Chapter 13 Flashcards
Surfaces of our body that have normal flora? List 6
Skin Conjunctiva Nasal cavity and nasopharyngeal Mouth and intestinal tract Vagina Urethra
What’s the process of how you become infected? List 7
Pathogenicity Portals of entry Attachment Surviving host defenses Causing disease Process of infections and disease Portals of exit
What factors weaken host defense and increase susceptibility to infection? List 7
- Old age and extreme youth
- Genetic defects and acquired defects in immunity
- Surgery and organ transplant
- Organic disease: cancer, liver malfunction, diabetes
- Chemotherapy/ immunosuppressive drugs
- Physical and mental stress
- Other infections
Portals of Entry? List 6
Skin GI Tract Respiratory tract Urogenital Placenta Inoculum size
What steps must a pathogen take to successful? List 7
- maintain a reservoir (a place to live before and after infection.)
- Leave the reservoir and enter a host.
- Adhere to the surface of a host.
- Invade the body of the host.
- Evade the body’s defenses.
- Multiply within the body.
- Leave the body and return to its reservoir or enter a new host.
Incubatory Carrier is what?
Seemingly healthy people who are affected but do not develop symptoms.
Chronic Carriers
Have harbored pathogen for months or years
What is Horizontal transmission?
Human contact
What is vertical transmission?
Mother to infant
Across placenta or perinatal (before or after birth)
What is vehicles transmission?
Inanimate objects
Fomites
Not a reservoir
Vectors
Biological- transmitted by bite, defecation, infected with pathogen
Mechanical-not part of pathogens life cycle (fly touch poop and land on you sandwich)
Anthropod
Fecal- oral route? List 4
- Infected feces to mouth of new host
- Direct hand to hand
- Hand to mouth by VEHICLES such as water, food and formites
- Vectors (flies to food)
What’s is parenteral transmission?
Microorganisms are deposited directly into blood vessels or deep tissue
- biological vector bites through skin
- IV drug users share needles
- deep wounds or puncture wounds allowing anaerobic pathogens to enter
What is resident biota?
Inhabit the body throughout life, can never be reduced
Transient biota
Inhabit our body under certain circumstances and can be removed by cleansing.
Opportunists
Bacteria that cause disease when the host defense are weakened, or normal flora is altered.
Cause disease in immune compromised host. Gain access (injury) to sterile regions
What happens at 2 weeks of birth.
General colonization of normal flora.
What happens at 6 months?
Bacteria colonize gum line.
Streptococci
Fusobacterium
Bactericides
how do bacteria change in vagina?
The increase or decrease of lactobacilli.
What is commensalism?
Healthy humans and their normal flora
What is mutualism?
Usually neither survives without the other. Example: digestive bacteria
Parasitism
Pathogenic bacteria. Some commensals could become pathogenic under the right circumstances (makes them opportunist)
What is an structural defense?
Skin
What is a mechanical defense?
Blinking Mucocilliary Talking Swallowing Chewing
What is a biochemical defense?
Salt in sweat
Stomach acid
Tears
Saliva- lysozyme
Name 3 basic defenses?
Structural
Mechanical
Biochemical
What are bacteriocins?
Defensive toxins that inhibit competition
What is a true pathogen
Cause cease in healthy individual. Specific and recognizable disease
Flu
List 4 microbial environment of the Skin.
- Very dry
- Fatty acids can be inhibitory
- Lysozyme in sweat
- Salt can be inhibitory
How does normal biota keep the skin healthy?
By occupying space
What type of bacteria is found on the skin?
Staphylococcus
Diptheroids
Fungi
Mites
Where are Diphtheroids found on body?
Sebaceous Glands
Live deep in hair follicles, feed on sebum
Bacteroides come from where?
Gram negative, bacillus bacteria
They are non-endospore forming, anaerobes
What causes most wound/procedure site infections.
Staph. Epidermidis
Where is the first place to be colonized on human body?
The mouth
Why is the mouth a violent place for bacteria?
Talkin
Chewing
Swallowing
Dislodge bacteria
What is lysozyme?
Biochemical that constantly washes out the mouth
How many different species in the normal flora?
80
What causes tooth decay
Mutans
What kind of bacteria is yeast and thrush?
Candida albicans
How much bacteria is in feces
1/3 dry weight of feces
