5.3 - Normal Microbiota Flashcards
Provide the unique role or specific adaptation for Lactobacillus
human niche in the vagina, major protection against vaginosis
Provide the unique role or specific adaptation for Candida albicans
human niche in the vagina, budding yeast, overgrowth with oral antibiotics
Provide the unique role or specific adaptation for Helicobacter pylori
Human niche in the stomach, makes its environment hospitable by raising the pH
Provide the unique role or specific adaptation for Clostridium difficile
Human niche in the colon, 2-10% healthy adults colonized, 20-50% hospitalized adults colonized; forms endospores
Provide the unique role or specific adaptation for Escherichia coli
Human niche in the colon, member of the Enterobacteriaceae; synthesizes vitamin K
Provide the unique role or specific adaptation for Bacteroides
Human niche in the colon, dominant genus in this site; growth stimulated by bile
Provide the unique role or specific adaptation for Propionibacterium acnes
Human niche in the hair follicles, sebaceous glands, produces propionic acid which contributes to stinky feet
Provide the unique role or specific adaptation for Staphylococcus epidermidis
Human niche in the skin, hardy, relatively resistant to desiccation, salt and acid
Provide the unique role or specific adaptation for streptococcus pneumoniae
human niche in the nasopharynx, 5-40% population colonized at this site; known for its capsule
Provide the unique role or specific adaptation for staphylococcus aureus
Human niche in the nose, ~30% population colonized at this site; hardy, relatively resistant to desiccation, salt, acid; produces many toxins
Provide the unique role or specific adaptation for Streptococcus mutans
Human niche is in the mouth, produces acid that demineralize enamel
What is normal microbiota
microorganisms frequently found on or in the body of healthy people
Commensalism
one member benefits while the other is relatively unaffected
Mutualism
both members benefit
Resident microbiota
is a type of colonization. Relatively fixed, washing, sweating doesn’t significantly alter, if disturbed, reestablishes
Transient microbiota
type of colonization, from the environment, food and water, can be either non or pathogenic
Pathogen
always associated with disease
Opportunist
don’t produce disease in their normal environment, but can cause disease when introduced into unprotected sites, or when overgrow their normal environment
Colonization
if the bacteria, fungi… are growing but there is no pathology associated with it
Infection
if the bacteria, fungi… are growing but there is pathology associated with it
What are normally sterile sites?
Amniotic fluid, blood, CSF, synovial fluid, deep tissues, organs, brain, sinuses, middle and inner ear, and internal eye.
If microbes are present it is usually diagnostically significant.
What sites are normally sterile but can have transients?
Larynx, trachea, esophagus, bronchioles, lower airways.
What are sites that are not sterile?
Hair follicles, stomach, upper respiratory tract, mouth, nose, pharynx, perineum, vagina, colon, and skin.
What are the roles of normal microbiota?
- Participate in end stages of food digestion
- Provide some vitamins
- Help protect against pathogens
- Contribute to maturation of immune system
- Stimulate immune response
- Competition for binding sites, space
- Relatively constant unless exogenous factors like acid neutralization antibiotic treatment, which will disrupt balance.
What is Dysbiosis?
Refers to microbial imbalance on or inside the body.
What is CDAD?
Clostridium difficile-associated diarrhea
How is CDAD a dysbiosis?
Antibiotic treatment kills normal flora and allows C. diff to bind and multiple as many strains are antibiotic resistant, they release toxin and cause diarrhea
