Deck 23: Wound Infections

Question 1

The most frequent genus causing wound infections in healthy people is

A) Pseudomonas.
B) Staphylococcus.
C) Pasteurella.
D) Rochalimea.
E) Escherichia.

Answer 1

B

Question 2

The popular name for tetanus is

A) hydrophobia.
B) lockjaw.
C) whooping cough.
D) consumption.
E) spasticity.

Answer 2

B

Question 3

The Gram-negative opportunistic rod that can grow in a wide variety of environments, including disinfectants and soaps, is

A) E. coli.
B) S. aureus.
C) P. aeruginosa.
D) S. pyogenes.
E) P. vulgaris.

Answer 3

C

Question 4

Which of the following virulence factors has been associated with Pseudomonas aeruginosa?

A) Endotoxin A
B) Exoenzyme S
C) Pyogenic exotoxin
D) Endoenzyme T
E) Exoenzyme P

Question 5

An important feature of many wounds that may lead to more serious problems is that they are

A) well aerated.
B) relatively anaerobic.
C) nutrient rich.
D) sterile.
E) nutrient rich AND sterile.

Question 6

A striking feature of Clostridium tetani that differentiates it from other pathogenic species of Clostridium is its ability to

A) produce a greenish pigment.
B) grow in strictly anaerobic conditions.
C) grow in strictly aerobic conditions.
D) produce endospores.
E) form terminally located, spherical spores.

Question 7

Formation of biofilms attached to fibronectin and fibrinogen coating plastic devices like catheters and heart valves is a virulence mechanism of

A) Staphylococcus.
B) Streptococcus.
C) Clostridium.
D) Pseudomonas.
E) Escherichia.

Question 8

Which of the following has been associated with flesh-eating disease?

A) H. lechter
B) P. aeruginosa
C) S. aureus
D) S. pyogenes
E) H. pylori

Question 9

Factor(s) not found in abscesses is/are

A) blood vessels.
B) pus.
C) dead leukocytes.
D) tissue remnants.
E) live leukocytes.

Question 10

The researcher who did much of the early work on Clostridium tetani was

A) von Behring.
B) Koch.
C) Kitasato.
D) Pasteur.
E) Clouseau.

Question 11

Which of the following produces a greenish pigment that may appear in infected wounds?

A) P. aeruginosa
B) E. coli
C) S. aureus
D) S. pyogenes
E) E. aerogenes

Question 12

A wound created by the drag of a knife across skin can be classified as a(n)

A) incision.
B) puncture.
C) laceration.
D) contusion.
E) abrasion.

Question 13

Which of the following are involved in coating Staphylococcus with host proteins?

A) clumping factor, leukocidin, AND coagulase
B) coagulase AND protein A
C) leukocidin AND protein A
D) leukocidin AND coagulase
E) clumping factor, coagulase, AND protein A

Question 14

The nodular, red, translucent surface material of a healing wound is called

A) soluble skin.
B) irritated scab.
C) granulation tissue.
D) abscess.
E) collagen.

Question 15

Which of the following is NOT True? Microorganisms in abscesses often are not killed by antimicrobial agents because

A) the microorganisms stop dividing.
B) of the high level of oxygenation.
C) of the chemical nature of the pus.
D) of the lack of blood vessels.
E) of innate resistance in the microbes.

Question 16

Wound healing can be slowed by the presence of

A) normal microbiota.
B) foreign matter.
C) antiseptic ointments.
D) sweat.
E) sweat AND normal microbiota.

Question 17

Which of the following does not usually result from a wound infection?

A) Delayed healing.
B) Aerobic conditions.
C) Abscess formation.
D) Bacterial spread.
E) These all result from delayed wound healing.

Question 18

S. pyogenes associated with invasive disease characteristically have

A) leukocidins AND streptococcal pyrogenic exotoxin A.
B) coagulase AND streptococcal pyrogenic exotoxin B.
C) coagulase AND streptococcal pyrogenic exotoxin A.
D) leukocidins AND streptococcal pyrogenic exotoxin B.
E) streptococcal pyrogenic exotoxin A AND streptococcal pyrogenic exotoxin B.

Question 19

A localized collection of pus in a wound is termed a(n)

A) leukocyte.
B) dead tissue.
C) granulation mound.
D) abscess.
E) scab.

Question 20

The normal habitat of Clostridium tetani is

A) humans.
B) animals.
C) plants.
D) soil and dust.
E) dairy products.

Question 21

Sporotrichosis may result when the infectious agent is introduced into the body by

A) lotions.
B) scissors.
C) thorns.
D) animal bites.
E) insect bites.

Question 22

The most common cause of chronic lymph node enlargement at a localized body site in young children is

A) cat scratch fever.
B) rat bite fever.
C) dead bat fever.
D) mouse itch fever.
E) dog scuff fever.

Question 23

Effective treatment of gas gangrene primarily involves

A) use of an antitoxin.
B) use of myonecrosis immune globulins.
C) surgical removal of dead and infected tissues.
D) vaccination with inactivated toxin.
E) use of synergistic antibiotics.

Question 24

The exotoxin produced by C. tetani is

A) tetanoxin.
B) exotetanus.
C) endospasmin.
D) paraloxin.
E) tetanospasmin.

Question 25

Which of the following has not been associated with human bites?

A) Syphilis
B) Tuberculosis
C) Hepatitis B
D) Tetanus
E) These have all been associated with human bites.

Question 26

The fungal disease that may be associated with gardening is

A) candidiasis.
B) actinomycosis.
C) tinea capitis.
D) sporotrichosis.
E) histoplasmosis.

Question 27

Which is True of leukocidins?

A) They kill neutrophils.
B) They are superantigens.
C) They make holes in host cell membranes.
D) They bind to Fc regions of antibodies.
E) They destroy erythrocytes.

Question 28

Tetanus antitoxin is

A) inactivated toxin.
B) antibody against the toxin.
C) antibody against the bacteria.
D) inactivated bacteria.
E) antibody against neurotransmitter.

Question 29

Rat bite fever, characterized by fever, rash, and muscle aches, is caused by

A) Streptobacillus moniliformis.
B) Afipia felis.
C) Bartonella henselae.
D) Pasteurella multocida.
E) Pseudomonas aeruginosa.

Question 30

Cat scratch fever is caused by

A) Bartonella henselae.
B) Pasteurella multocida.
C) Teddis nugentaea.
D) Staphylococcus aureus.
E) Pseudomonis aeruginosa.

Question 31

The toxin implicated in C. perfringens toxicity is

A) tetanospasmin.
B) exoenzyme S.
C) alpha toxin.
D) endoenzyme T.
E) beta toxin.

Question 32

Which is True about protein A, produced by S. aureus?

A) It binds to the Fc region of antibody AND it enhances binding of phagocytes.
B) It binds to the Fc region of antibody AND it hides bacteria from phagocytes.
C) It hides bacteria from phagocytes AND it digests antibodies.
D) It enhances binding of phagocytes AND it digests antigens.
E) It binds to the Fab region of antibody AND it hides bacteria from phagocytes.

Question 33

Tetanus vaccine contains

A) inactivated bacteria.
B) inactivated spores.
C) live bacteria.
D) inactivated tetanospasmin.
E) inactivated lipopolysaccharide.

Question 34

The infectious agent(s) that may arise in a wound from a human bite is/are

A) Escherichia coli.
B) Bacteroides species.
C) Bartonella henselae.
D) Staphylococcus aureus.
E) Bacteroides species AND Staphylococcus aureus.

Question 35

The disease most feared to develop after an animal bite is

A) tetanus.
B) rabies.
C) gas gangrene.
D) streptobacillary rat bite fever.
E) necrotizing fasciitis.

Question 36

The most common infectious agent acquired from the bite wounds of a number of kinds of animals is

A) Escherichia coli.
B) Pasteurella multocida.
C) Bartonella henselae.
D) Pseudomonas aeruginosa.
E) Staphylococcus aureus.

Question 37

Tetanus prevents the release of neurotransmitters from

A) muscle cells.
B) excitatory neurons.
C) tetano cells.
D) inhibitory neurons.
E) muscle cells AND tetano cells.

Question 38

Streptobacillus moniliformis is unusual in that it

A) forms spores.
B) forms L-forms.
C) is anaerobic.
D) has a cell wall.
E) is unicellular.

Question 39

The disease that involves the muscles and often manifests itself first with spasms of the jaw muscles is

A) tetanus.
B) myonecrosis.
C) streptobacillarosis.
D) necrotizing fasciitis.
E) sporotrichosis.

Question 40

Gas gangrene is so named due to the formation of

A) carbon dioxide AND oxygen.
B) oxygen AND carbon monoxide.
C) hydrogen AND oxygen.
D) carbon monoxide AND hydrogen.
E) carbon dioxide AND hydrogen.

Question 41

Why is it not surprising that Staphylococci are the leading cause of wound infections?

A) This genus is readily present as a part of the normal microbiota on most people's skin, so it could easily enter wounds.
B) Members of this genus are all particularly virulent and highly capable of causing numerous infections.
C) Staphylococci cannot be eradicated from the skin due to multidrug resistance in most members of the genus. Drugs simply don't kill them.
D) Staphylococci acquire antibiotic resistance very readily, making them hard to eliminate by pre-surgical antibacterial soaps. As such, they commonly infect surgical wound sites.
E) Staphylococci form endospores, so even with appropriate control measures, there is a high risk that spores will enter a wound and cause infection.

Question 42

Streptobacillus moniliformis is unusual in that it spontaneously forms L-forms.

Question 43

Tetanus antitoxin can cross the placenta.

Question 44

Clumping factor, coagulase, and protein A serve to coat Staphylococcus with host proteins.

Question 45

Early work with Clostridium tetani and Corynebacterium diphtheriae demonstrated

A) the importance of thoroughly cooking food.
B) the potential threat from spore-forming bacteria.
C) the usefulness of anti-viral medications.
D) that disease can be caused by bacterial toxins.
E) that all bacteria form spores.

Question 46

Why is it not surprising that staphylococci are the most common cause of wound infections?

A) Many people carry staphylococci as part of their normal microbiota.
B) Staphylococci are resistant to most common disinfectants.
C) Unlike other pathogens, the organism evades the immune system very effectively.
D) Staphylococci are encapsulated.
E) Staphylococci are Gram-negative and contain LPS.

Question 47

Bites by little children typically cause few problems.

Question 48

Why might Candida albicans become pathogenic in a person receiving antibacterial medications?

A) This fungal organism can actually use the destroyed bacterial cells as a nutrient source and begin to multiply out of control. This can cause a pathogenic state.
B) This is an opportunistic pathogen not normally found in normal microbiota. As such, when the bacterial normal microbiota is eliminated by broad-spectrum antibacterial drugs, this opportunist can adhere to and colonize the area left behind.
C) This is a usual member of the normal microbiota. However, when the bacterial members of the normal microbiota are killed by a broad-spectrum antibacterial drug, this fungal cell type has little to no competition for resources and it quickly overgrows, causing disease.
D) This is a protozoan species and part of the normal microbiota. When the bacterial members of the normal microbiota are wiped out by a broad-spectrum antibacterial drug, this protozoan cell type has little to no competition for resources and can overgrow, causing disease.
E) The person's immune system is severely suppressed when they are on antibiotics. This means that the Candida is able to colonize areas normally protected by phagocytes, and can thrive there, causing disease.

Question 49

What is NOT a reason why an abscessed wound might not respond to antibiotic treatment?

A) The bacteria within the abscess have stopped replicating, and many antibiotics require actively replicating cells in order to be effective.
B) The blood vessels that would bring the drug to the area have been destroyed or have clots, preventing the drug from getting to the microbes.
C) The chemical composition of the pus in the abscess often inactivates antibiotics, making them ineffective.
D) These are all reasons that it might be difficult to treat an abscess.
E) The bacteria in an abscess always acquire multi-drug antibiotic resistance, so any drugs that are used will have no effect.

Question 50

Individuals who have recovered from tetanus are not immune to the disease and must be immunized.

Question 51

Both Staphylococcus aureus and Streptococcus pyogenes

A) are rod-shaped.
B) have fibronectin-binding proteins.
C) cause necrotizing fasciitis.
D) have exotoxin A.
E) are coagulase positive.

Question 52

Select the True statement regarding staphylococci and staphylococcal wound infections.

A) Staphylococcus aureus forms biofilms but lacks virulence factors and is not very pathogenic.
B) Staphylococcus epidermidis produces several virulence factors, including exotoxins.
C) Both HA-MRSA and CA-MRSA are resistant to multiple antibiotics, including sulfa drugs and tetracyclines.
D) Some S. epidermisis strains produce superantigens that activate many helper T cells, causing a cytokine storm.
E) S. aureus and S. epidermidis are both coagulase-positive, encapsulated organisms.

Question 53

Would babies need to be immunized against lockjaw (tetanus) if their mother had been immunized against the disease?  Why or why not?

A) No, because the mother's IgG antibodies would be passed along through the placenta before birth, protecting the baby from the infection.
B) Yes, because even though maternal IgG antibodies might be passed along through the placenta, they will not last forever. The baby will need to create its own antibody response to be protected against future tetanus.
C) No, because maternal IgG antibodies would be passed along in the breast milk, protecting the baby from infection.
D) Yes, because the maternal response to the tetanus vaccine is to produce IgE antibodies, and IgD antibodies are the predominant type in breast milk. Therefore, even if the baby is breast-fed, it won't receive the mother's protective antibodies.
E) Yes, because although the mother will make IgG antibodies in response to the vaccine, these antibodies cannot cross the placenta, so the baby is not protected at all.

Question 54

Staphylococci are the leading cause of wound infections.

Question 55

All staphylococci are coagulase positive.

Question 56

How is Staphylococcus aureus distinguished from Staphylococcus epidermidis?

A) It is Gram-positive.
B) It is spherical in shape.
C) It is an opportunistic pathogen.
D) S. aureus produces coagulase.
E) It does not produce coagulase.

Question 57

Rowley Pharmaceutical company produces a drug that promotes new blood vessel growth. Is there any application for this drug in wound treatment?

A) It could be very beneficial. One of the biggest problems with wound infections is that they are anaerobic, because the blood supply to the area is usually compromised. Certain pathogenic microbes then thrive in this environment, creating very serious wound infections.
B) It would not be beneficial. Part of the reason abscesses lack blood flow is to keep bacteria from spreading to other areas of the body. Increasing blood flow to the area will provide a way for these bacteria to infect other organ systems.
C) It could be dangerous. Wounds need to cut off blood supply to prevent the patient from bleeding to death. Increasing blood vessel development in the wound site might cause the patient to bleed out.
D) There would be no beneficial effect. The immune response is already in place in the wound site, so increasing blood cell delivery to the area wouldn't increase or decrease the rate of wound healing.
E) It would be dangerous. New blood vessels would reduce the anaerobic nature of the wound but it would also always result in massive edema which may lead to permanent loss of function.

Question 58

Both Staphylococcus aureus and Streptococcus pyogenes have fibronectin-binding proteins.

Question 59

"Flesh-eating" Streptococcus pyogenes is considered a newly emerging disease.

Question 60

An abscess is a collection of pus.

Question 61

Why is Staphylococcus epidermidis able to colonize plastic materials used in medical procedures?

A) It has fimbriae that allow it to attach to plastic surfaces.
B) It can bind to fibronectin, a blood protein that coats plastic implants.
C) It produces coagulase that allows it to colonize inert surfaces such as titanium.
D) It can produce a glycocalyx that allows it to form biofilms.
E) These are all factors that allow S. epidermidis to colonize implants.

Question 62

Bite wounds are often serious as they may lead to an infection in which two or more species of pathogens act together to produce an effect greater than the sum of effects if each pathogen were acting alone. This is referred to as a(n) ________ infection.

A) mutualistic
B) parasitic
C) fasciltatory
D) complicated
E) synergistic

Question 63

Which of the following help(s) S. pyogenes evade the immune system?

A) Hyaluronic acid capsule
B) M protein
C) G protein
D) G protein AND hyaluronic acid capsule 
E) M protein AND hyaluronic acid capsule 

Question 64

Which of the following best describes the causative agent of necrotizing fasciitis?

A) β-hemolytic, Gram-negative, spore-forming, obligate anaerobe
B) β-hemolytic, Gram-positive, chain-forming, aerotolerant anaerobe
C) Encapsulated, Gram-negative, chain-forming, facultative aerobe
D) Encapsulated, Gram-negative, spore-forming, facultative aerobe
E) Encapsulated, acid-fast, chain-forming, facultative anaerobe

Question 65

Antibiotics are given to a person with gas gangrene to

A) improve oxygenation in the affected tissues.
B) prevent additional toxin production.
C) stop bacterial growth AND neutralize α-toxin.
D) stop bacterial growth AND prevent additional toxin production.
E) neutralize α-toxin AND improve oxygenation in the affected tissues.

Question 66

Why are signs and symptoms not quickly resolved in a person with tetanus when they are given antibiotics? 

A) Clostridium tetani is an acid-fast organism; it thus has a waxy cell wall that prevents antibiotics from entering the cell.
B) Antibiotics will prevent the production of additional tetanospasmin but will not repair nerves already damaged by the toxin.
C) The antibiotics are given prophylactically, to prevent secondary infections. Nerves damaged by tetanospasmin need time to repair.
D) Clostridium tetani is resistant to most antibiotics; treatment thus involves several weeks of combined antibiotic therapy.
E) Clostridium tetani is an acid-fast organism; it thus has a slow generation time, so it takes several weeks for an antibiotic to be effective in killing the cells.

Question 67

Select the True statement regarding clostridial myonecrosis.

A) Clostridium perfringens infects healthy tissue and grows easily in well oxygenated tissues.
B) The causative agent produces α-toxin, an A-B toxin that destroys lecithin in host cell membranes, leading to cell lysis.
C) Hyperbaric chambers may be used to treat patients with gangrene-high levels of O₂ reduce anaerobic conditions in the tissues.
D) Prevention of clostridial myonecrosis can be achieved with the DCTaP vaccine.
E) C. perfringens is an endospore-forming organism, and produces large number of spores in wounds or cultures.

Question 68

Which characteristic(s) is/are NOT common to C. tetani and C. perfringens?

A) They are obligate anaerobes.
B) They are spore-formers.
C) They are Gram-positive bacteria.
D) They produce A-B toxins.
E) They are rod-shaped.

Question 69

A patient presents with a wound that contains green pus. This suggests to you that the wound is infected with

A) S. epidermidis, which produces the water-soluble pigments pyoverdin and pyocyanin.
B) S. pyogenes, which produces a water-soluble blue-green capsule.
C) P. aeruginosa, which multiplies in photosynthetic biofilms that are green.
D) P. aeruginosa, which produces the water-soluble pigments pyoverdin and pyocyanin.
E) either S. epidermidis or S. aureus, both of which produce pigment soluble coagulase.

Question 70

Which virulence factor of P. aeruginosa inhibits host cell protein synthesis?

A) Exotoxin A
B) Exoenzyme S
C) Phospholipase C
D) Pyoverdin
E) Pyocyanin

Question 71

Why is it difficult to treat P. aeruginosa wound infections?

A) The organism is resistant to multiple different antibiotics.
B) P. aeruginosa forms biofilms, which protect the bacteria.
C) The organism is resistant to multiple different antibiotics AND P. aeruginosa forms biofilms, which protect the bacteria.
D) The organism is resistant to multiple different antibiotics AND P. aeruginosa forms endospores which are extremely hardy and difficult to destroy.
E) P. aeruginosa forms endospores which are extremely hardy and difficult to destroy.

Question 72

It is possible to cultivate Clostridium tetani from a wound, even if the affected person does not have tetanus. How can this be explained?

A) If Clostridium tetani is cultured from a wound, the person MUST have tetanus. However, in some people the signs and symptoms of tetanus are extremely mild, so it can be difficult to detect the disease in them.
B) Clostridium tetani may be growing vigorously in the wound. However, the organism only produces tetanospasmin if the person's immune system is compromised, so a healthy person may not develop the disease.
C) The wound may contain spores that can be germinated under appropriate conditions in culture. However, they will not germinate in a wound unless it is anaerobic. Since the spores themselves do not produce toxin, their presence does not lead to tetanus.
D) Clostridium tetani is part of the normal microbiota of the integumentary, cardiovascular, and lymphatic systems. It makes sense that it would be possible to culture the organism from a wound, even in a healthy person.
E)  None of these adequately explains how C. tetani can be cultured from the wound of a healthy person.

Question 73

Why is debridement and/or amputation often needed to treat necrotizing fascitiis?

A) These procedures remove the toxins released by the causative organisms.
B) These procedures remove infected tissue and thus the source of damaging bacterial toxins.
C) S. pyogenes multiplies in dead tissue, using the breakdown products as nutrients.
D) These procedures remove infected tissue and thus the source of damaging bacterial toxins AND the procedures remove the source of nutrients for multiplying bacteria.
E) These procedures remove the source of nutrients for multiplying bacteria AND these procedures prevent the causative agent from releasing damaging toxins and enzymes.

Question 74

Choose one False statement about the treatment of clostridial myonecrosis.

A) Placing a person with gangrene in a hyperbaric chamber always eliminates the need for debridement and/or amputation.
B) High doses of antibiotics, often a combination of penicillin and clindamycin, are given to help stop bacterial growth and toxin production.
C) Prompt debridement of all dead and infected tissues is essential; in some cases amputation is also necessary.
D) Antibiotic treatment of clostridial myonecrosis is challenging because antibiotics do not diffuse well into necrotic tissue.
E) Antibiotic treatment of clostridial myonecrosis stops bacterial growth but has no impact on any toxin already produced by the causative agent.  

Question 75

Which statement regarding the pathogenesis of necrotizing fasciitis is INCORRECT?

A) The causative agent produces SPE A, a superantigen that causes helper T cells to release large amounts of cytokines, leading to toxic shock.
B) SPE B is a protease produced by S. pyogenes that causes tissue death and breakdown, leading to fluid accumulation in the area and intense swelling.
C) A hyaluronic acid capsule and M protein allow the causative agent to evade the immune responses.
D) M protein-fibrinogen complexes causes neutrophils to release inflammatory molecules that increase vascular permeability and lead to a blood pressure drop.
E) The causative agent sheds antibodies that attach to fibrinogen and recruit natural killer cells that destroy muscle fascia through ADCC.

Question 76

Which statement regarding the treatment of tetanus is False?

A) TIG antibodies bind to circulating toxin molecules, neutralizing their effects and providing passive immunity.
B) TIG neutralizes tetanospasmin that is already attached to nerve tissue, preventing damage to that nerve.
C) An antibacterial medication such as metronidazole is given to kill any actively multiplying bacterial cells.
D) The patient is given muscle relaxants and supportive care, including being placed on a ventilator if needed.
E) The person is given tetanus vaccine that results in the production of anti-tetanospasmin antibodies.

Question 77

How is it possible for anaerobes to be involved in bite wound infections?

A) Most bite wounds are on hands or fingers, which have little tissue and few blood vessels, and are thus fairly anaerobic.
B) Facultative anaerobes in bite wounds reduce available oxygen in the affected tissue, creating anaerobic conditions.
C) Bite wounds result in the release of anaerobinases by keratinocytes; these convert oxygen to nitrogen, generating anaerobic conditions.
D) Although anaerobes are introduced into a wound through biting, they do not multiply in the aerobic tissue and do not contribute to a bite wound infection.
E) In fact, anaerobes are never involved in bite wound infections; tissues are always well oxygenated, which inhibits any anaerobes from multiplying in them.

Question 78

Choose the one False statement about Pseudomonas aeruginosa.

A) It is widespread in nature, commonly found in plants.
B) Some strains can grow in nutrient-poor environments, including distilled water.
C) It secretes pigments that together produce a green color.
D) Under certain circumstances, it can grow anaerobically.
E) It is a Gram-positive, spore-forming encapsulated rod.

Question 79

How may lung damage or pneumonia occur in a person with tetanus?

A) Spasms of major chest muscles may be so severe that the lungs are damaged.
B) Tetanospasmin is an A-B toxin that binds to lung epithelial cells, killing them.
C) C. tetani releases alpha-toxin that causes the alveoli of the lungs to collapse.
D) The person may inhale regurgitated (vomited) stomach contents.
E) Tetanospasmin causes the release of degradative enzymes in the lungs.

Question 80

Clostridium tetani is a highly invasive pathogen that causes tetanus, characterized by spastic paralysis.