MICB 202 Lecture Notes - Skin Flora, Extracellular Polymeric Substance, Human Microbiota
Document Summary
Need normal flora to develop normal immune system: colonization at birth, from environment: dirt, food, fluids, inhalation, contact w/ people and animals, stable micro-flora established rapidly, mostly first from contact with mother. Secondary infection can follow bronchitis or pneumonia: normal flora of urogenital, urine + urogenital tract usually sterile, vagina, distal urethra have bacteria. Lactobacillus in vagina: protects against pathogens by lowering ph with lactic acid production, without them, get utis, bacteria in gi tract all anaerobes, flora establish by its ligands bind to host cell receptors eg. capsules, cell wall components. If animals isolated w/o bacteria: underdeveloped immune system, very susceptible to pathogens, low ab titer, thin intestinal walls, abnormal features. Biofilms: are everywhere, where bacteria form communities, 2/3 of all bacterial infections=caused by biofilms. On medical equipment and heart valve impants, catheters, hemodialysis equipment: form on surfaces, edges, bottoms of aqueous environments, examples, slippery rocks in stream, slippery roof, ship hull coatings causing corrosion, harmful biofilms in diseases.
