microbiology chapter 11 test bank

Correct Answer: B

Rationale: The correct answer is B: Bergey's Manual of Systematic Bacteriology. This manual is a comprehensive and authoritative resource specifically dedicated to bacterial taxonomy, classification, and identification. It provides detailed descriptions and classification schemes for bacteria, aiding in accurate identification and understanding of bacterial species. Gray's Anatomy (choice A) focuses on human anatomy, the WHO Manual (choice C) focuses on global health guidelines, and Darwin's Origin of Species (choice D) discusses evolution and natural selection, none of which are specialized taxonomic resources for bacteria.

Correct Answer: A

Rationale: The correct answer is A: Blood serum. In suspected cases of brucellosis, blood serum is typically analyzed in a common microbiological laboratory. This is because the bacteria causing brucellosis, Brucella species, can be detected through serological tests in the blood serum. The presence of specific antibodies against Brucella in the serum confirms the diagnosis. Spinal fluid (choice B) would be analyzed in cases of suspected central nervous system infections, which are not typical for brucellosis. Vomit mass (choice C) is not a common sample for microbiological analysis in cases of brucellosis. Urine (choice D) is not the preferred sample for detecting Brucella antibodies; blood serum is the primary choice for serological testing.

Correct Answer: C

Rationale: Step-by-step rationale: 1. Shigella is a nonmotile bacterium. 2. This lack of motility is a key characteristic used to differentiate it from other enteric bacteria. 3. Nonmotile nature of Shigella helps it to cause infections by invading the intestinal epithelial cells. 4. Therefore, choice C is correct as Shigella is indeed nonmotile. Summary: A: Incorrect - Shigella does not produce hydrogen sulfide. B: Incorrect - Shigella does not ferment lactose. D: Incorrect - Shigella is not mannitol positive.

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

Correct Answer: A

Rationale: Step-by-step rationale for why A is correct: 1. Clostridium tetani is known to produce tetanus toxin. 2. The tetanus toxin causes muscle rigidity and spasms characteristic of tetanus. 3. Clostridium perfringens is associated with gas gangrene, not tetanus. 4. Neisseria gonorrhoeae causes gonorrhea, not tetanus. 5. Bacillus anthracis causes anthrax, not tetanus. In summary, Clostridium tetani is the correct answer as it is specifically associated with causing tetanus, while the other choices are associated with different diseases.