question
Microbes that colonize the body but do not cause disease under normal conditions
answer
Normal Microbiota/microflora
question
Functions of microflora
answer
1. Digestion and metabolism
2. Produce vitamin/metabolites (B6, K)
3. Protection against infection (takes up resources)
4. Maintenance of structural integrity of gut mucosal barrier
5. Immune modulation
2. Produce vitamin/metabolites (B6, K)
3. Protection against infection (takes up resources)
4. Maintenance of structural integrity of gut mucosal barrier
5. Immune modulation
question
Where do you find microflora?
answer
Skin
Respiratory tract (nose, oropharynx, lungs)
Gastrointestinal tract (oral cavity, stomach & small intestines, large intestine)
Urinary tract (bladder)
Reproductive tract (uterus, vagina)
Respiratory tract (nose, oropharynx, lungs)
Gastrointestinal tract (oral cavity, stomach & small intestines, large intestine)
Urinary tract (bladder)
Reproductive tract (uterus, vagina)
question
Large intestine (colon) bacterial concentration
answer
~10^11/ml
question
Areas lacking microflora
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Blood
CSF
Synovial fluid
Lymph
Muscles
Solid organs (kidney, liver, heart)
CSF
Synovial fluid
Lymph
Muscles
Solid organs (kidney, liver, heart)
question
Factors affecting symbiosis
answer
Host susceptibility (immune status)
Virulence of the microbes
Microbial load
Virulence of the microbes
Microbial load
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Mutualism
answer
Organism 1= benefits
Organism 2= benefits
Example= bacteria in human colon
Organism 2= benefits
Example= bacteria in human colon
question
Commensalism
answer
Organism 1= benefits
Organism 2= neither benefits nor harmed
Example= staphylococcus
Organism 2= neither benefits nor harmed
Example= staphylococcus
question
Parasitism
answer
Organism 1= benefits
Organism 2= harmed
Example= TB in human lung
Organism 2= harmed
Example= TB in human lung
question
If delivered vaginally, baby's gut microflora is similar to
answer
Mother's vaginally flora
Lactobacillus
Lactobacillus
question
Newborn intestine is initially colonized by? And then by?
answer
Lactobacillus
Then by E. Coli early in life--> rest of life
Then by E. Coli early in life--> rest of life
question
If delivered by c-section, baby's microflora is similar to
answer
Mother's/caretaker's skin microflora
suggested to negatively influence allergies, asthma, and other conditions
suggested to negatively influence allergies, asthma, and other conditions
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How are other organisms introduced to a baby?
answer
Breathing, feeding, physical contact with mother/caregivers
question
Microflora of the Anterior nares
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Staphylococcus epidermis (90% of staph)
Staphylococcus aureus
Staphylococcus aureus
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Microflora of the Posterior nares
answer
Staphylococcus pneumoniae (pneumonia, meningitis)
question
Microflora of the Oral cavity
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Staphylococcus mitis
Staphylococcus mutans
Staphylococcus sanguis (cavities)
Staphylococcus mutans
Staphylococcus sanguis (cavities)
question
Microflora of the Pharynx
answer
Haemophilus influenzae= 75% of children/adults have non-typeable form; causes ear infections & sinusitis
Neisseria meningitis
Corynebacterium
Streptococcus pneumoniae
Steptococcus pyogenes
Neisseria meningitis
Corynebacterium
Streptococcus pneumoniae
Steptococcus pyogenes
question
Microflora of the Respiratory Tract
answer
Mucociliary system traps bacteria in the mucus and the cilia move the bacteria up into throat for swallowing
question
Microflora of the GI Tract
answer
Stomach= few pass into small intestine due to pH 2-3
Small Intestine=
-Duodenum: few bc bile salts, pancreatic enzymes, impact of low stomach pH
-Ileum: more alkaline, similar to microflora in colon, gram-negative anaerobes and enteric bacteria
Colon= highest [microbes] in body, >500 species
-Daily elimination of bacteria by peristalsis and mucus flow
-Gram-negative anaerobes
-Spore-forming, gram-positive anaerobes
**E. coli
Small Intestine=
-Duodenum: few bc bile salts, pancreatic enzymes, impact of low stomach pH
-Ileum: more alkaline, similar to microflora in colon, gram-negative anaerobes and enteric bacteria
Colon= highest [microbes] in body, >500 species
-Daily elimination of bacteria by peristalsis and mucus flow
-Gram-negative anaerobes
-Spore-forming, gram-positive anaerobes
**E. coli
question
Effect of O2 on growth of Obligate Aerobes
answer
Only aerobic growth
O2 required for growth
O2 required for growth
question
Effect of O2 on growth of facultative anaerobes
answer
Aerobic and anaerobic growth
Greater growth in presence of O2
Greater growth in presence of O2
question
Most common cause of bacterial meningitis, pneumonia, ear infections
answer
Streptococcus pneumoniae
question
Effect of O2 on growth of Obligate Anaerobes
answer
Only anaerobic growth
Ceases growth in presence of O2
Ceases growth in presence of O2
question
Effect of O2 on growth of Aerotolerant Anaerobes
answer
Only anaerobic growth
Continues growth in presence of O2; O2 has no effect
Continues growth in presence of O2; O2 has no effect
question
Effect of O2 on growth of Micro-aerophiles
answer
Only aerobic growth
Low [O2] required
Low [O2] required
question
Effects of catalase and superoxide dismutase on Obligate Aerobes
answer
Catalase= Positive
Superoxide Dismutase= Positive
Superoxide Dismutase= Positive
question
Effects of catalase and superoxide dismutase on Facultative Anaerobes
answer
Catalase= Positive
Superoxide Dismutase= Positive
Superoxide Dismutase= Positive
question
Effects of catalase and superoxide dismutase on Obligate Anaerobes
answer
Catalase= Negative
Superoxide Dismutase= Negative
Superoxide Dismutase= Negative
question
Effects of catalase and superoxide dismutase on Aerotolerant Anaerobes
answer
Catalase= Negative
Superoxide Dismutase= Positive
Superoxide Dismutase= Positive
question
Effects of catalase and superoxide dismutase on Micro-aerophiles
answer
Catalase= Negative
Superoxide Dismutase= Negative
Superoxide Dismutase= Negative
question
Microflora of the Large Intestine
answer
1. Bacteroidetes (-) = most numerous; Bacteroides, Prevotella
2. Firmicutes (+) = lactobacillus, sterptococcus, staphylococcus
3. Proteobacteria (-) = E. coli, Helicobacter, Hafnia
4. Acinetobacteria (+) = Propionibacterium, Bifidobacterium, Corynebacterium
2. Firmicutes (+) = lactobacillus, sterptococcus, staphylococcus
3. Proteobacteria (-) = E. coli, Helicobacter, Hafnia
4. Acinetobacteria (+) = Propionibacterium, Bifidobacterium, Corynebacterium
question
Probiotics in Colon
answer
Lactobacillus, Hafnia, Bifidobacterium
question
Microflora in Colon
answer
Bacteroides
question
Pathogens in Colon
answer
...
question
Influences upon toddler's gut microflora
answer
Breast feeding, formula feeding, interactions with pets, antibiotic use
question
3-year old gut microflora
answer
4 Phyla= Firmicutes, Bacteroidetes, Proteobacteria, Acinetobacter
Coincides with switch to solid food; Contributes to vitamin synthesis and anti-inflammatory factors
Coincides with switch to solid food; Contributes to vitamin synthesis and anti-inflammatory factors
question
After adolescence gut microflora
answer
Firmicutes, Bacteroidetes, Proteobacteria, Acinetobacter
Diet influences which bacterial species/strains thrive
-High fat, animal-based diet "Western"= low [Bacteroidetes], high [firmicutes], high [proteobacteria]
-High fiber= high [Bacteroidetes], low [firmicutes], low [proteobacteria]
Diet influences which bacterial species/strains thrive
-High fat, animal-based diet "Western"= low [Bacteroidetes], high [firmicutes], high [proteobacteria]
-High fiber= high [Bacteroidetes], low [firmicutes], low [proteobacteria]
question
Old adults >60 years old gut microflora
answer
Loses stability, shifts towards bacteroidetes with reduced diversity
Reduced diversity associated with increased frailty and reduced cognitive performance
** as people age/spend time in a long-term residential facility--> gain long-stay-associated defined population of bacteria associated with frailty
Reduced diversity associated with increased frailty and reduced cognitive performance
** as people age/spend time in a long-term residential facility--> gain long-stay-associated defined population of bacteria associated with frailty
question
What hormone greatly alters the flora of the vagina?
answer
Estrogen production
question
What bacterias predominate the vagina before and JUST after puberty?
answer
Staphylocci, Streptococci, Enteric bacteria
question
During estrogen-producing years what bacteria predominates the vagina?
answer
Lactobacillus, lowers pH and prevent infection such as bacterial vaginitis
question
Microflora of the skin
answer
Skin is dry, acidic
Hair follicles and sebaceous fluids (sebum) support growth of anaerobes (propionibacterium acnes)
Predominantly gram-positive cocci
-Most common = Coagulase-negative Staphylococcus epidermidis
Hair follicles and sebaceous fluids (sebum) support growth of anaerobes (propionibacterium acnes)
Predominantly gram-positive cocci
-Most common = Coagulase-negative Staphylococcus epidermidis
question
Diseases with some studies suggesting changes in microflora can influence development of pathology:
answer
Obesity
C. diff
Autism
Addictions
Depression/Anxiety
Anorexia nervosa
Schizophrenia
IBS, Crohn's, UC
CVD
C. diff
Autism
Addictions
Depression/Anxiety
Anorexia nervosa
Schizophrenia
IBS, Crohn's, UC
CVD
question
Benefits of Lactobacillus
answer
Immune reactivity to maintain microbiota levels
Source of vitamins and nutrients
Proper digestion and gut motility
Resistance to infection
(Gut probiotic)
Source of vitamins and nutrients
Proper digestion and gut motility
Resistance to infection
(Gut probiotic)
question
Leading cause of hospital-acquired diarrhea
answer
Clostridium difficile
Obtained from hospital and nursing home stays or from the soil
Use of antibiotics (clindamycin + ceftriaxone) provide a niche for C. diff to expand/overgrow
Obtained from hospital and nursing home stays or from the soil
Use of antibiotics (clindamycin + ceftriaxone) provide a niche for C. diff to expand/overgrow
question
Treatment with microflora transplant
answer
Patients failed to respond to vancomycin treatment
Pts fed 15 capsules on 2 consecutive days
90% of patients resolved C. difficile diarrhea after consuming the capsules
Pts fed 15 capsules on 2 consecutive days
90% of patients resolved C. difficile diarrhea after consuming the capsules
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