。在自然界物质循环上起重要作用,不少是对人类有益的,对人致病的只是少数。 一、细菌在自然界的分布 (一)土壤中的细菌 土壤中含有大量的微生物,土壤中的细菌来自天然生活在土壤中的自养菌和腐物寄生菌以及随动物排泄物及其尸体进入土壤的 ...
第三章 细菌的繁殖与代谢 细菌具有独立的生命活动能力,可从外界环境中摄取营养物质,获得能量,具有代谢(Metabolism)旺盛、繁殖(Multiplication)迅速的特点。细菌代谢过程中,可产生多种对人类的生活及医字实践有重要意义的代谢产物。 第一节 细菌的营养 细菌从周围环境中吸收作为代谢活动所必需的有机或无机化合物称为营养物质。一种物质可否作为细菌的营养物质,决定于两个因素:①该物质能否经一定的方式进入细胞;②细菌是否具有 ...
第二章 细菌的形态与结构 细菌(Bacterium)是属于原核型细胞的一种单胞生物,形体微小,结构简单。无成形细胞核、也无核仁和核膜,除核蛋白体外无其他细胞器。在适宜的条件下其相对稳定的形态与结构。一般将细菌染色后用光学显微镜观察,可识别各种细菌的形态特点,而其内部的超微结构须用电子显微镜才能看到。细菌的形态对诊断和防治疾病以及研究细菌等方面工作,具有重要的理论和实践意义。 第一节 细菌的大小与形态 观察细菌常用光学显微镜,通常以 ...
Recombinant adenoviruses (AdV) are highly efficient at gene transfer for a broad spectrum of cell types and species. They became one of the vectors of choice for gene delivery and expression of foreign proteins in gene therapy and vaccination purposes. To meet the need of significant amounts of a ...
Even though natural infections with adenovirus (Ad) are largely harmless in humans, an intravenous Ad vector administration for gene delivery purposes, especially at high doses, stimulates strong innate and adaptive immune responses, and can be fatal to the host. In animal models, intra ...
Bacterial artificial chromosomes (BACs) are recombinant DNA molecules designed for propagation of large and instable foreign DNA fragment in Escherichia coli. BACs are used in genetics of large DNA viruses such as herpes and baculoviruses for propagation and manipulation of complex ...
Recombinant adenoviruses provide a versatile system for gene expression studies and therapeutic applications. In this chapter, a standard procedure for their generation and small-scale production is described. Homologous recombination in E. coli between shuttle plasmids a ...
Adenovirus vectors are efficient gene delivery tools. A major caveat with vectors derived from common human adenovirus serotypes is that most adults are likely to have been exposed to the wild-type virus and exhibit active immunity against the vectors. This preexisting immunity limits t ...
High-capacity adenoviral vectors (HC-Ad), also known as “helper-dependent” (HD-Ad), “gutless”, “gutted”, or “third-generation” Ad vectors, are devoid of all viral coding sequences and have shown promising potential for a wide variety of different applications—from classic gene th ...
The use of chimeric pseudotyped vectors is a common way to modify the adenoviral tropism by replacing the fiber protein. In this chapter the procedure to generate a chimeric adenovirus pre-stock from a plasmid containing the adenoviral genome is described. Also, the chimeric adenovirus rep ...
In this chapter we compile a battery of biophysical and imaging methods suitable to investigate adenovirus structural stability, structure, and assembly. Some are standard methods with a long history of use in virology, such as embedding and sectioning of infected cells, negative stain ...
Analysis of proteins and their posttranslational modifications is important for understanding different biological events. For analysis of viral proteomes, an optimal protocol includes production of a highly purified virus that can be investigated with a high-resolving ana ...
Adenoviral vectors hold immense potential for a wide variety of gene therapy based applications; however, their efficacy and toxicity is dictated by “off target” interactions that preclude cell specific targeting to sites of disease. A number of “off target” interactions have been desc ...
During human adenovirus type 3 (Ad3) infection, an excess of penton base and fiber proteins are produced. These form dodecahedral particles composed of 12 pentamers of penton base and 12 trimers of fiber protein. Beside this “natural” expression, the adenovirus dodecahedron can be express ...
Vectors derived from the canine adenovirus serotype 2 (CAV-2) possess a high neurotropism and efficient retrograde transport that lead to widespread neuronal transduction in the central nervous system (CNS) of various animals. These abilities are due to the engagement of virions to the c ...