Deck 31: Biofilms: Architects of Disease

Question 1

All of the following organisms are very efficient at converting from planktonic to biofilm biotypes when environmental stresses hit, except

A) coagulase-negative staphylococci.
B) Pseudomonas aeruginosa.
C) Micrococcus luteus.
D) Candida albicans.

Answer 1

C

Question 2

What are the metabolically inert microorganisms present in a biofilm called?

A) Spores
B) Pheromone cells
C) Quorum sensing cells
D) Persister cells

Answer 2

D

Question 3

In which step of the infectious process could biofilms help bacteria when it comes to colonization of indwelling medical devices?

A) Downregulation
B) Phenotypic variation
C) Genotypic variation
D) Attachment

Answer 3

D

Question 4

What is a biofilm?

A) Community of organisms attached to a solid surface
B) The resulting thick, slimy mucous produced in patients with cystic fibrosis
C) A slime factor that can be found in the gastrointestinal tract
D) The resulting film that is produced by necrotic tissue, bacteria, and immune cells

Question 5

In this level of the biofilm, the organisms slightly downregulate their metabolic activity, but they can still use nutrients and exchange genes.

A) Outer
B) Intermediate
C) Inner
D) Substrata

Question 6

Biofilms are a survival strategy for all of the following except

A) planktonic free-floating phenotypes.
B) optimizing nutritional resources.
C) battling shear forces.
D) survival, horizontal gene transfer, and growth.

Question 7

Biofilms can protect its members from

A) antibodies.
B) oxygen-reactive molecules.
C) antimicrobial drugs.
D) All of the above

Question 8

What is stage II of biofilm development?

A) Irreversible binding phase
B) Multiplication phase
C) Attachment phase
D) Layering phase

Question 9

What is stage III of biofilm development?

A) Irreversible binding phase
B) Layering phase
C) Attachment phase
D) Multiplication phase

Question 10

All of the following environmental and key cultural characteristics affect biofilms, except

A) movement of biotic surface.
B) genotypic factors.
C) nutritional resources.
D) mechanical factors and sheer forces.

Question 11

This layer of a biofilm is exposed to the highest concentration of nutrients and oxygen, containing the most active organisms. What layer is this?

A) Outer
B) Inner
C) Middle
D) Substrata

Question 12

What is stage IV of biofilm development?

A) Multiplication phase
B) Thickening phase
C) Cell dispersion
D) Planktonic stage

Question 13

What do biofilms allow members of the microbial community to do?

A) Withstand the shear forces of blood and urine
B) Remain in a nutrient rich environment
C) Survive
D) All of the above

Question 14

Cobiofilms of what two organisms are associated with serious lung infections in cystic fibrosis patients?

A) Pseudomonas aeruginosa and Moraxella
B) Pseudomonas aeruginosa and Burkholderia cepacia
C) Pseudomonas aeruginosa and Mycobacterium tuberculosis
D) Pseudomonas aeruginosa and Streptococcus pneumoniae

Question 15

What is a sessile-type biofilm?

A) A biofilm made up of free-floating microorganisms
B) A multiple-species biofilm
C) A biofilm that is attached and made up of multiple species
D) A biofilm that is present in an aquatic environment

Question 16

How do microorganisms that live in close proximity exchange DNA?

A) Frame-shift mutations and plasmid uptake
B) Transformation and conjugation
C) Conjugation and frame-shift mutations
D) All of the above

Question 17

What process allows the bacteria of the biofilm to spread to other body sites?

A) Conjugation
B) Transformation
C) Disaggregation
D) Planktonization

Question 18

What is stage I of biofilm development?

A) Multiplication phase
B) Irreversible binding phase
C) Layering phase
D) Attachment phase

Question 19

In this level of the biofilm, the organisms downregulate very efficiently and are the least metabolically active.

A) Outer
B) Intermediate
C) Inner
D) Substrata

Question 20

What is stage V of biofilm development?

A) Stationary phase
B) Multiplication phase
C) Cell dispersion
D) Layering phase

Question 21

What types of cells in a biofilm are viable but nonculturable?

A) Phagocytes
B) Persister
C) Attachment cells
D) Layering cells

Question 22

The late colonizers in the dental biofilm include all the following, except

A) Capnocytophaga.
B) Streptococcus salivarius.
C) Selenomonas flueggei.
D) Prevotella spp.

Question 23

What disease, caused by biofilms, consumes more resources in the intensive care unit (ICU) than any other infectious disease?

A) Septicemia with coagulase-negative staphylococci
B) Urinary tract infections due to gram-negative rods
C) Surgical site infections
D) Ventilator-associated pneumonia

Question 24

All the following are laboratory-associated problems related to identifying biofilm-associated diseases, except

A) false-positive cultures.
B) false-negative cultures.
C) viable but noncultural organisms.
D) loss of or decreased antimicrobial susceptibility.

Question 25

Treating infectious diseases has shifted from planktonic susceptibility profiles to

A) therapeutic modalities.
B) creative treatments.
C) multiple interventions.
D) degrading enzymes.

Question 26

What happens to dental plaque if it is allowed to remain undisturbed for several days?

A) The biofilm disaggregates.
B) The persister cells predominate the biofilm.
C) Pathogenic bacteria become the main bacterial constituents of the biofilm.
D) Nonpathogenic bacteria become the main bacterial constituents of the biofilm.

Question 27

What is the common name for a dental biofilm?

A) Cavity
B) Gingivitis
C) Periodontitis
D) Plaque