I Flashcards
is the disturbance in the state of health wherein the body cannot carry its normal function.
Disease
multiplication of the parasite within the host’s body
Infection
organism is present on the surface of the skin and mucous membranes
Contamination
one that benefits from the symbiotic relationship and harms the host
Parasite
harbors the parasite
Host
capacity of the pathogen to produce disease
Pathogenicity
intensity of the disease produced by the pathogens or the degree of pathogenicity
Virulence
factors that are produced by a microorganism and evoke disease
Virulence factors
They are either structural or physiological characteristics that help bacteria to
- invade the host
- cause disease
- evade host defenses
examples of virulence factors
bacterial toxins and enzymes
the outcome of bacterial infections may be influenced by the determinants associated with the
host
pathogen/agent
modifying factors in the environment
the agent meets the host
Encounter
after attachment to receptors of host cells by means of specific adhesion molecules present on its surface.
Entry and colonization
ex. of entry and colonization
-promote attachment in small intestine
pili of K88/K99 of E. coli
proteins that promote tighter binding of bacteria to host cells following initial binding via pili
Adhesins
mechanisms that destroy host defenses such as the production of extracellular matrices such as polysaccharide capsule which is antiphagocytic, inactivation of cellular responses, and interference with the humoral immune responses
Evading host defenses
invading organism must evade host defense mechanisms and must gain access to host nutrients for growth
Multiplication
ability of organism to invoke deleterious effects through toxin production and direct cell and cellular function damage
Damage
ex. of physical barriers
skin
self-cleaning
normal flora
ex. of innate immunity
inflammation
defensins
lysozyme
ex. of specific immunity
antibody production
cell-mediated immunity
period of time beginning with the initial infection through to the point where individual presents clinical signs. The agent localized and begun to multiply; asymptomatic but capable of transmitting the disease agent to others
Incubation phase
short and present non- specific mild signs
Prodromal phase
T or F. All diseases have prodromal phase
False
some do not have
ex. of prodromal phase
redness and swelling
depression
anorexia
characteristic of a particular disease are apparent
Invasive phase
ex. of invasive phase
cough
fever
swollen lymph nodes
vomiting
diarrhea
signs are at greatest intensity; when pathogen has invaded and damaged host tissues
Acme
T or F. Acme can be sudden and severe or chronic; host –pathogen interactions are at their most intense and disease outcome is decided
TRUE
characterized by decline in signs associated with the disease. Secondary infection may occur this time as the immune system has been compromised during the interaction with the original pathogen
Decline phase
host begins to repair the damage caused by the presence of the pathogen, and the host recovers. This phase may be infectious if the disease is associated with scab or accessible lesions
Convalescent phase
major virulence factors
adhesins
capsules
toxins
could be classified on how they are released
toxins
help the bacterium bind to the intestinal epithelium
adhesins
prevents phagocytosis
capsule
elaboration result to various damaging effects to the host
toxins
soluble substances released into host tissues
exotoxins
part of the bacterial cell wall and thus released when the bacterium dies or divide
endotoxins
organisms producing exotoxins
all gram positive: some gram negative
organisms producing endotoxins
almost all gram negative
exotoxin location in the cell
extracellular
endotoxin location in the cell
bound within bacterial cell wall
exo chemical nature
mostly polypeptides
endo chemical nature
lipopolysaccharide complex
exo stability
unstable
endo stability
relatively stable
exo tonicity
among most powerful toxin
endo tonicity
weak but fatal in large doses
exo effect on tissue
highly specific
endo effect on tissue
nonspecific
exo fever prod
little or no fever
endo fever prod
high fever
antigenicity
exo
endo
strong
weak
toxoid conversion and use
exo
endo
toxoid used to immunize against toxin
cannot be converted to toxoid
exo example
Botulism
gas gangrene
tetanus
diphtheria
staphylococcal food poisoning
cholera
enterotoxins
plague
endo example
salmonellosis
tularemia
endotoxic shock
