bmic topic 1.2.1: interactions between man and microorganisms

what is symbiosis?

different organisms living together and interacting with each other

these interactions can be positive or negative

these interactions can be between?

microbe - microbe

microbe - higher organism

what are the 3 forms of interaction?

mutualisms

commensalism

parasitism

what is mutualism?

both organism benefit

what is an example of mutualism?

E. coli in our intestine synthesizes vitamin K which we need while we provide shelter and food

what is commensalism?

only one organisms benefit the other neither benefit or suffers

what is an example of commensalism?

normal microflora which are present on body surfaces

what is parasitism?

only one organism benefit the other suffers

what is an example of parasitism?

covid 19

what is a pathogen?

microbe that has the potential to cause disease

what is an infection?

entry and multiplication of pathogenic microbes in an individual or population

what is the normal microbial flora?

body bacterial population

how can the microbes of the normal flora affect a host?

aid the host

harm the host

exist as commensals

what parts of the human body is free from microbes?

all internal organs and parts of the body are axenic and dree from microbes

what are the internal organs and parts

heart lungs

blood lymph

what part of the body is colonized by microbes

exposed surfaces like skin and mucous membranes are colonized by microbes

what is a resident flora?

resides permanently on our body cannot be totally removed and colonized bodies soon after birth

what is an example of a resident flora?

staphylococcus epidermis

what is a transient flora?

microorganisms that are transferred onto our bodies from the environment and stay temporarily

what is an example of transient flora?

staphylococcus aureus

what are benefits of normal flora in terms of establishment of pathogens

prevent the establishment of pathogens by competing for available nutrients and producing products that will kill

what are benefits of normal flora in terms of immune system

primes the immune system, and induces resistance to infection in the host

what are benefits of normal flora in terms of contribution of nutrients

contributes nutrients to the host

what are harmful effects of normal flora: abnormal conditions

under abnormal conditions normal flora can cause diseases and will become opportunistic pathogens

what are the abnormal conditions that will cause harmful effects of normal flora

normal flora enter unusual site

host immunity is compromised

balance of normal flora is disturbed