Bacterial Pathogenesis: a Molecular Approach
Abigail A. Salyers
Format: PDF / Kindle (mobi) / ePub
Discover the strategies bacterial pathogens use to survive and multiply.
- Focuses on core principles based on the growing understanding of the underlying similarities among pathogens and their mechanisms of action, and is a recommended text for one-semester microbiology courses.
- Presents the latest research to help students explore the mechanisms by which bacterial pathogens cause infections in humans and animals.
- Includes new coverage of key findings on the mechanisms of bacterial secretion, toxins, and regulation.
set of tools for studying bacterial disease processes (Table 10–1). Of particular use is the combined strategy of comparing the host responses in immunodeficient transgenic animals to infection with wild-type bacteria or with mutant bacterial strains that have specific deletions in bacterial virulence factors. This approach allows researchers to better understand the role of the bacterial virulence factor in pathogenesis. For example, Nramp1 (natural-resistance-associated macrophage protein 1) is
researcher, and there may or may not be some theoretical underpinnings to the choice. These problems do not make the correlation studies inappropriate but need to be appreciated. If the approach is treated as one for potentially generating hypotheses rather than as a method that provides a proof of cause and effect, the objections disappear. As more mathematicians and physicists become interested in infectious diseases, more sophisticated modeling approaches will doubtless emerge. A Brave New
not inactivate the toxin, and if antibiotic therapy is delayed for even a few days, enough toxin will have been produced to cause death. Vaccination of the entire population is not practical for such a rare disease, so scientists are seeking chemicals that neutralize the toxin. In the case of a disease called septic shock that develops when gram-negative bacteria enter the bloodstream, a nonprotein component of the bacterial cell surface, lipopolysaccharide, acts as a toxin that leads to organ
infection, the transmigration process is accelerated. To compensate for this loss of PMNs from the bloodstream, the release of PMNs from bone marrow into the bloodstream is markedly increased. Thus, although passage of these phagocytic cells from the bloodstream into tissue is increased, the net effect is a higher concentration of innate-defense cells in the blood. A high level of PMNs in the blood is a useful diagnostic indicator of infection. During an infection, The Innate Immune System PMNs
seen in tissues of infected people, but attempts at cultivation had been unsuccessful. Finally, using this technique, the gram-positive bacterium associated with Whipple’s disease was identified as Tropheryma whipplei. 16S RRNA GENE-BASED PROFILING OF COMPLEX MI- Scientists are often interested in understanding the effects of certain conditions or factors over time on the composition of the CROBIAL COMMUNITIES. 16S rRNA gene variable region Conserved region Double-stranded DNA containing