MCB 2000 Lecture Notes - Lecture 1: Botulinum Toxin, Microbial Toxin, Flaccid Paralysis
Document Summary
Microbes and human body: three types of microorganisms. 1: normal microbiota microorganisms colonizing the human body without harming it, transient microbes rapidly lost, pathogenic microbes invade and damage the cells and tissue. Acquiring resident biota: the uterus is germ-free, first exposure to microbes occurs during the passage through the birth canal, feeding, contact with the environment and family members. Establishing the infection: the microbes enter the body through portal of entry, attaching to the host, surviving host defenses, causing disease. How microorganisms enter a host: portals of entry, mucous membrane (lines the body cavities that are open to the environment, skin (openings or cuts) Is the number of invading microbes important: a certain (minimal) number of microbes have to enter the body in order to cause an infection infectious dose. Infectious dose for: q fever (rickettsia) 1 cell, tuberculosis 10 cells, gonorrhea 1000 cells, cholera 1,000,000,000.
