Mastering Chapter 19

A patient presents with a severe skin infection characterized by lesions that are swollen, draining sores. You learn that the patient is an avid gardener. Which of the following diseases should be suspected? A. erysipelas B. mycetoma C. Hansen's disease D. tetanus

B. mycetoma

It is estimated that _____ of the world's population may be infected with tuberculosis. A. 75% B. 33% C. 1% D. 5%

B. 33%

Which of the following habits will best prevent infection due to listerosis? A. Wash your hands after handling pet feces. B. Avoid eating raw fruits and vegetables C. Avoid eating or drinking pasteurized dairy products. D. Avoid hard cheeses, such as cheddar.

B. Avoid eating raw fruits and vegetables

Which of the following bacteria can cause life-threatening pseudomembranous colitis? A. Clostridium botulinum B. Clostridium difficile C. Staphylococcus aureus D. Streptococcus pyogenes E. Enterococcus species

B. Clostridium difficile

What is empyema? A. Septicemia refers to a pocket of pus in between the lung and the inner surface of the chest wall. B. Empyema refers to a pocket of pus in between the lung and the inner surface of the chest wall. C. Empyema refers to air in the pleural cavity. D. Empyema refers to blood in the pleural cavity.

B. Empyema refers to a pocket of pus in between the lung and the inner surface of the chest wall.

The presence of ________ can be used to distinguish Staphylococcus from other Gram-positive cocci. A. enterotoxins B. protein M C. catalase enzyme D. hemolysins E. kinases

C. catalase enzyme

A characteristic symptom of necrotizing fasciitis is that the pain __________. A. occurs only during nighttime hours B. is disproportionate to the appearance of the infection C. comes across as a cold sensation D. is almost insensible

B. is disproportionate to the appearance of the infection

The skin lesions characteristic of cutaneous infections with Bacillus anthracis are A. scarlatina. B. pus-filled ulcers. C. eschars. D. impetigo.acne.

C. eschars.

Bacteria collected from a severely inflamed wound are sent to the lab for analysis. The results come back as follows: Gram-positive cocci in irregular clusters, kinase and coagulase positive, and able to grow in the presence of most antibiotics except vancomycin. The bacteria in the wound are most likely A. Staphylococcus epidermidis. B. Staphylococcus aureus. C. methicillin-resistant Staphylococcus aureus (MRSA). D. Enterococcus. E. Streptococcus pyogenes (group A streptococcus).

C. methicillin-resistant Staphylococcus aureus (MRSA).

A strain of Staphylococcus aureus that loses the ability to produce staphylokinase will be unable to do which of the following? A. degrade beta-lactam antibiotics B. grow on the surface of the skin C. spread to new locations in the body D. evade immune cells

C. spread to new locations in the body

Which of the following is a key diagnostic indicator of infection with Mycobacterium leprae? A. blister-like lesions B. localized loss of the sense of touch C. a distinctive red rash that lasts for days D. pus-filled abscesses E. severe inflammation with swelling

B. localized loss of the sense of touch

The most significant streptococcal pathogens are found in which of the following Lancefield groups? A. groups A, B, and D B. groups B and D C. groups A and D D. groups A and B

D. groups A and B

Which of the following would be diagnostic for the presence of Corynebacterium diphtheriae in a clinical specimen? A. "tumbling" motility at room temperature B. pleomorphic bacteria in palisade formations C. "fried egg" appearance in cultures C. dull, yellow raised colonies on Lowenstein-Jensen agar

B. pleomorphic bacteria in palisade formations

One of the primary reasons the disease is able to evade the body's immunity is that it __________. A. is camouflaged in hyaluronic acid B. resists digestion by phagocytes C. hides within host epithelial cells D. produces a capsule

B. resists digestion by phagocytes

Which of the following diseases is considered an autoimmune disease triggered by bacterial infection? A. impetigo B. rheumatic fever C. scarlet fever D. glomerulonephritis caused by the group A streptococci E. toxic shock syndrome

B. rheumatic fever

In approximately 10% of patients tubercles rupture and reactivate infection. This is known as _____ tuberculosis. A. primary B. secondary C. tertiary D. disseminated

B. secondary

Members of the genus Mycoplasma are pleomorphic and stain Gram-negative because they A. have sterols in their cytoplasmic membranes. B. have mycolic acid in their cell walls. C. have a rudimentary cell wall. D. lack cytoplasmic membranes. E. lack cell walls.

E. lack cell walls.

Streptococcus agalactiae is associated with which of the following diseases? A. neonatal meningitis B. neonatal pneumonia C. neonatal bacteremia D. both neonatal bacteremia and neonatal meningitis E. neonatal bacteremia, neonatal meningitis, and neonatal pneumonia

E. neonatal bacteremia, neonatal meningitis, and neonatal pneumonia

Untreated streptococcal pharyngitis may progress to A. scarlet fever or necrotizing fasciitis. B. rheumatic fever. C. scarlet fever. D. necrotizing fasciitis. E. scarlet fever or rheumatic fever.

E. scarlet fever or rheumatic fever.

Over 90% of Staphylococcus aureus isolates are penicillin-resistant. Why? A. they produce staphylokinase. B. they produce coagulase. C. they have loosely organized polysaccharide slime layers which protects their cell wall. D. They have a coating of protein A. E. they produce β-lactamase.

E. they produce β-lactamase.

The bacterium Streptococcus mutans has a major role in the development of dental plaque and caries. True False

True

The neurotoxins of Clostridium botulinum produce (flaccid/tetanic) paralysis by preventing muscle contraction.

flaccid

Staphylococcus aureus food poisoning is long-lasting because ingested bacteria produce enterotoxins in the digestive system. True False

False

Adult foodborne botulism can be prevented by thoroughly cooking food (minimum 80°C for 20 minutes) before it is eaten. True False

True

All of the following methods of food storage or preparation except which of the following can help prevent foodborne botulism? A. storing canned foods at room temperature B. storing canned foods in the refrigerator C. heating canned foods to at least 80 degrees Celsius for 20 minutes before consuming D. maintaining an acidic environment below ph 4.5

A. storing canned foods at room temperature

One of the virulence factors produced by Group A Streptococcus is __________, which can kill neutrophils, the immune system's first responders. A. streptolysin S B. exotoxin A C. Streptokinase D. Hyaluronidase

A. streptolysin S

Which of the following staphylococcal virulence factors produce the signs and symptoms of scalded skin syndrome? A. exfoliative toxin B. hyaluronidase C. leukocidin D. staphylokinase E. coagulase

A. exfoliative toxin

Which of the following streptococci is associated with dental caries? A. viridans streptococci B. Streptococcus pyogenes C. Streptococcus arginosus D. Streptococcus equisimilis E. Streptococcus pneumoniae

A. viridans streptococci

To diagnose meningitis due to Listeria infection, physicians will first examine a patient's ___. A. cerebrospinal fluid B. blood C. gall bladder D. fecal samples

A. cerebrospinal fluid

Lance's physician administered a tuberculin test to determine whether Lance had been infected during his flight from South Africa. How was this test performed? A. A small amount of cell wall material from Mycobacterium tuberculosis was injected into Lance's forearm skin. B. Lance's blood was drawn and examined for the presence of Mycobacterium tuberculosis. C. A sputum specimen from Lance was cultured for possible growth of Mycobacterium tuberculosis. D. An X-ray film of Lance's lungs was taken.

A. A small amount of cell wall material from Mycobacterium tuberculosis was injected into Lance's forearm skin.

What is the name of the vaccine given to prevent TB in countries where it is endemic? A. BCG vaccine B. RTS vaccine C. Pneumovax vaccine D. DTaP vaccine

A. BCG vaccine

Based on its Gram status, why are penicillin and other beta-lactam antibiotics effective against Streptococcus pneumoniae? A. Beta lactam antibiotics are effective against Streptococcus pneumoniae because it is a Gram positive organism and does not have an outer membrane. B. Beta lactam antibiotics are effective against Streptococcus pneumoniae because it is a Gram positive organism and has an outer membrane. C. Beta lactam antibiotics are effective against Streptococcus pneumoniae because it is a Gram negative organism and does not have an outer membrane. D. Beta lactam antibiotics are effective against Streptococcus pneumoniae because it is a Gram negative organism and has an outer membrane.

A. Beta lactam antibiotics are effective against Streptococcus pneumoniae because it is a Gram positive organism and does not have an outer membrane.

How might an infected patient transmit listeriosis to another human? A. During pregnancy. B. Aerosolized droplets in a cough. C. Fecal-oral route. D. Through sexual contact.

A. During pregnancy.

What is the best way to prevent nosocomial MRSA infections? A. Everyone should wash their hands before eating and after contact with any potentially contaminated surface/person. B. All hospitalized patients should take antibiotics daily. C. All hospitalized patients should wear a surgical mask D. People should be vaccinated with the MRSA vaccine.

A. Everyone should wash their hands before eating and after contact with any potentially contaminated surface/person.

Streptococcus pneumoniae is found as part of the normal microbiota of the mouth and pharynx and yet can cause disease in some people when it is inhaled into lungs. Why do you think this is? A. If Streptococcus pneumoniae is inhaled from the nasopharynx into lungs damaged by a previous viral infection or in an immune compromised person, it can flourish. B. If Streptococcus pneumoniae is inhaled deeply enough into the lungs, there are receptors present to which the bacteria can adhere. C. There is less immune system surveillance in the lungs compared to the nasopharynx. D. The environment in the lungs is more favorable for Streptococcus pneumoniae than the nasopharynx.

A. If Streptococcus pneumoniae is inhaled from the nasopharynx into lungs damaged by a previous viral infection or in an immune compromised person, it can flourish.

What is one virulence factor that differentiates Staphylococcus aureus from other species of staphylococci? A. It can produce coagulase. B. It has a capsule. C. It produces catalase. D. it can live on the surface of the skin and in cutaneous oil glands. E. it produces lipase.

A. It can produce coagulase.

__________ is an antiphagocytic factor and helps S. pyogenes attach to nose and throat cells. A. M protein B. Streptolysin C. Hyaluronidase D. Deoxyribonuclease

A. M protein

Are Clostridium botulinum vegetative cells required to be present for foodborne botulism to occur? A. No, foodborne botulism is caused by the botulinum toxin produced by the bacteria, not the bacteria themselves. B. Yes, the foodborne botulism is caused by endotoxic shock, which occurs when the cell walls of Clostridium botulinum are disrupted. C. No, foodborne botulism is caused by the endospore form of Clostridium botulinum, not vegetative cells. D. Yes, the foodborne botulism can only be caused by infection with Clostridium botulinum vegetative cells.

A. No, foodborne botulism is caused by the botulinum toxin produced by the bacteria, not the bacteria themselves.

Why does tuberculosis involve months of antibiotic treatment? A. The bacteria grow very slowly. B. The bacteria become resistant to the medications after only a month of treatment. C. The bacteria go into a dormant state. D. The antibiotic treatment is so toxic, it can only be given in very small doses.

A. The bacteria grow very slowly.

Mycobacterium tuberculosis is considered a(n) __________. A. aerobe B. facultative anaerobe C. anaerobe D. microaerophile

A. aerobe

The pneumococcal vaccine was made using the purified capsular material from 23 common strains of Streptococcus pneumoniae, but it is not effective against all strains. Why is this? A. It cannot cover all the strains of Streptococcus pneumoniae because not all strains have the same type of cell wall. B. It cannot cover all the strains of Streptococcus pneumoniae because not all strains have the same antigens on their surface. C. If a person is infected with a strain other than the 23 used to make the vaccine, it may not be recognized by neutrophils. D. If a person is infected with a strain other than the 23 used to make the vaccine, it may not be recognized by the natural killer (NK) cells of the immune system.

B. It cannot cover all the strains of Streptococcus pneumoniae because not all strains have the same antigens on their surface.

Which of the following lists the criteria for a diagnosis of Staphylococcus aureus infection? A. Staphylococcus aureus cultures are coagulase positive, catalase negative, translucent colonies that are composed of Gram-positive cocci. B. Staphylococcus aureus cultures are coagulase positive, catalase positive, yellow colonies that are composed of Gram-positive cocci. C. Staphylococcus aureus cultures are coagulase negative, catalase positive, white colonies that are composed of Gram-positive cocci. D. Staphylococcus aureus cultures are coagulase positive, catalase positive, yellow colonies that are composed of Gram-positive bacilli.

B. Staphylococcus aureus cultures are coagulase positive, catalase positive, yellow colonies that are composed of Gram-positive cocci.

Which of the following bacteria is the primary cause of necrotizing fasciitis? A. Clostridium perfringens B. Streptococcus pyogenes C. Staphylococcus aureus D. Bacterioides fragilis

B. Streptococcus pyogenes

Streptococcus pneumoniae was originally named Diplococcus pneumoniae. Why was the genus name Diplococcus originally given to this organism? A. The prefix di- means "four", and on agar plates, the colonies are found in groups of four. B. The prefix di- means "two", and these organisms are usually found in pairs under the microscope. C. The prefix di- means "two", and on agar plates, the colonies are found in groups of two. D. The prefix di- means "four", and these organisms are usually found in groups of four under the microscope.

B. The prefix di- means "two", and these organisms are usually found in pairs under the microscope.

An appropriately stained smear was prepared of a sputum specimen obtained from the sick woman on Lance's flight. Using oil-immersion magnification on your microscope, what would you observe that would aid in the diagnosis of tuberculosis? A. Gram-positive cocci B. acid-fast rods C. acid-fast cocci D. Gram-positive rods

B. acid-fast rods

How is tuberculosis transmitted? A. fecal/oral route B. aerosol droplets released by a cough or sneeze C. sharing "dirty" needles between IV drug users D. drinking pasteurized milk

B. aerosol droplets released by a cough or sneeze

Mycoplasma pneumoniae causes respiratory disease by A. paralyzing the respiratory muscles. B. attaching to and ultimately killing the ciliated epithelial cells of the trachea. C. triggering inflammatory mediator release. D. killing the epithelial cells of the alveoli. E. infecting and killing alveolar macrophages.

B. attaching to and ultimately killing the ciliated epithelial cells of the trachea.

In which of the following cases would you suspect wound botulism? A. A person injures herself with a sharp knife while cutting vegetables for dinner. Her wound becomes inflamed and warm to the touch and about four days later she develops a fever and chills. B. A person injures herself in a minor car accident. Within two days she develops redness, swelling, and pus at the injury site. C. A person injures herself while gardening. Four days later she begins to feel weak and dizzy, with blurred vision and progressive paralysis. D. A person injures herself by stepping on a rusty garden tool while gardening. Within a week, her jaw and neck muscles begin to tighen and she begins to sweat profusely.

C. A person injures herself while gardening. Four days later she begins to feel weak and dizzy, with blurred vision and progressive paralysis.

What is listeriolysin O? A. A protein that binds to actin filaments. B. An enzyme that destroys the cell membrane, leading to cell death. C. An enzyme breaks the bacteria free from the phagosome. D. A toxin that paralyzes cell activity.

C. An enzyme breaks the bacteria free from the phagosome.

How does ββ-lactamase contribute to the virulence of Staphylococcus spp.? A. ββ-lactamase destroys neutrophils. B. ββ-lactamase breaks down hyaluronic acid in the matrix between cells. C. ββ-lactamase breaks down penicillin and cephalosporin. D. ββ-lactamase triggers blood clot formation.

C. ββ-lactamase breaks down penicillin and cephalosporin.

Why are antimicrobial drugs of limited usefulness in Bacillus anthracis infections? A. B. anthracis grows so slowly that it is hard to kill using antimicrobial drugs. B. Most strains of B. anthracis are resistant to a wide variety of antimicrobial drugs. C. Anthrax toxin is absorbed into the bloodstream very quickly. D. Antimicrobial drugs are unable to neutralize anthrax toxin.

D. Antimicrobial drugs are unable to neutralize anthrax toxin.

How are patients typically infected with listeriosis? A. Inhalation of dust particles B. Eating undercooked chicken C. A tick bite D. Contaminated food or drink

D. Contaminated food or drink

During a stay in the hospital, an accident victim develops symptoms of bacteremia. A blood sample shows the presence of Gram-positive cocci in pairs. Lab tests determine that the bacteria are nonhemolytic and bile salt tolerant. The bacteremia is likely due to A. Mycoplasma. B. Staphylococcus. C. Streptococcus. D. Enterococcus. E. Listeria.

D. Enterococcus.

The BCG vaccine is available to immunize people against tuberculosis. Had Lance been vaccinated, he would not have been concerned about becoming infected on the airplane. Why was he NOT vaccinated? A. The vaccine provides immune protection only for a low percentage of people. B. Use of the vaccine in large populations results in the emergence of drug-resistant strains of Mycobacterium tuberculosis. C. The vaccine requires repeated booster shots because the immune protection is short lived. D. Immunized patients have a positive skin reaction when tested, even if they have not been infected with Mycobacterium tuberculosis. Such "false positive results" hinder the work of epidemiologists trying to track the spread of the disease.

D. Immunized patients have a positive skin reaction when tested, even if they have not been infected with Mycobacterium tuberculosis. Such "false positive results" hinder the work of epidemiologists trying to track the spread of the disease.

Why is necrotizing fasciitis so difficult to prevent? A. It forms endospores and can survive well in the environment. B. Mosquitos are almost impossible to eradicate. C. It is not susceptible to most antibiotics. D. It is part of the normal microbiota.

D. It is part of the normal microbiota.

If ampicillin is the prescribed treatment for listeriosis, why might a physician instead prescribe trimethoprim-sulfamethoxazole? A. Trimethoprim-sulfamethoxazole is a superior antibiotic. B. Listeriosis is often accompanied by a fungal infection. C. Ampicillin further decreases the ability of the immunocompromised to fight infection. D. Patients may be allergic to penicillins.

D. Patients may be allergic to penicillins.

Strains of Streptococcus pneumoniae can cause disease only when a capsule is present. Why is the presence of a capsule considered a virulence factor? A. The capsule prevents the bacterium from releasing chemicals that announce its presence to the host's immune system. B. Streptococcus pneumoniae cannot migrate from the nasopharynx to other areas of the body without a capsule. C. Streptococcus pneumoniae cannot adhere to the cells of the host without a capsule. D. The capsule prevents the bacterium from being digested after endocytosis in the cells of the host.

D. The capsule prevents the bacterium from being digested after endocytosis in the cells of the host.

A patient has a positive tuberculin skin test. Without any other information about the patient, which of the following is the most accurate interpretation of this result? A. The patient has primary tuberculosis. B. The patient has disseminated tuberculosis. C. The patient is able to transmit M. tuberculosis to other individuals. D. The patient has been exposed to M. tuberculosis.

D. The patient has been exposed to M. tuberculosis.

The polymerization of actin filaments allows Listeria to form pseudopods extending from the host cell. How does this aid the bacteria during infection? A. The pseudopods form extracellular vesicles similar to endospores. B. The pseudopods shelter the bacteria from destruction by lysosomes. C. The pseudopods control the movement of the host cells. D. They are able to spread to neighboring cells sheltered from detection by the host immune system.

D. They are able to spread to neighboring cells sheltered from detection by the host immune system.

How do clinicians primarily screen for tuberculosis in patients? A. Throat swab B. Urinalysis C. Blood test D. Tuberculin skin test

D. Tuberculin skin test

Which of the following is an effective way to prevent many staphylococcal infections? A. control of the organism in animals B. proper food canning techniques C. avoiding exposure to soil D. proper cleansing of wounds

D. proper cleansing of wounds

In its role in the development of acne (Propionibacterium/Staphylococcus/Actinomyces) typically grows in sebaceous glands of the skin.

Propionibacterium

The primary treatment for food-borne botulism is (antibiotics/antitoxin/muscle relaxants).

antitoxin