BIO 245 UPDATED EXAM SCRIPT QUESTIONS AND
SOLUTIONS RATED A+
✔✔Microbiota of the Skin: Consist of? - ✔✔-Primarily associated with GLANDS
Consist of:
1) Sweat (sudoriferous) glands
-Widely distributed
2) Apocrine glands
-Restricted to underarms, genitals, etc.
3) Sebaceous glands
-associated with hair follicles
✔✔Who's on the skin? - ✔✔-Bacteria
-Fungi
-Viruses
-Protozoa
-Archaea
✔✔Bacteria (4 main phyla) - ✔✔-Actinobacteria (36-51%)
-Firmicutes (24-34%)
-Proteobacteria (11-16%)
-Bacteroidetes (6-9%)
✔✔Who's on the skin (Bacteria): - ✔✔Moist sites: dominated by 2 Genera:
-Staphylococcus
-Corynebacterium
Oily sites:
-Cutibacterium
Dry areas:
-More variable
✔✔What are the bacteria of moist sites on skin? - ✔✔-Staphylococcus
-Corynebacterium
✔✔What are the bacteria of oily sites on skin? - ✔✔-Cutibacterium
✔✔What are the bacteria of dry sites on skin? - ✔✔-Vary
✔✔Cutibacterium: - ✔✔Previously called Propionibacterium
-Gram +
-Aerotolerant anaerobe
, -Prefer oily areas because (sebum) --> feed on fatty acids
-linked to ACNE
-Associated w/ grapevines
Resistance:
-Macrolide resistance is common (erythromycin--> 50% strains tested)
✔✔Who's on the skin (Fungi): - ✔✔-Malassezia (80% of skin fungi)
(Lipophilic yeasts) --> (need oil) -->
(lack fatty acid enzymes, depend on host)
-Cryptococcus
-Rhodotorula
-Aspergillus
-Epicoccum
✔✔Microbiota of human MOUTH: Positives & negatives - ✔✔(Great place to live)! in
contrast to skin
Negatives: salivary enzymes
(lysozyme & lactoperoxidase)
✔✔Microbiota of human MOUTH: Initially at birth - ✔✔-Only limited # of bacterial types
(like lactobacillus & streptococcus)
- (aerotolerant anaerobes)
-Then, --> teeth grow-->more bacteria present in crevices and on smooth surfaces
✔✔Dental Caries: How they begin? - ✔✔-Begin as thin film of glycoproteins in saliva
-This is colonized quickly by streptococcus--> grow to microcolonies
Extensive growth: --> Results in formation of thick biofilm
✔✔plaque (mouth): - ✔✔Accumulates calcium salts to form tartar
✔✔Biofilms (mouth): - ✔✔-Microbial megacommunities
-Can form on any water-associated surface
✔✔How do biofilms attach to mouth/teeth? - ✔✔(attach via production of extracellular
polymer matrix)
✔✔Biofilm development (5 stages): - ✔✔1-Reversible attachment
2-Irreversible attachment
3-First maturation phase
4-Second maturation phase
SOLUTIONS RATED A+
✔✔Microbiota of the Skin: Consist of? - ✔✔-Primarily associated with GLANDS
Consist of:
1) Sweat (sudoriferous) glands
-Widely distributed
2) Apocrine glands
-Restricted to underarms, genitals, etc.
3) Sebaceous glands
-associated with hair follicles
✔✔Who's on the skin? - ✔✔-Bacteria
-Fungi
-Viruses
-Protozoa
-Archaea
✔✔Bacteria (4 main phyla) - ✔✔-Actinobacteria (36-51%)
-Firmicutes (24-34%)
-Proteobacteria (11-16%)
-Bacteroidetes (6-9%)
✔✔Who's on the skin (Bacteria): - ✔✔Moist sites: dominated by 2 Genera:
-Staphylococcus
-Corynebacterium
Oily sites:
-Cutibacterium
Dry areas:
-More variable
✔✔What are the bacteria of moist sites on skin? - ✔✔-Staphylococcus
-Corynebacterium
✔✔What are the bacteria of oily sites on skin? - ✔✔-Cutibacterium
✔✔What are the bacteria of dry sites on skin? - ✔✔-Vary
✔✔Cutibacterium: - ✔✔Previously called Propionibacterium
-Gram +
-Aerotolerant anaerobe
, -Prefer oily areas because (sebum) --> feed on fatty acids
-linked to ACNE
-Associated w/ grapevines
Resistance:
-Macrolide resistance is common (erythromycin--> 50% strains tested)
✔✔Who's on the skin (Fungi): - ✔✔-Malassezia (80% of skin fungi)
(Lipophilic yeasts) --> (need oil) -->
(lack fatty acid enzymes, depend on host)
-Cryptococcus
-Rhodotorula
-Aspergillus
-Epicoccum
✔✔Microbiota of human MOUTH: Positives & negatives - ✔✔(Great place to live)! in
contrast to skin
Negatives: salivary enzymes
(lysozyme & lactoperoxidase)
✔✔Microbiota of human MOUTH: Initially at birth - ✔✔-Only limited # of bacterial types
(like lactobacillus & streptococcus)
- (aerotolerant anaerobes)
-Then, --> teeth grow-->more bacteria present in crevices and on smooth surfaces
✔✔Dental Caries: How they begin? - ✔✔-Begin as thin film of glycoproteins in saliva
-This is colonized quickly by streptococcus--> grow to microcolonies
Extensive growth: --> Results in formation of thick biofilm
✔✔plaque (mouth): - ✔✔Accumulates calcium salts to form tartar
✔✔Biofilms (mouth): - ✔✔-Microbial megacommunities
-Can form on any water-associated surface
✔✔How do biofilms attach to mouth/teeth? - ✔✔(attach via production of extracellular
polymer matrix)
✔✔Biofilm development (5 stages): - ✔✔1-Reversible attachment
2-Irreversible attachment
3-First maturation phase
4-Second maturation phase
