Bio2260k Test 4 Textbook Review

The accompanying graph plots guanine plus cytosine content across the genome of a bacterial pathogen whose overall GC content is 50%. Which of the following chromosome segments could represent a pathogenicity island?

Segments A and C

Which of the following mechanisms contributes directly to pathogen evolution?

Conjugation

Which of the following statements is true?

DNA sequences flanking pathogenicity islands are often remnants of HGT mechanisms

Chronic infections are usually associated with _____

biofilm-producing bacteria

Bordetella pertactin is an example of a(n) _____

nonpilus adhesin

Pilus contact between a pathogen and a host cell _____

prevents evacuation of the pathogen

Salmonella enterica serovar Typhimurium, while causing an infection, _____

remains in a Salmonella-containing host cell vacuole

Which one of the following bacteria is an obligate intracellular pathogen?

Rickettsia

During infection, Listeria monocytogenes _____

moves intracellularly via actin tails

Which of the following toxins ADP-ribosylates a G-factor?

Escherichia coli LT

Which of the following toxins stimulates cytokine production through a superantigen mechanism?

Toxic shock syndrome toxin

Type III secretion systems are paralogous to _____

flagellum synthesis systems

Which of the following best explains why one person can develop multiple colds over a lifetime?

Multiple rhinovirus strains that possess different VP1 structures

Cytomegalovirus, which can cause a mononucleosis-type disease, prevents the immune system from destroying infected cells by _____

placing a molecular mimic of MHC I on an infected cell’s surface

Which of the following virulence mechanisms does influenza virus use?

NS1 protein to inhibit production of interferon

What percentage of the world’s population is thought to be infected with Toxoplasma gondii?

50%

By which of the following actions do Leishmania protozoa avoid the immune system?

Down-regulate IL-12 production in infected macrophages

Which of the following organisms is a nondimorphic pathogenic fungus?

Aspergillus fumigatus