Ad Blocker Detected
Our website is made possible by displaying online advertisements to our visitors. Please consider supporting us by disabling your ad blocker.
Select the one best response to each question!
All of the following are protective mechanisms against bacteria except
|1. All of the following are protective mechanisms against bacteria except
a. production of fever.
c. activation of complement.
d. alteration of surface antigens.
|2. All of the following are characteristics of streptococcal M proteins except
a. it is the chief virulence factor of group A streptococci.
b. it provokes an immune response.
c. antibodies to one serotype protect against other serotypes.
d. it limits phagocytosis of the organism.
|3. An ASO titer and a Streptozyme test are performed on a patient’s serum. The ASO titer was negative, showing hemolysis in all patient tubes. The Streptozyme test is positive, and both the positive and negative controls react appropriately. What can you conclude from these test
a. The patient has a high titer of ASO.
b. The patient has an antibody to a streptococcal exoenzyme other than streptolysin O.
c. The patient has not had a previous streptococcal infection.
d. The patient has scarlet fever.
|4. Which of the following applies to acute rheumatic fever?
a. Symptoms begin after either a throat or a skin infection.
b. Antibodies to group A streptococci cross-react with heart tissue.
c. Diagnosis is usually made by culture of the organism.
d. All patients suffer permanent disability.
|5. Which of the following indicates the presence of anti-DNase B activity in serum?
a. Reduction of methyl green from green to colorless
b. Clot formation when acetic acid is added
c. Inhibition of red blood cell hemolysis
d. Lack of change in the color indicator
|6. Which of the following is considered to be a nonsuppurative complication of streptococcal infection?
a. Acute rheumatic fever
b. Scarlet fever
|7. All of the following are ways that bacteria can evade host defenses except
a. presence of a capsule.
b. stimulation of chemotaxis.
c. production of toxins.
d. lack of adhesion to phagocytic cells.
|8. Antibody testing for Rocky Mountain spotted fever may not be helpful for which reason?
a. It is not specific.
b. It is too complicated to perform.
c. It is difficult to obtain a blood specimen.
d. Antibody production takes at least a week before detection.
|9. Which of the following enzymes is used to detect the presence of H. pylori infections?
|10. Which of the following reasons make serological identification of a current infection with Helicobacter pylori difficult?
a. No antibodies appear in the blood.
b. Only IgM is produced.
c. Antibodies remain after initial treatment.
d. No ELISA tests have been developed.
|11. M. pneumoniae infections are associated with which antibodies?
a. Cold agglutinins
b. Antibodies to ATPase
c. Antibodies to DNase
d. Antibodies to Proteus bacteria
|12. Which of the following best describes the principle of the IFA test for detection of antibodies produced in Rocky Mountain spotted fever?
a. Proteus antigens are used to determine crossreactivity.
b. A light microscope is used to detect antigen– antibody combination.
c. Whole bacteria are used to detect antibodies.
d. Antibodies are detected by direct fluorescence.