HTHSCI 2HH3 Lecture Notes - Lecture 2: Respiratory Tract, Neisseria Meningitidis, Human Microbiota
22 May 2015
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Document Summary
Microbe few are pathogenic, can benefit the host or colonize without causing disease. Host host factors influence the relationship between the host and microbe. Commensalism- one organism benefits, saprophytic mycobacteria on the ear and genitals, cause no harm or benefit. Indirectly benefit us as they prevent pathogens from using their resources. Mutualism both organism benefit, ex escherichia coli in the large intestine synthesizes vitamin. Parasitism one organism benefits from the relationship at the expense of another. Normal flora permanently colonize the host but do not produce disease under normal conditions. No normal flora in the blood or heart. Areas containing normal flora: upper respiratory tract, upper gi tract, gu tract, lower digestive tract, eyes and skin. Colonize without causing disease, benefit the host by preventing other microbes from growing aka microbial antagonism. Normal flora competes with pathogens for nutrients, produce substances to harm pathogens and change the host environment (increase/decrease ph and o2)
