Bacteria and Chronic Infections course is offered by “Coursera”. In this post you will get Bacteria and Chronic Infections Quiz Answer | 100% Correct Answer
Bacteria and Chronic Infections
Offered By ”University of Copenhagen”
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Instructor: Thomas Bjarnsholt
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Module 1 Quiz
1. What is the difference between aerobic and anaerobic bacteria?
- Aerobic bacteria grow best at relative high temperatures, while anaerobic bacteria grow better at low temperatures.
- Anaerobic bacteria grow best with oxygen while aerobic bacteria grow best without oxygen.
- Aerobic bacteria grow best with oxygen; while anaerobic bacteria grow best without oxygen.
- Anaerobic bacteria grow best at relative high temperatures; while aerobic bacteria grow better at relative low temperatures.
2. What is the difference between the Gram-positive and Gram-negative bacteria cells?
- The cell wall of the Gram-positive and the Gram-negative cells are of different chemical composition, and they bind differently to the dye in the Gram stain.
- The proteins in the Gram-positive cell membrane bind the dye in the Gram stain stronger than the proteins in the Gram-negative cell membrane.
- The Gram-positive cells have the cell wall outside the cell membrane, while the Gram-negative cells have two membranes and the cell wall is in between the two membranes.
- The Gram-positive cells have some of their DNA in the cell wall, while the Gram-negative cells have their entire DNA inside the cell membrane.
3. Is it possible for the same bacterium toexist both as planktonic and as biofilm?
- No, only pathogenic bacteria can form biofilms
- Yes, but only in the environment not in the human body
- No, only environmental bacteria can form biofilms
- Yes, most if not all bacteria can exist in both forms
4. What is the main difference between bacteria in planktonic and biofilm mode?
- The size and shape of the bacteria
- The physical aggregation and tolerance to antibiotics and host defense
- The ability to perform quorum sensing (cell to cell communication)
- The color and smell of the bacteria
5. What is the most studied form of bacteria?
- The biofilm form, since this is how most bacteria live
- The biofilm form since this is how Robert Koch observed bacteria for the first time
- The planktonic form, grown in shaking flasks
- The biofilm form and the planktonic form have been equally studied over the years
6. Can the same treatment be used on both planktonic and biofilm bacteria?
- Yes, the growth form of a bacterium does not matter
- No, biofilm bacteria are much more tolerant to antibiotics
- No, planktonic bacteria are more difficult to treat since they can escape antibiotics or host defence
- Yes, but only if they are not resistant to the drug
7. Which part of the infection pathogenesis is impaired in chronic infections?
- Penetration and adhesion to receptors
- Elimination of the microorganism
- Multiplication of the microorganism
- Recruitment of the immune system
8. Which of the following infections are due to biofilm formation?
- Foreign-material associated infections
9. How is an acute infection defined?
- By an infection that can be treated with antibiotics
- By an infection that can be eliminated by the immune system
- By a short-term infection
- By an infection caused by viruses
10. What causes the main pathology of acute bacterial infections?
- The antibiotic susceptibility of the bacteria
- The multiplication rate of the bacteria
- The metabolic activity of the bacteria
- Virulence factors(toxin) production of the bacteria
Module 2 Quiz
1. What is the hallmark of a biofilm?
- Quorum sensing (cell to cell signalling) is turned on
- Attachment of bacteria to a surface
- Aggregation of bacteria and tolerance toward antibiotics and host defences
- Increased virulence of the bacteria causing acute infections
2. How can the tolerance of the biofilm be reversed?
- By using less antibiotics to prevent antibiotic resistance
- By treating the patient with anti-inflammatory drugs to prevent host defences
- By physical disruption of the biofilm the bacteria changes into planktonic state
- By removing the nutrients and oxygen the growth slow down
3. Which part of the host response is important for the development of biofilm infections in the lungs of cystic fibrosis patients?
- Inflammatory response
- Adaptive Immune response.
- Mucociliary escalator
- Innate Immune response.
4. What is the inflammatory response a reaction to?
- Hydrogen peroxide.
- Tissue dammage.
What is consumed by the PMNs during the respiratory burst?
- Reactive oxygen species.
- Molecular oxygen.
6. Which cell types accumulate in the synovial fluid in patients with device related prosthetic knee infection?
- Plasma cells.
- Mast cells.
7. Which type of T-helper cell response is associated with mild lung disease in Cystic Fibrosis patients with chronic P. aeruginosa lung infection?
- Th1 response.
- Th2 response.
- Thαβ response
- Th17 response.
8. In which part of P. aeruginosa biofilms is ciprofloxacin acting bactericidal?
- Only in the areas with low oxygen tension
- At the superficial layers
- Throughout the biofilm
- In the deep layers
9. In which part of P. aeruginosa biofilms is colistin acting bactericidal?
- At the superficial layers.
- Only in the areas with high oxygen tension.
- Throughout the biofilm.
- In the deep layers.
10. What is the reasons for the adaptive tolerance in P. aeruginosa biofilms when treating with beta-lactam antibiotics?
- Low metabolic rates.
- Poor penetration through the alginate matrix.
- Production of beta-lactamases.
- Low oxygen-tension.
Module 3 Quiz
1. Which of the following statements are true concerning the presence of bacteria in the human body?
- Bacteria are found in 10-fold higher numbers than human cells
- Bacterial cells are only present on the skin
- Bacteria are only present when we are sick
- Bacteria are found in numbers approximately equal to that of human cells
2. Which of the following statements are true concerning environmental and commensal biofilms?
- Environmental biofilms have low diversity while commensal biofilms have high diversity
- Both environmental and commensal biofilms have a high diversity
- Both environmental and commensal biofilms have mainly negative impact on human health
- Both environmental and commensal biofilms have low diversity
3. Which of the following bacteria are among the first to adhere to a clean tooth surface?
- Prevotella intermedia and Veillonella
- Streptococcus sanguinis and Streptococcus mitis
- Aggregatibacter actinomycetemcomitans
- Veillonella parvula and Lacobacillus
4. Which of the following virulence factors characterize cariogenic bacteria? (Pick 2)
- Growth and metabolism at low pH
- Production of extracellular polysaccharides
- Production of sulphur and ammonia
5. Which of the following virulence factors are important concerning periodontitis? (Pick 2)
- Activated production of pro-inflammatory cytokines
- The lowering of pH
- Early colonization of the teeth
6. What is the causative factor to most common oral biofilm mediated diseases?
- Change of the environment favoring growth of virulent species
- Multispecies colonization of the teeth
- Introduction of one specific non-commensal bacterium
- All bacteria in dental biofilm are causing disease
7. What is the disadvantage of molecular techniques for identification of skin microbiota?
- Molecular techniques identify too few bacterial species.
- Molecular techniques only identify gram-positive bacteria.
- Molecular techniques do not distinguish between living and dead bacterial organisms.
- Molecular techniques only identify gram-negative bacteria.
8. Which part of the skin is the major physical barrier against invasion by microorganisms?
- The basal layer of the epidermis.
- The subcutaneous fat layer.
- The dermis.
- The outermost horny layer.
9. How often is normal epidermis renewed by shedding of dead skin cells?
- Every month.
- Once daily.
10. Which of the following bacterial species are enhanced in growth by skin moisture?
- Staphylococcus aureus
- Escherichia coli
- Corynebacterium spp.
- Staphylococcus epidermidis
Module 4 Quiz
1. What is the most correct definition of a chronic wound?
- A wound that is in the lower extremity
- A wound present for more than one year
- A wound that is more than three months old
- A wound that will never heal
2. What is likely to be present in a wound that have a one-year history, heals very slowly and is very large?
- Beta-haemolytic Streptococci spp.
- Morganella morgani
- Pseudomonas aeruginosa
- Stahphylococcus aureus
3. Which bacterial species are likely to be present in wounds that heal very slowly, are very large or are older than one year?
- Stahphylococcus aureus
- Beta-haemolytic Streptococci spp.
- Morganella morgani
- Pseudomonas aeruginosa
4. What is the classical method in treatment of a late periprosthetic joint infection?
- Long-term antibiotics
- Two-stage revision (use of cement spacer, two operations)
- Debridement(medical removal of infected tissue)
- Joint washout
- One-stage revision (new implant inserted in same operation)
5. Which of the following is NOT considered a separate type of periprosthetic joint infection?
- Acute late infection
- Acute very late infection
- Chronic infection
- Acute postoperative infection
- Unexpected positive culture from revision procedure
6. Which element is NOT part of the paradigm of typical periprosthetic joint infections?
- Pronounced host response
- Inoculation during surgery
- Spontaneously resolve
- Formation of biofilm on the implants
- Effect of prophylactic antibiotics
7. From where do bacteria and viruses in the middle ear most often ascend?
- From the lung
- From the nasopharyngeal space
- From the blood
- From the lymph
8. What is Otitis media with effusion (OME)?
- An inflammatory middle ear disease
- An acute infection in the middle ear
- Characterized by pus in the middle ear
- A rare middle ear infection
9. What is Chronic otitis media with suppuration (CSOM) characterized by?
- Recurrent nature
- Easy to treat
- Fast recovery
- High incidence
10. Where has human middle ear biofilm infection/inflammation been evidenced?
- In the ear ossicles
- In the inner ear
- In the mucosa of the middle ear
- In the brain
11. The role of biofilm in middle ear infections is
- Proven in animal studies
- Sometimes proven
- Still not proven
- Easy to detect
12. What is Cystic fibrosis?
- It is a lifestyle related condition like obesity
- It is a genetic inherited disease affecting only the respiratory tracts of the patients
- It is a genetic inherited disease affecting multiple organs of the patients
- It is a genetic inherited disease affecting the sight and balance of the patients
13. What is the most severe complication of patients suffering from Cystic fibrosis?
- They suffer from bad sight and chronic headaches
- They suffer from recurrent acute bloodstream infections which slowly degrade their health
- They get chronic lung infections which slowly degrade their lung function
- They get chronic infected wounds in the oral cavity which slowly disable digestion
Module 5 Quiz
1. Are bacteria in biofilms unculturable?
- Yes of course, that is the hallmark of biofilm infections
- No, only if they are attached to a surface
- Yes, bacterial biofilm cannot be cultured on conventional plates
- No, but they have to be correctly sampled, processed and cultured
2. How is the PK/PD parameters of beta-lactams changed in biofilms formed by bacteria producing beta-lactamase?
- From dose-dependent to concentration-dependent
- From time-dependent to concentration-dependent
- From dose-dependent to time-dependent
- From concentration-dependent to time-dependent
3. Which of the following antibiotics has a concentration-dependent killing in planktonic cells? (multible correct answers)
- Aminoglycosides (tobramycin)
- Ciprofloxacin (quinolones)
4. How can the development of antibiotic resistance in biofilms be prevented?
- By low dosages of antibiotics
- By monotherapy (treatment with one antibiotic)
- By a short-period antibiotic treatment
- By a combination therapy (two different groups of antibiotics)
5. Where is bacterial biofilm situated in the chronic wound?
- On the surface, in the wound-tissue and in some cases deeper in the apparently normal tissue
- Only on the surface
- Only in the wound-tissue
- On both the surface and in the wound tissue
6. How can a carrier of local antibiotic diminish development of antibiotic resistance?
- By release of high amount of antibiotic in the beginning and sustain release in lower concentrations for a prolonged period of time
- By release of low concentration of antibiotic in a short periode of time
- By release of low concentration of antibiotic over a long time
- By release of high concentrations of antibiotics in the initial phase, have a short phase of low concentration and release all antibiotics in the end.
7. Which of the following limitations of laboratory culture are true in determining a biofilm associated infection?
- Samples must be disrupted for laboratory culture and therefore in situ localisation of the infection cannot be determined
- It may take days to grow a pathogen or the plates may be blank, due to antibiotic treatment. Additionally, the in situ localisation cannot be determined.
- Culture may take several days to grow a pathogen
- Culture may not indicate an infectious agent due to previous use of antibiotics in the patient
8. Which of the following is NOT a criterion for biofilm infection?
- Evidence of ineffective host clearance with confined areas of PMNs/inflammatory cells surrounding clusters of bacteria
- Aggregated pathogenic bacteria are present
- Infection is localised to a particular site in the host
- Bacteria are associated with a surface
9. Does in vitro biofilms always mimics biofilms in chronic infections?
- Yes, a biofilm can always be recognized by the mushroom shape structures
- No, usually in vivo biofilms are smaller and less structured than in vitro biofilms
- Yes, but the biofilms in chronic infections grow much faster
- No, in vitro biofilms are smaller and less structured than in vivo biofilms
10. What is most effective environmental change in the treatment of chronic infections?
- Surgical revision of the ulcers
- Application of appropriate measures that address the underlying conditions
- Local antiseptics
- Dressing changes
Module 6 Quiz
1. What are ‘pathoadaptive genes’ ?
- Genes that are mutated to provide a fitness disadvantage in relation to host adaptation
- Genes that are expressed during host infection and provide a fitness advantage in relation to host adaptation
- Genes in the host that are mutated to provide a fitness advantage in relation to bacterial infections
- Genes that are mutated to provide a fitness advantage in relation to host adaptation
2. How can Pseudomonas aeruginosa by defined?
- As an opportunistic bacterial pathogen
- As an commensal bacterium
- As a non-pathogenic bacterium
- As a pathogenic fungi
3. What does the concept of ‘within-host evolution’ refers to:
- Evolutionary adaptation of bacterial pathogens during infection
- Evolutionary adaptation of the host in response to bacterial pathogens
- Regulatory adaptation of the host in response to bacterial pathogens
- Regulatory adaptation of bacterial pathogens during infection
4. Which of the following methods/techniques has been instrumental for our understanding of ‘within-host evolution’?
- Systematic sampling and storage of bacterial pathogens, and phenotypic analysis of these pathogens
- Systematic sampling and storage of bacterial pathogens, and whole-genome sequencing of these pathogens
- Whole-genome sequencing of bacterial pathogens and their hosts
- Systematic sampling and storage of bacterial pathogens, and efficient use of antibiotics to eradicate these pathogens
5. What is the primary target of the antibiotic ‘Azithromycin’ ?
- The bacterial cell envelope
- The bacterial transcriptional machinery
- The bacterial ribosome
6. How is the ability of an organism to reproduce and survive described?
- By regulation
- By mutation
- By existence
- By fitness
7. What does natural selection leads to?
- Extinction of the more fit phenotypes
- Dominance of the more fit phenotypes
- Nothing in biofilms – it is irrelevant
- Less adapted populations
8. Which one of these is important in maintaining cooperative traits in microorganisms?
- Toxin production
- Quorum sensing
- Kin selection
9. When does variants with distinct colony morphology occur?
- Never in biofilm or planktonic cultures
- Never in biofilms
- More frequently in biofilms compared to planktonic cultures
- Less frequently in biofilms compared to planktonic cultures
10. Which one of these types of social behaviour provides a fitness cost to the actor and a fitness benefit to the recipient of the behaviour ?
11. What is long-term co-existence important for?
- Bacterial growth rates
- Bacterial mobility
12. Why might biofilm formation limit the spread of non-cooperative cheats?
- Spatial structuring in biofilms keeps coorperating genotypes together.
- Biofilm cells produce toxins that kill or inhibit cheats.
- Cells that cooperate to produce biofilms are fitter and grow faster than cheats.
- Cheats are unable to grow within biofilms.