实验基础

DNA probes are being used increasingly to detect and identify microorganisms, particularly pathogenic bacteria in a variety of areas. These include medicine, the food industry, and the environment. Various strategies have been used to develop DNA probes for specific bacteria that inc ...

Bacteriophages (phages) are viruses that infect bacteria. Susceptibility to infection by particular phages varies between strains within a species, and this property can be exploited to construct highly discriminatory schemes for the type identification of strains in epidemi ...

Bacteriocins are proteins produced by bacteria which are lethal for other members of the same species and, occasionally, for other species. In general, bacteriocins are active in very low concentrations against specific strains. This property has been widely utilized for the identifi ...

Polyacrylamide gel electrophoresis (PAGE) of proteins has been used increasingly during the past decade in the examination of bacteria for both comparative purposes and in the study of their protein biochemistry at the molecular level. The most popular of the techniques employed, disc ...

Lipopolysaccharide (LPS), traditionally termed somatic antigen or O-antigen, forms an integral part of the outer membrane of Gram-negative bacteria. In general, LPS consists of essentially three parts: 1. A hydrophobic portion, lipid A,

The cell envelope of Gram-negative bacteria comprises an inner and an outer membrane separated by a layer of peptidoglycan (Fig. 1). The inner membrane is the site of biochemical reactions involved in respiration and oxidative phosphorylation, and the synthesis of structural membrane c ...

Pyrolysis of microorganisms yields complex mixtures of products that can be analyzed quantitatively by mass spectrometry (MS). The resulting mass spectra represent transient bacterial “fingerprints” that can be compared mathematically for relatedness. The method has poten ...

Mass spectrometry (MS) is a chemical analytical technique that can yield data in the form of a spectrum of peaks of differing relative intensities and over a range of mass-to-charge (m/z) values. Such data permit calculation of molecular weight and molecular structure. The technique has been us ...

Of the world’s infectious diseases, tuberculosis remains the leading cause of mortality and it has been estimated that of the eight million new cases that occur each year 95% are found in the less developed countries (1,2). Diagnostic methods that involve culture of Mycobacterium tuberculos ...

Genomic variation in any organism is of interest, because it may influence the phenotype of the organism. Special interest currently focuses on prokaryotic pathogens regarding mutations associated with resistance to therapeutic drugs, as well as those mutations involved in the evo ...

In principle, restriction fragment length polymorphism (RFLP) typing can be applied to strains of all mycobacterial species for which suitable probes have been identified. International consensus has been achieved regarding the methodology of IS6110 RFLP typing of Mycobacter ...

Culture filtrates obtained by in vitro cultivation of Mycobacterium tuberculosis have been studied for more than 20 years to identify and characterize proteins of immunological relevance. Culture filtrate preparations have been shown to induce a protective immune response in mi ...

Mycobacterium tuberculosis and the other pathogenic mycobacteria examined so far by electron microscopy are seen to be surrounded within host cells by an electron-transparent zone (ETZ). For Mycobacterium lepraemurium, this space between the phagosomal membrane of the infected ...

Mycobacterial cell wall ultrastructure has been studied through the use of negative staining, electron microscopy (1,2), freeze fracture (3), X-ray diffraction (4), differential scanning calorimetry (5,6), and electron spin resonance spectroscopy. Through the use of these techn ...

Great progress has been made in the latter half of the twentieth century in the understanding of the immunology of tuberculosis and of strategies for chemotherapeutic management of this disease. Indeed, given the evidence that the dominant, and perhaps sole, ecologic niche of Mycobacteri ...

Mycobacterium tuberculosis is a facultative intracellular pathogen, which can survive and replicate within the host macrophage. It is transmitted via the aerosol route, which delivers the bacillus to the alveolus of the lungs. The initial phase of granuloma formation within the lung re ...

The ability of pathogenic Mycobacterium to establish and maintain an infection in a host is dependent on their capacity to survive within phagocytes (1–3). Studies conducted on macrophage infections in culture have provided considerable insight into the mechanisms developed by the ...

Molecular beacons are a novel family of hybridization probes, which emit fluorescence upon interaction with their target. They are hairpin-shaped oligonucleotides with a central part complementary to the target, flanked by two 5 6 base pair (bp) inverted repeats, which can form a stable ste ...

Genetic manipulation of mycobacteria has historically been difficult. This is in large part due to the impenetrable nature of the cell wall, resulting in difficulty both in introducing DNA into the bacterium and subsequent isolation of intact plasmid DNA. In addition, the mycobacterial c ...

The complete genome sequence of the well studied laboratory strain of Mycobacterium tuberculosis (H37Rv) has been published by the Sanger Centre (1), and this information will soon be complemented by the completion of a recent clinical isolate of M. tuberculosis (CDC1551/CSU93) by The Ins ...