超星 - 球菌--章节练习

单选题

Which of the following cell components produced by Neisseria gonorrhoeae is responsible for attachment to host cells?

A. Lipooligosaccharide
B. Pili (fimbriae)
C. IgA1 protease
D. Outer membrane porin protein
E. Iron-binding protein

单选题

All of the following statements regarding Panton–Valentine leukocidin are correct except

A. It is a two-component toxin
B. It is commonly produced by community-associated MRSA strains
C. It is an important virulence factor
D. It is identical to one of the staphylococcal enterotoxins
E. It forms pores in the membranes of white blood cells

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单选题

All of the following are important infection control strategies in containing spread of MRSA in hospitals except

Aggressive hand hygiene
B. Routine surveillance for nasal colonization among high-risk individuals
Contact isolation for patients who are colonized or infected with MRSA
D. Routine antimicrobial prophylaxis for all patients hospitalized for more than 48 hours
E. Aseptic management of skin lesions

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单选题

Important methods for classifying and separating streptococci are

Agglutination using antisera against the cell wall group-specific substance
Biochemical testing
C. Hemolytic properties (α-, β-, nonhemolytic)
D. Capsular swelling (quellung) reaction
E. All of the above

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单选题

All of the following statements regarding the hyaluronic acid capsule of S. pyogenes are correct except

A. It is responsible for the mucoid appearance of the colonies in vitro
B. It is antiphagocytic
C. It binds to CD44 on human epithelial cells
D. It is an important virulence factor
E. A vaccine against the capsule is currently available

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单选题

All of the following are virulence factors associated with N. gonorrhoeae except

A. Pili
B. Por
C. Lipooligosaccharide
D. Opa proteins
E. A thick polysaccharide capsule

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单选题

Which one of the following microorganisms is closely associated with dental caries?

A. albicans
B. Streptococcus mutans
C. melaninogenica
D. Neisseria subflava
E. epidermidis

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单选题

Reversion ofNeisseria gonorrhoeae from a fimbriated (fim 1) to a non-fimbriated (fim 2) state would result in which one of the following phenomena?

A. Inability of gonorrhoeae to colonize the mucosal epithelium
B. Reversion to a Gram-positive stain
C. Death of the organism
D. Loss of serologic specificity
E. A negative capsule strain

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单选题

A 27-year-old man had a rhinoplasty. A nasal tampon was placed to control the bleeding. Approximately 8 hours later, he developed headache, muscle aches, and abdominal cramps with diarrhea. He then developed an erythematous rash (resembling sunburn) over much of his body, including the palms and soles. His blood pressure is 80/50 mm Hg. The nasal tampon remained in place. His liver enzyme tests were elevated, and there was evidence of moderate renal failure. This patient’s illness was likely to be caused by which of the following?

A. Lipopolysaccharide
B. Peptidoglycan
C. A toxin that is a superantigen
D. A toxin that has A and B subunits
E. Lecithinase (alpha toxin)

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单选题

Bacteria or their components may be characterized by unique constituents or structures. Group A streptococci are characterized by

A. Repeating polysaccharide capsule of glucose and glucuronic acid
B. Outer-membrane proteins
C. γ-Glutamyl polypeptide
D. Sialic acid polymers
E. Hyaluronic acid

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