1/26/2016 Relationships between the Normal SYMRIOGES Microbiota and the Host Commensalism:one organism Symbiosis is the relationship between normal benefits,and the other is microbiota and the host unaffected -Commensalism:one organism benefits,and the Staphylococcus epidermidis other is unaffected that inhabit the skin Mutualism:both organisms benefit the surface of the eye -Parasitism:one organism benefits at the expense mycobacteria that inhabit of the other w四2 the ear Some normal microbiota are opportunistic pathogens These bacteria live on secretions and sloughed off cells but bring no harm to the host L8oog nisms bene m both Parasitism:one organism Escherichia coli that inhabit benefits at the expense of the the large intestine other Many disease-caus baec2earepaasi2 Host absorbs and uses these HIN1 (a new influenza virus) vitamins virus particles on a host cell -In return,the lar used by the bacteria to survive 1/26/2016 5 Relationships between the Normal Microbiota and the Host • Symbiosis is the relationship between normal microbiota and the host – Commensalism: one organism benefits, and the other is unaffected – Mutualism: both organisms benefit – Parasitism: one organism benefits at the expense of the other • Some normal microbiota are opportunistic pathogens – Commensalism: one organism benefits, and the other is unaffected – Staphylococcus epidermidis that inhabit the skin – corynebacteria that inhabit the surface of the eye – mycobacteria that inhabit the ear – These bacteria live on secretions and sloughed off cells but bring no harm to the host Mutualism: both organisms benefit – Escherichia coli that inhabit the large intestine synthesizes vitamin K and some B vitamins – Host absorbs and uses these vitamins – In return, the large intestines provide nutrients used by the bacteria to survive Parasitism: one organism benefits at the expense of the other – Many disease-causing bacteria are parasites – H1N1 (a new influenza virus) virus particles on a host cell