Microbiology Chapter 1 Test Bank

Correct Answer: A

Rationale: The Burri-Gins staining technique is used to identify capsule formation in bacteria. Capsules are protective layers around bacteria that can be visualized using this staining method. Capsules are important virulence factors for pathogens like Yersinia pestis, the causative agent of plague. This technique helps in differentiating encapsulated bacteria from non-encapsulated ones. Spore formation (B), acid resistance (C), and alkali resistance (D) are not properties that can be identified using the Burri-Gins technique, making them incorrect choices.

Correct Answer: C

Rationale: Step 1: Anthrax causative agent is Bacillus anthracis, which forms spores. Step 2: Spores are highly resistant structures that can survive for a long time. Step 3: These spores can germinate into active bacteria when conditions are favorable. Step 4: The presence of spores in the powder makes it dangerous even long after being mailed. Summary: A: Incorrect - Anthrax does not form a protein capsule. B: Incorrect - Anthrax does not form a polysaccharide capsule. C: Correct - Anthrax forms spores that are highly resistant. D: Incorrect - Anthrax does not form flagella.

Correct Answer: B

Rationale: The correct answer is B: CDC. The Centers for Disease Control and Prevention (CDC) is responsible for establishing hand-washing guidelines in healthcare settings to prevent infections. CDC is a leading authority in public health and provides evidence-based recommendations. OSHA (A) focuses on workplace safety, NIAD (C) is not a recognized organization, and WHO (D) provides global health guidelines but CDC is the primary authority for hand hygiene in the US healthcare system.

Correct Answer: C

Rationale: The correct answer is C: Measles serological test. This is because the clinical presentation of high fever, maculopapular rash, and Filatov-Koplik's spots on the buccal mucosa are classic symptoms of measles. The presence of Filatov-Koplik's spots is highly specific for measles. Performing a measles serological test will help confirm the diagnosis by detecting measles-specific antibodies in the blood. Incorrect choices: A: Mumps serological test - Mumps typically presents with parotitis (swelling of the parotid glands) and not with Filatov-Koplik's spots. B: Enteroviruses serological test - Enteroviruses do not typically cause Filatov-Koplik's spots or the classic triad of symptoms seen in measles. D: Influenza virus serological test - Influenza virus does not cause Filatov-Koplik's spots and the characteristic rash seen

Correct Answer: A

Rationale: The correct answer is A: Balantidiasis. The large ciliated protozoa with a kidney-shaped macronucleus described in the stool sample is consistent with Balantidium coli, the causative agent of balantidiasis. Balantidium coli is the only ciliated protozoan parasite that infects humans and presents with these specific characteristics. Giardiasis (B) is caused by Giardia intestinalis, which is flagellated, not ciliated. Amoebiasis (C) is caused by Entamoeba histolytica, which has an amoeboid shape, not ciliated. Trichomoniasis (D) is caused by Trichomonas vaginalis, which is a flagellated protozoan and does not have a kidney-shaped macronucleus. Hence, the correct diagnosis in this case is Balantidiasis.