� Know the following definitions: infection; virulence; endogenous infection; exogenous agents; endogenous agents; opportunistic infection; toxemia; bacteremia; viremia
1. infection: growth and multiplication of a microbe in or on the body with or without the production of disease
2.virulence: is the degree of pathogenicity or a measure of disease severity
3.endogenous infection:occur when normal flora is introduced to a
� Know what normal (resident) flora is --also known as microflora or microbiota
o Know the positive impacts of normal flora (slide #20)
1. Exclude potential pathogens
>microbial antagonism: Normal microbiota are unlikely to be displaced by incoming microbes
2. Provide some nutrition to the host (i.e. vitamins)
3. Immune stimulation
4. Can also have potential negative impacts (i.e. opportu
Know the harmful effects of the absence of normal flora (slide #21)
>Vitamin deficiencies, especially vitamin K and vitamin B12
>Increased susceptibility to infectious disease
>Poorly developed immune system, especially in the gastrointestinal tract
>Lack of "natural antibody" or natural immunity to bacterial infection
� Know when the human body is first colonized with normal flora and how newborns acquire normal flora
Aquire noral flora through:
>Birth canal
>Breast milk
>Bottle-feeding
>People
>Air
>Surfaces
*The only time that humans are sterile is when they are in the womb (in utero)
� Know the difference between resident and transient flora
1.Transient Microflora
microbes present for shorter periods of time (minutes to months)....just passing through!
- most are harmless, some are pathogens
2.Opportunists
- cause disease when given opportunity
- breakdown in immunity
- certain medical treatm
� Know which sites of the body typically harbor normal flora (i.e. skin; gastrointestinal tract, etc.)
- Skin and its contiguous mucous membrane
-Upper respiratory tract
-Gastrointestinal tract (mouth, colon, rectum, anus)
-Outer opening of urethra
- external genitalia
- Vagina
-External ear and canal
-External eye (lids, lash follicles)
� Know the parts of the body that typically do not harbor resident flora (sterile sites of the body)
1. There are some areas of the body such as the brain, the circulatory system and the lungs are intended to remain sterile (microbe free).
�Know the difference between opportunistic pathogens and strict pathogens
1.Opportunistic pathogens are typically members of normal flora and cause diseases when they are introduced into unprotected sites or when host defenses are compromised, usually occur in people with underlying conditions.
2. Strict pathogens are more viru
�Know the description of an infectious dose (ID); know that microbes with smaller IDs have greater virulence
the only way infection proceeds; microbes with smaller IDs have greater virulence
�Know the portals of entry and exit; know how a pathogen might gain entry into a host using the portals of entry and how a pathogen can potentially exit the body (i.e. microbes can be released from the respiratory tract by coughing or sneezing)
Portals of entry
- Skin - nicks, abrasions, punctures, incisions
The largest organ of the body
Unbroken skin is nearly impenetrable by most organisms
Some grow in hair follicles and sweat gland ducts
- Gastrointestinal tract - food, drink, and other inges
�Know the structures that are used by microbes in establishing an infection (see slide #38 entitled "attaching to the host"); be sure to also look at structures depicted in the diagrams on that slide (i.e. spikes, capsule, etc.)
1. Structures used for attachment:
- Fimbrae
- Capsules
- Flagella
- Glycocalyx
- Cilia
- Suckers
- Hooks
- Barbs
- Spikes (viruses)
�Know the difference between endotoxins and exotoxins (see slide #47 and chart on slide #53)
Endotoxin - toxin that is not secreted, but is released after the cell is damaged
- Composed of lipopolysaccharide (LPS), part of the outer membrane of gram-negative cell walls
- has a variety of systemic effects on tissues and organs
- causes fever, infl
�Be able to describe/recognize the stages of an infectious disease (i.e. incubation period, prodromal period, etc.)
1. Incubation period: Time interval between initial infection and first appearance of signs and symptoms.
2. Prodromal period: Short period characterized by appearance of first mild signs and symptoms (nonspecific).
3. Period of illness: Disease is most s
�Know the difference between signs and symptoms of disease (if you understand the difference between these two terms, you will be able to identify the examples of each).
Earliest symptoms of disease as a result of the activation of the body defenses
Chills, pain, soreness
Signs of inflammation:
Fever
Swelling
Edema - accumulation of fluid
Granulomas and abscesses - walled-off collections of inflammatory cells and microbes
�Know the following definitions as it pertains to an infection: local; systemic; focal; primary; secondary; subclinical
- Local: limited to small area of body (ex. pimple)
- Systemic: spread throughout body via blood (ex. bacteremia, viremia)
- Focal: spread from local infection to specific areas (ex. infection in tooth or tonsils spreads to nearby organ)
systemic infectio
�Know the difference between communicable and non-communicable diseases
1. Communicable disease - a disease that is spread from one host to another
- Receiving host must become infected (ex. common cold, meningitis)
- Highly communicable disease is contagious (ex. measles, influenza)
> diseases that are easily and rapidly spr
�Know the following definitions: epidemiology; epidemic; pandemic; endemic; sporadic
Epidemiology-The study of the frequency and distribution of disease and health-related factors in human populations
Epidemic -when prevalence of a disease is increasing beyond what is expected
Pandemic -epidemic across continents
Endemic -disease that exh
�Know the main purpose of the Centers for Disease Control and Prevention (CDC)
Epidemic -when prevalence of a disease is increasing beyond what is expected
Pandemic -epidemic across continents
�Know the difference between a vector (biological and mechanical), carrier, reservoir, zoonotic, and a fomite when discussing disease transmission.
- a vector (biological and mechanical):
>Biological vectors - actively participate in a pathogen's life cycle; they are infected
>Mechanical vector - not necessary to the life cycle of an infectious agent and merely transports it without being infected; t
�Know what a nosocomial infection is and the most common type of nosocomial infection (UTI; you can find this info in the pie chart on slide #79)
- Urinary tract infection