Definitions Microbial pathogenesis--process of causing disease Colonization-presence of microbes at site of body Does not imply tissue damage or disease symptoms Does imply invasion of site and multiplication BIOL 533 Lecture one
Lecture One BIOL 533 2 Definitions • Microbial pathogenesis—process of causing disease • Colonization—presence of microbes at site of body – Does not imply tissue damage or disease symptoms – Does imply invasion of site and multiplication
Characteristics of Parasitism Encounter: agent meets host Entry: agent enters host Spread: agent spreads Multiplication: agent multiplies Damage: agent, host response or both cause damage Outcome: agent or host wins or coexist BIOL 533 Lecture One
Lecture One BIOL 533 3 Characteristics of Parasitism • Encounter: agent meets host • Entry: agent enters host • Spread: agent spreads • Multiplication: agent multiplies • Damage: agent, host response, or both cause damage • Outcome: agent or host wins, or coexist
Encounter In utero Do not normally come in contact with organisms Protection of fetal membranes Do not normally come in contact with organisms from mother Normally only present sporadically Exceptions: sexual diseases virus causes rubella BIOL 533 Lecture One
Lecture One BIOL 533 4 Encounter • In utero – Do not normally come in contact with organisms • Protection of fetal membranes • Do not normally come in contact with organisms from mother – Normally only present sporadically – Exceptions: sexual diseases, virus causes, rubella
Encounter At moment of birth Come in contact with organisms present in vaginal canal and on skin Previously, antibodies passed from mother to fetus Defenses are good for a period of time, then they wane BIOL 533 Lecture one
Lecture One BIOL 533 5 Encounter • At moment of birth – Come in contact with organisms present in vaginal canal and on skin • Previously, antibodies passed from mother to fetus • Defenses are good for a period of time, then they wane
Encounter Challenge between man and microbe wages many times during lifetime Most disappear rapidly Some become part of normal flora Only a few cause disease BIOL 533 Lecture one
Lecture One BIOL 533 6 Encounter • Challenge between man and microbe wages many times during lifetime – Most disappear rapidly – Some become part of normal flora – Only a few cause disease