final exam Flashcards
living interactions between two organisms
symbiosis
both symbionts benefit in the relationship
mutualism
bacteria in GI tract or protozoa in termite intestines is what relationship
mutualism
one symbiont benefits in the relationship while the other is not affected
commensalism
hair mite and human is example of what relationship
commensalism
on symbiont is harmed while the second is unaffected
amensalism
and example of amensalism is
penicillium and bacteria
one symbiont is harmed while the other symbiont benefits
parasitism
the microbes that colonize the body without causing disease
microbiome
the microbes that remain part of the microbiome most of the humans life
residential microbiota
microbes that remain part of the microbiome for hours to months
transient microbiota
when does microbe colonization befine
birth
normal microbiota that do not normally cause disease may become harmful if the opportunity arises
oportunistic pathogens
what helps opportunistic pathogen cause disease
- intro of normal microbiota into unusual body site
- immune system suppression
- changes in numbers of normal microbiota
site where pathogens are normally maintained as a course of infection
reservoir
disease that spreads naturally from animal hosts to humans
zoonoses
clostridium species that cause botulism and tetanus are found in
soil
zoonoses can be aquired through
direct contact, consuming animal products, blood sucking insects
examples of non living reserviors
water, soil, food
thin lining of the eyeball
conjunctiva
where do viruses mosltly enter through
eyes
the process by which microorganisms attach themselves to cells
adhesion
attachment proteins are also called
ligands
cannot cause measurable damage or disease to a host
avirulent
invasion of a pathogen, physical presence in the body
infection
subjective characterisitics of a disease that only the patient can feel
symptoms
visible evidence of the disease that can be observed or measured in a lab test
signs
pathogen mulitplies and interferes with body function after infection
disease
signs and symptoms that collectively characterize a disease
syndrome
infection goes unnoticed by the person or has no symptoms
asymptomatic or subclinical
may still have signs by proper lab test like leukocyte counts
subclinical infection
the ability of a microbe to cause disease
pathofenicity
the degree of pathogenicity
virulence
three virulence factors
extracellular enzymes, toxins, and antiphagocytic factors
secreted by pathogen help dissolve or breakdown structural chemicals in body
extracellular enzymesf
four extracellular enzymes
- hyaluronidase- break down hyaluronic acid which helps adjacent cells connect together
- collagenase- breaks down collagen fibers which a major structural proteins
- coagulase- causes blood cells to clot which serves as a hiding place for pathogens
- kinase- allows pathogen to breakdown and digest blood clots
a chemical that destroys tissue or triggers host immune response that results in tissue damage
toxin
presence of toxins in bloodstreme that can be carried far from infection site
toxemia
toxins secreted by a pathogen that either destroy a host cell or interfere with host metabolism
exotoxin
destroys neurons and nervous system tissue
nuerotoxin
general toxin that kills any host cell
cytotoxin
destroys cells in gi lining
enterotoxin
only found in gram negative bacteria cells
endotoxins
example of antiphagocytic chemicals
m protein in streptococcus pyogenes
initial entry of the pathogen into host
incubation period
pathogen continues to multiply and host experiences general symptoms
prodromal period
most severe symptoms and specific to the type of infection
period of illness
pathogen population and severity of symptoms decline
period of decline
host returns to normal function
period of convalescence
pathogens leave host through
portals of exit
transmission of a pthogen by a person to person touching or a touch, bite or scratch from an animal
direct contact
aquiring a microbe from contacting a non-living object
indirect contact by fomite
inanimate objects such as clothing cooking utensils, furniture medical equipment and money
fomites
particles that remain suspended in the air for hours that contain pathogens. they are ejected in the form of fluid when an infected individual coughs, sneezes or exhals
respiratory droplets
aquiring pathogen from object that carries disease
vehicle transmission
when pathogens travel more than 1m via aerosol
airborne transmission
importnat in spread of many gastrointestinal diseases
waterborne trnasmission
human waste with pathogens contaminates water source
fecal oral infection
insect or arthropod that transmits the disease to host
vector
transmit pathogens and serve as host for some stage of the pathogens life cycle it is inside insect
biological vectors
insects that carry the pathogen on a body part such as hair and passively transmit pathogens present on their body to new hosts
mechanical vecotrs
