Ch. 3 - Host-Microorganism Interactions Flashcards
Any subjective evidence of disease noticed by the patient himself
Symptoms
3 factors for disease
- status of the host’s immune system
- protection from microbial invasion
- inherent microbial factors
Any objective evidence of disease that is detected by a physician; measurable
Signs
Association of 2 organisms living together
Symbiosis
Association of 2 organisms that benefit both
Mutualism
Organisms that live together
Symbionts
Association of 2 organisms where 1 benefits and the other is neutral
Commensalism
Association of 2 organisms where 1 benefits at the expense of the other
Parasitism
Association of 2 different bacterial species that live together; 1 organism enhances the growth of the other
Synergism
Type of microbial flora that are commonly found in/on body sites
Normal/usual/indigenous flora
Type of microbial flora that colonizes an area for months or years
Resident microbial flora
Type of microbial flora that is present at a site temporarily
Transient flora
3 types of microbial flora
- normal/usual/indigenous flora
- resident microbial flora
- transient flora
Hosts with pathogenic organisms without manifesting symptoms.
They are capable of transmitting the infection.
Carriers
The condition of the host (acute/chronic)
Carrier state
2 factors that determine the composition of the usual microbial flora
- amount and type of nutrients available
- pH
Type of infection caused by microorganisms with low virulence that becomes pathogenic in a host with low immunologic resistance
Opportunistic infection
Microorganisms with low virulence
Opportunists
Invasion or growth of a pathogen
Infection
Type of disease with functional and structural harm; with signs and symptoms
Infectious diseases
Disease having sever symptoms and a short course
Acute
Disease with long duration and slow progression; symptoms may be continual or intermittent
Chronic
Disease that is dormant; it is present but not evident
Latent
Disease that is transmissible by direct or indirect means
Communicable
Disease that is not capable of being passed on
Non-communicable
Disease that can transmitted directly
Contagious
Disease that occurs occasionally or in a few isolated areas.
Occurs in single and scattered areas.
Sporadic
Disease that is constantly present in people of a certain class or in people living in a particular location
Endemic
Any infectious disease that develops and spreads rapidly to many people at the same time
Epidemic
Disease that spans the whole world
Pandemic
Disease that originates in and is confined to one organ system or general area in the body
Local
Disease that is limited to a small area of the body
Focal
An initial disease arising spontaneously. It is not associated with or caused by a previous disease
Primary
Disease that follows and results from an earlier disease
Secondary
Disease without a clinical sign, no noticeable illness
Inapparent
Multiplication of microorganisms in the blood; blood poisoning
Septicemia
Presence of bacteria in the blood
Bacteremia
Presence of bacterial toxins in the blood
Toxemia
Presence of pyogenic microorganisms in the blood; formation of multiple abscesses and pus
Pyemia
Prsence of putrefactive bacteria in the blood
Sapremia
Spread of the disease
Incidence
Severity and length of time a disease affects a population
Prevalence
Factors that make the body more susceptible to disease; may alter the course of the disease
Predisposing factors
9 predisposing factors
- habits
- environment
- lifestyle
- pre-existing illness
- fatigue
- age
- chemotherapy
- emotional disturbance
- gender
Patterns of disease (5)
- incubation period
- prodromal
- illness
- decline
- recovery/covalescence
The time between exposure to an infection and the appearance of the first symptoms
Incubation period
Period of time between the appearance of the first symptoms of an infectious disease and the development of a rash or fever
Prodromal
Peak of infection of the disease
Illness
3 reservoir of infection
- human
- non-living
- animal
Human reservoir of infection
Carrier
Animal reservoir of infection
Zoonoses
6 ways of transmissing infection
- contact
- vehicles
- vectors
- airborn
- cuts & bites
- zoonoses
Inanimate object that is capable of transmitting infectious organisms from one individual to another
Fomite
2 types of transmission by contact
Direct and indirect
Example of airborne transmission
Droplet
Example of transmission by vehicles
Polluted dust
2 types of microorganisms
- normal flora/microbiota
- pathogens (true/opportunistic)
Ability of a microbe to produce disease in a susceptible individual
Pathogenicity
Infection that occurs as the result of medical treatment or procedurs
Iatrogenic infections
Relative ability of a microorganism to cause disease
Virulence
Number of microbes affecting 50% of the population
ID50 (Infecting dose)
Number of microbes killing 50% of the population
LD50 (Lethal dose)
A discrete and organized covering of bacteria that impairs phagocytosis; prevents engulfment and destruction by leukocytes
Capsule
Cell surface structure that mediates attachment
Adhesins
Cell wall component that enables bacteria to adhere to host cell surfaces offering resistance by attachment to target cells thereby increasing the organism’s colonizing ability
Fimbriae (pili)
Enzyme that clots fimbrin in blood to create a protective barrier against host defenses
Coagulase
Enzyme that destroys neutrophils by causing lysosomal discharge
Leukocidins
A type of leukocidin that is lethal to leukocytes and contributes to the invasiveness of the organism
Panton-Valentine
Enzyme that dissolves clots to allow escape from isolated wounds
Kinase
2 examples of kinases
Streptokinase and staphylokinase
Enzyme that destroys hyaluronic acid allowing deeper invasion
Hyaluronidase
“Glue” that holds the CT and epithelium barriers together
Hyaluronic acid
Enzyme that breaks down collagen for invasion into muscles and organs
Collagenase
2 types of toxins
- exotoxins
- endotoxins
Organisms that produce exotoxins
Gram positive
Organisms that produce endotoxins
Gram negative
Type of toxin that has a specific effect for a particular cell structure or function in the host
Exotoxins
2 types of exotoxins
- cytotoxins
- neurotoxins
Cytotoxin that causes massive RBC destruction
Hemolysin
Cytotoxin that is related to food poisoning and causes diarrhea
Enterotoxin
Cytotoxin that inhibits protein synthesis
Diphtheria toxin
Cytotoxin that causes skin layers to separate and slough off
Exfoliative toxin
Condition that is caused by exfoliative toxin
Staphylococcal scalded-skin syndrome (SSSS)
Cytotoxin that is linked with absorbent tampons
Toxic Shock Syndrome Toxin (TSST-1)
Cytotoxin that causes valodilation that results in characteristic rash in scarlet fever
Erythrogenic toxin
Neurotoxin that prevents transmission of nerve impulses causing flaccid paralysis
Botulinum toxin
Type of toxin that causes general effects such as fever, weakness, aches and shock
Endotoxins
Effects of endotoxin (5, in order)
- Induction of macrophages to produce IL-2
- IL-2 induces the hypothalamus to produce prostaglandins
- Prostaglandins reset the body’s thermostat to a higher temperature
- high body temperature produces fever and shock
- fever and shock decreases blood pressure
Infection acquired from the hospital
Nosocomial infection
Infection acquired outside the hospital
Community-acquired infection
Infection that is outside the body
Exogenous
Infection that is inside the body (tuberculosis)
Endogenous
Organisms that release enterotoxin
- E. coli
- S. aureus
Organism that produces a toxin that inhibits protein synthesis
Corynebacterium diphtheriae
Organism that produces exfoliative toxin
S. aureus
Organism that produces erythrogenic toxin
Streptococcus pyogenes
Organism that produces a toxin that prevents transmission of nerve impulses causing flaccid paralysis
Clostridium botulinum
