Microbiology Chapter 11 Test Bank

Correct Answer: A

Rationale: The correct answer is A: IgG. Anti-tetanus gamma globulin is produced by hyperimmunization, leading to a high concentration of specific antibodies, predominantly IgG. IgG is the most abundant immunoglobulin in the blood and provides long-term immunity against tetanus. IgA is mainly found in mucosal areas, not in gamma globulin preparations. IgM is the first antibody produced in response to an infection and is not the prevailing class in this preparation. IgE is associated with allergic reactions and parasitic infections, not with anti-tetanus immunity.

Correct Answer: B

Rationale: The correct answer is B: Absence of hemagglutination. In the reaction inhibition of hemagglutination, specific antibodies bind to antigens on red blood cells, preventing their agglutination. This results in the absence of visible clumping of red blood cells, which is known as hemagglutination. Therefore, the presence of specific antibodies is visualized by the absence of hemagglutination. Incorrect Choices: A: Absence of hemolysis - Hemolysis refers to the rupture of red blood cells, which is not relevant in the context of hemagglutination. C: Presence of hemagglutination - This is the opposite of what is expected when specific antibodies are present and inhibiting hemagglutination. D: Presence of hemolysis - Again, hemolysis is not directly related to the inhibition of hemagglutination by specific antibodies.

Correct Answer: A

Rationale: The correct answer is A: Clostridium perfringens. This bacterium fits all the characteristics mentioned: Gram-positive rods with spore formation, motile, and gas production in nutrient broth. Clostridium perfringens is known to cause gas gangrene, which aligns with the gas production in nutrient broth. Bacillus anthracis (B) causes anthrax and does not typically produce gas. Clostridium tetani (C) causes tetanus and does not form spores that are motile. Bacillus cereus (D) is a common cause of food poisoning and does not cause gas gangrene.

Correct Answer: D

Rationale: The correct answer is D: Cell cultures. Rotavirus diagnosis involves detecting viral antigens in stool samples using cell cultures. Cell cultures allow for the replication of the virus, facilitating its identification. A: Egg inoculation and B: Sensitive laboratory animals are not commonly used for Rotavirus diagnosis due to ethical concerns and practical limitations. C: Ascoli test is used for detecting specific proteins in serum, not for Rotavirus detection in stool samples. In summary, cell cultures are the most appropriate method for laboratory diagnosis of Rotavirus infection due to their ability to support viral replication and antigen detection.

Correct Answer: A

Rationale: Rationale: 1. Spore-forming, Gram-positive rods: Characteristics shared by Clostridium and Bacillus. 2. Motile and gas production in nutrient broth: Clostridium perfringens is motile and produces gas, distinguishing it from Bacillus species. 3. Clostridium perfringens causes gas gangrene, correlating with gas production. 4. Bacillus anthracis causes anthrax, not related to wound infections. 5. Clostridium tetani causes tetanus, not associated with gas production. 6. Bacillus cereus causes food poisoning, not commonly associated with wound infections. Summary: - A is correct (Clostridium perfringens) due to motility, gas production, and wound infection correlation. - B (Bacillus anthracis) causes anthrax, not wound infections. - C (Clostridium tetani) causes tetanus, not gas production. - D (B