Normal Flora

Question 1

E. coli when when it leaves the intestine becomes it becomes infectious, what type of relationship with the host does E. coli represent here?
A).  Parasitic
B).  Commensuel
C).  Opportunistic
D).  Mutual

Answer 1

Opportunistic. When in the intestine E. coli is part of the normal flora, and mutualistic.

Question 2

S. epidermidis is found on all these bodily structures except: 
A).  Mouth
B).  Cunjunctiva of the eye
C).  Lower Respiratory Tract
D).  Skin

Answer 2

The lower respiratory tract is free of bacteria (sterile)

Question 3

A bacterium is isolated from the large intestine of a healthy individual, thought to be a member of the normal flora. It is most likely to be which of the following?

A). Enterococcus
B). Neisseria meningitidis
C). Staphylococcus aureus
D). Micrococcus luteus

Answer 3

A). Enterococcus

Question 4

Normal microbacteria protect host by all except:

A). Occupying niches that pathogens might occupy
B). Producing antitoxins
C). Producing acids
D). Producing bacteriocins

Answer 4

B. Producing Antitoxins

Question 5

What are superantigens? What is an example of a superantigen?

Answer 5

Super antigen is a antigens that binds a T cell receptor without any ligand which elicits a nonspecific immune response of proliferation of nonspecific T cells. creating a cytokine storm. S. anureus
If not treated can lead to sepsis

Question 6

Mostly gram-positive bacteria live on the skin, which of these is an example of the few gram-negative bacteria that can thrive on the skin?

A). Malassezia furfur
B). S. Epidermidis
C). Actinobacter
D). M. Luteus

Answer 6

Actionbacter is a gram-negative bacteria that live on the skin
S. Epidermidis and M. Luteus both live on the skin but are gram-positive
Malassezia furfur is a fungi

Question 7

Bacteria found on the skin

Answer 7

Gram-positive, salt-tolerant
Staphylococci: S. epiderimidis
Micrococci: Micrococcus Letues
Diptheroids: corynebacterium xerosis - aerobes
Propionibacterium acnes - anaerobe in hair follicles
-Acinetobacter

Question 8

Normal Flora of the Eye

Answer 8

Found in the cunjunctiva of the eye

Staphylococcus epidermidis

Question 9

Normal Flora in the Mouth

Answer 9

They adhere to gums and teeth
Contribute to plaque and gingivitis

Staphylococcus Mutans
Lactobacillus

Question 10

Normal Flora in Mouth and Respiratory Tract

Answer 10

Staphylococcus aureus
Staphylococcus epidermidis

Pharynx and trachea - gram-pos

• staphylococci: S. epidermidis
• Micrococci: M. luteus
• Diphtheroids
• Streptococci (hemolytic)

Question 11

What pathogenic bacteria can be found in the Nasopharynx?

Carriers

Answer 11

Streptococcus pneumoniae
Neisseria meningitis
Haemophilus influenzae
Mycoplasmas

Question 12

Normal Flora of Large Intestine

Answer 12

E. coli, Bacteriodes, Fusobacterium, Enterobacter, Citrobacter, Proteus, Klebsiella, Candida- fungus

Largest population of microbes in the human microbiome

• eliminated by peristalsis, desquamation and mucous movement
• replaced rapidly
• mostly anerobes

Question 13

Normal Flora in Female Genital Tract

Answer 13

Comples, dependent on state of flux - period

Acid tolerant Lactobacilli - H2O2