Exam 3 Flashcards
Endotoxins are also known as
Lipid A.
When would endotoxins be released from a bacterial cell?
When the cell dies
Which of the following would be the first sign of an infection that resulted in the release of endotoxin?
Fever
Why is a release of endotoxin into the bloodstream potentially deadly?
It can lower blood pressure and cause the patient to go into shock.
An exotoxin that has the ability to kill or damage host cells is referred to as a(n)
cytotoxin.
Which domain of the A-B toxin binds to cell surface receptors on the host cell?
B domain
How are superantigens different from other types of exotoxins?
Superantigens cause an overstimulation of the host immune system.
A person who attended a picnic early in the day develops a very high fever and is unresponsive by the evening. This person most likely has been exposed to a(n)
superantigen
A patient who has been hospitalized with uncontrolled muscle spasms has probably been infected with bacteria that secrete a(n)
neurotoxin
In mice, the LD50 for staphylococcal enterotoxin is 1350 ng/kg, and the LD50 for Shiga toxin is 250 ng/kg. Which of the following statements is true?
Shiga toxin is more lethal than staphylococcal enterotoxin.
Which of the following would be an example of an infection initiated via the parenteral route?
An individual contracts hepatitis B from an accidental stick with a contaminated needle.
Which of the following statements about adherence is true?
Most bacterial adhesins are glycoproteins or lipoproteins.
Which disease would be potentially propagated in an environment without functional plumbing and in which drinking water is contaminated with sewage?
cholera
Which type of bacterial enzyme helps spread Streptococcus pyogenes by digesting blood clots?
fibrinolysin
Which of the following features of Salmonella prevent it from being phagocytosed?
Flagella
Where do Salmonella pathogens grow and replicate in the infected host?
Inside phagocytes
Where is the site of Shigella attachment in the host?
M cells
How do Shigella cells move between host cells?
They can polymerize actin molecules from the epithelial cells into tail-like structures that propel them from one cell to another.
What is the etiologic agent of typhoid?
Salmonella
How are immune cells able to detect foreign pathogens?
They are able to detect structures on the surfaces of foreign cells that are not found in the host.
How does a capsule help certain bacteria evade detection by the immune system?
The capsule is composed of polysaccharides that are similar to those found in the host; thus, the immune system does not recognize it as foreign.
Which of the following microorganisms actually grows inside the macrophage?
Tuberculosis bacterium
How does the protozoan Trypanosoma evade detection by the immune system?
It can change the surface antigens frequently, preventing the immune system from tracking it.
Certain traits that allow pathogens to create infection and cause disease are termed
virulence factors.