Most Pathogens That Acquire Entry Through The Skin
Few, if any, different microbial products have been as extensively studied as bacterial endotoxins. Perhaps it is appropriate that a molecule with such important biologic results on the host, and one produced by so many bacterial pathogens, should be the topic of intense investigation. Some micro organism (e.g., Rickettsia species) can grow only inside eukaryotic cells, whereas others (e.g., Salmonella species) invade cells however don’t require them for growth.
A) Body temperature is reset in the hypothalamus.B) Fever occurs.C) IL-1 is released.D) LPS is launched from gram-negative micro organism.E) Phagocytes ingest gram-unfavorable micro organism. All of the next micro organism release endotoxin EXCEPTA) Clostridium botulinum.B) Salmonella typhi.C) Neisseria meningitidis.D) Proteus vulgaris.E) Haemophilus influenzae. Which of the next statements about staphylococcal enterotoxin is FALSE? A) It causes vomiting.B) It causes diarrhea.C) It is an exotoxin.D) It is produced by Staphylococcus aureus growing within the host’s intestines.E) It is a superantigen. The fimbriae of Neisseria gonorrhea and enteropathogenic E.
In General, The Ld50 For Exotoxins Is Much Higher Than The Ld50 For Endotoxins
Other micro organism have developed elaborate mechanisms to extract the iron from host proteins (Fig. 7-6). Siderophores are substances produced by many micro organism to capture iron from the host. The absence of iron triggers transcription of the genes coding for the enzymes that synthesize siderophores, as well as for a set of floor protein receptors that acknowledge siderophores carrying bound iron. The binding constants of the siderophores for iron are so high that even iron sure to transferrin and lactoferrin is confiscated and taken up by the bacterial cells.
The availability of full genome sequences for a number of bacterial pathogens coupled with bioinformatics will lead to vital advances toward this goal. Staphylococcus aureus is a ball-shaped bacterium which could be observed as a grape-like clustered organism under the microscope. Cells are sized between zero.eight and 1.2 µm, Gram-positive and non-motile.