microbiology an introduction tortora test bank

Correct Answer: A

Rationale: The correct answer is A: Neisser's staining. Neisser's staining is used to detect metachromatic granules in bacteria, which appear as dark blue-staining granules at the ends of rod-shaped bacteria in diphtheria. This technique specifically targets these granules, making it ideal for identifying Corynebacterium diphtheriae, the causative agent of diphtheria. Ziehl-Neelsen staining is used for acid-fast bacteria like Mycobacterium tuberculosis, Gram staining is for classifying bacteria based on cell wall composition, and Giemsa staining is used for detecting parasites and certain blood cells, making them incorrect for identifying granules in diphtheria.

Correct Answer: C

Rationale: The correct answer is C because there is no obligatory vaccine for Neisseria meningitidis in Bulgaria. The rationale for this is that while vaccines are available for meningococcal disease, they are not mandatory in Bulgaria. Therefore, this statement is incorrect. A: This statement is correct as Waterhouse-Friderichsen syndrome can occur during meningococcemia due to rapid progression of the infection leading to adrenal gland failure. B: This statement is incorrect as Neisseria meningitidis is most common in infants, children, and adolescents, with a second peak in young adults. D: This statement is correct as Neisseria meningitidis is transmitted through respiratory secretions, such as coughing or kissing, especially in close contacts like household members or roommates.

Correct Answer: A

Rationale: The correct answer is A because Fluconazole, Orungal, and Nizoral are antifungal medications commonly used for prevention of fungal infections. Fluconazole is a systemic antifungal agent, Orungal (Itraconazole) is used for various fungal infections, and Nizoral (Ketoconazole) is effective against a wide range of fungal infections. Choices B, C, and D do not contain antifungal medications and are unrelated to preventing fungal infections.

Correct Answer: A

Rationale: The correct answer is A: Clostridium perfringens. This is because Clostridium perfringens is a Gram-positive rod bacterium that forms terminal spores. It is commonly associated with deep tissue infections and can cause gas gangrene. Bacillus anthracis (B) causes anthrax and does not typically form spores at the terminal end. Clostridium tetani (C) causes tetanus and Bacillus cereus (D) is more commonly associated with food poisoning. In this case, the presence of terminal spores along with the clinical presentation of a deep tissue infection points towards Clostridium perfringens as the most likely causative agent.

Correct Answer: C

Rationale: Granulomatosis infantiseptica is commonly caused by Listeria monocytogenes, a bacterium known to infect newborns. It can lead to granulomatous lesions in various organs. Staphylococcus aureus and Mycobacterium tuberculosis are not typical causes of this condition in infants. Choice D is incorrect as it suggests all listed bacteria are responsible, which is not accurate. Therefore, the correct answer is C as Listeria monocytogenes is the specific pathogen associated with granulomatosis infantiseptica.