Chapter 19 Multiple Choice

Which of the following bacteria is a genus of high G + C Gram-positive bacteria?

A) Staphylococcus

B) Streptococcus

C) Bacillus

D) Mycobacterium

E) Listeria

Which of the following has been historically classified as Gram-negative bacteria but is genetically more similar to low G + C Gram-positive bacteria?

A) mycoplasmas

B) Mycobacterium

C) Clostridium

D) Propionibacterium

E) Nocardia

What is one feature that differentiates Staphylococcus aureus from other species of staphylococci?

A) It has a slime layer capsule.

B) It can produce coagulase.

C) It can produce hyaluronidase.

D) It can live on the surface of the skin and in cutaneous oil glands.

E) It produces exfoliative toxins.

Over 90% of Staphylococcus aureus bacteria can withstand the effect of penicillin. Why?

A) They have loosely organized polysaccharide slime layers.

B) They produce coagulase.

C) Cell division occurs in successively different planes, and the daughter cells remain attached to one another.

D) They produce !-lactamase.

E) They produce staphylokinase, which dissolves fibrin threads in blood clots.

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) Enterococcus.

B) Staphylococcus epidermidis.

C) Staphylococcus aureus.

D) methicillin-resistant Staphylococcus aureus (MRSA).

E) Streptococcus pyogenes (group A streptococcus).

Streptococcus agalactiae is associated with which of the following diseases?

A) neonatal bacteremia

B) neonatal meningitis

C) neonatal pneumonia

D) neonatal bacteremia and neonatal meningitis

E) neonatal bacteremia, neonatal meningitis, and neonatal pneumonia

Which of the following statements regarding Streptococcus pyogenes is FALSE?

A) It produces protein A, which inhibits opsonization.

B) It is beta-hemolytic.

C) It has group A Lancefield antigens.

D) It produces streptolysins.

E) It can be lysogenized by a temperate bacteriophage to produce erythrogenic

What differentiates virulent strains of Streptococcus pneumoniae from nonvirulent strains?

A) the species-specific teichoic acid present in its cell wall

B) the type of Lancefield antigen it produces

C) the presence of a polysaccharide capsule that protects it from digestion after endocytosis D) the type of toxins it produces

E) the extent of the hemolytic zone it produces when it is grown on blood agar

The Quellung reaction is used to diagnose

A) Staphylococcus aureus.

B) Streptococcus pyogenes.

C) Streptococcus agalactiae.

D) Streptococcus pneumoniae.

E) Streptococcus equisimilis.

Otitis media may lead to dangerous meningitis in children due to infection with

A) Streptococcus agalactiae.

B) Streptococcus pneumoniae.

C) Streptococcus mutans.

D) Enterococcus.

E) Mycoplasma pneumoniae.

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) Enterococcus.

B) Mycoplasma.

C) Staphylococcus.

D) Streptococcus.

E) Listeria.

Which of the following streptococci is associated with dental caries?

A) viridans streptococci

B) Streptococcus pyogenes

C) Streptococcus pneumoniae

D) Streptococcus equisimilis

E) Streptococcus arginosus

Which of the following statements about Bacillus anthracis is FALSE?

A) It is primarily a disease of humans.

B) It produces endospores.

C) It has a capsule.

D) It normally dwells in the soil and can survive in the environment for centuries or longer. E) It can be lethal even after treatment because antimicrobial drugs do not inactivate accumulated anthrax toxin.

Which of the following bacteria produce one of the most deadly bacterial toxins known? A) Clostridium perfringens

B) Clostridium difficile

C) Clostridium tetani

D) Clostridium botulinum

E) Corynebacterium species

Which of the following bacteria can cause life-threatening pseudomembranous colitis? A) Clostridium difficile

B) Staphylococcus aureus

C) Streptococcus pyogenes

D) Enterococcus species

E) Clostridium botulinum

How does the toxin from Clostridium tetani produce its action?

A) It fuses irreversibly to neuronal cytoplasmic membranes, blocking release of acetylcholine at synaptic clefts.

B) The smaller polypeptide of its toxin can block the release of inhibitory neurotransmitters by inhibitory neurons in the central nervous system, causing simultaneous contraction of both muscles in an antagonistic pair.

C) It is a pyrogenic toxin, which triggers a diffused rash and, later, sloughing of skin. D) It destroys tissues, including muscle and fat.

E) It produces antibodies that attack the neuromuscular junctions in skeletal muscle and prevent them from relaxing.

Listeria's virulence is directly related to its ability to

A) produce powerful toxins.

B) form very resistant endospores.

C) live within cells and thus avoid exposure to the immune system of its host.

D) easily become a pathogen in humans.

E) resist most antimicrobial agents.

Which of the following bacteria divide by "snapping division" in which daughter cells remain attached in characteristic V-shapes?

A) staphylococci

B) enterococci

C) Corynebacterium

D) Listeria

E) Mycobacterium

Which of the following statements about diphtheria is FALSE?

A) Although all species of Corynebacterium are pathogenic, the agent of diphtheria is the most widely known.

B) Its toxin destroys elongation factor, which is needed to synthesize polypeptides in eukaryotes.

C) It produces a characteristic pseudomembrane that can adhere to the tonsils, uvula, palate, pharynx, and larynx.

D) Its growth on Loffler's medium is used for absolute diagnosis of the bacterium.

E) Its toxin can be absorbed into the blood from cutaneous lesions and can lead to cardiac arrhythmia, coma, and death.

Mycoplasma pneumoniae is distinguished from other members of the genus

A) because it is strictly aerobic.

B) because it is a facultative anaerobe.

C) by its lack of cytochromes.

D) by the presence of sterols in its cytoplasmic membrane.

E) by the presence of a rudimentary cell wall.

A sample of fluid from the lungs contains microbes that grow in filaments, and the filaments tend to align with one another. The cells stain poorly in the Gram stain and are a pink-red when acid-fast stained. The bacteria in the sample are

A) Mycobacterium species.

B) Mycoplasma species.

C) Nocardia species.

D) Actinomyces species.

E) not identifiable with this information.

Which of the following bacteria cause Hansen's disease?

A) Mycobacterium tuberculosis

B) Mycobacterium leprae

C) Clostridium difficile

D) Listeria species

E) Corynebacterium species

The pus from an abscess in a patient's jaw contains microbes that form yellowish grainy masses and appear filamentous under the microscope. Neither antifungal medication nor a normal course of antibiotics has been effective in treating the infection. The abscess is likely the result of infection with

A) Actinomyces.

B) Mycobacterium.

C) Nocardia.

D) Propionibacterium.

E) Streptococcus.

What is the most common disease caused by Propionibacterium?

A) acne

B) food poisoning

C) pneumonitis

D) folliculitis

E) a sty

Mycetoma, which is a painless long-lasting infection characterized by swelling, pus production, and draining sores, is caused by

A) systemic tuberculosis.

B) Nocardia.

C) Actinomyces.

D) penicillin-resistant staphylococci.

E) cutaneous anthrax.