protection from pathogens, stimulation of gut maturation, stimulation of innate and adaptive immunity, expansion of nutritional diversity, digestion of complex carbohydrates
how do microbiomes protect the host from pathogens?
stable ecosystems resist introduction or overgrowth of pathogens at epithelial surfaces
what are the negative consequences of the microbiome?
foot odor, flatulence, body odor, bad breath, opportunistic disease, transfer of antibiotic resistant genes to pathogens
what is disease?
any condition in which the normal structure or functions of the body are damaged or impaired
are physical injury and disability classified as disease?
no
what are causes of disease?
infection, genetics, environmental and immune responses
what is infection?
successful colonization of a host by a microorganism, can lead to disease
what are pathogens?
organisms that cause disease
what is virulence?
the degree of pathogenicity
what historical account of disease occurred in 3200 BC?
shememsu of egypt, first recorded epidemic with unknown cause
what historical account of disease occurred in 400 BC?
plague of Athens, could have been caused by measles or typhus
what historical account of disease occurred in 80 AD?
epidemic in livestock and humans in italy, could have been caused by anthrax
what historical account of disease occurred in 1546?
germ theory, seeds of disease
what historical account of disease occurred in 1665-1786?
Hook, Leeuwenhock, and Mueller discovered animalcules
what historical account of disease occurred in 1840?
germ theory plus, contagion is living and may be cultivated outside the host
what historical account of disease occurred in 1860-1864?
formal experiments conducted by Louis Pasteur
what historical account of disease occurred in 1876?
Koch's postulates
what are Koch's postulates?
the microorganism must be present in every case of the disease but absent from healthy organisms
the suspected microorganisms must be isolated and grown in pure culture
the same disease must result when isolated microorganism is inoculated into a healthy host
the same microorganisms must be isolated again from the diseased host
what are the stages of pathogenesis?
exposure, adhesion, and invasion
what is exposure?
encounter with pathogen, requires a portal of entry to gain access to the host
what are portals of entry and why are they important for pathogenesis?
broken skin, mucous membranes, and parenteral routes
pathogens are suited to particular portals of entry
what is adhesion?
attachment to body cells, mediated through adhesins, bind to receptors on host cells, or biofilms can cause adhesion
what are examples of adhesins on the surface of pathogens?