ATI RN
microbiology chapter 10 test bank Questions
Question 1 of 5
The protozoan that lacks a cyst stage and therefore must be transferred quickly from host to host is:
Correct Answer: B
Rationale: The correct answer is B: Protozoans. Protozoans lack a cyst stage, which is a protective, dormant stage that allows them to survive in harsh conditions outside the host. Without a cyst stage, protozoans must be transferred quickly between hosts to avoid exposure to unfavorable environments. Molds (A) are fungi that reproduce through spores and do not have a cyst stage like protozoans. Helminths (C) are parasitic worms that have complex life cycles involving different hosts but do not rely on a cyst stage for survival. Viruses (D) are not considered protozoans and do not have a cyst stage, but they are not classified as protozoans.
Question 2 of 5
A tube with bacterial culture is very cloudy on the surface but clear in the rest. This shows that:
Correct Answer: A
Rationale: The correct answer is A because the cloudy surface indicates that the bacteria are growing where oxygen is present (aerobes), causing turbidity. The clear bottom suggests that the bacteria are not growing in the absence of oxygen. Choices B, C, and D are incorrect because the observed phenomena do not necessarily indicate the need for an anaerobic chamber, enzyme deficiencies, or the microorganism being non-aerotolerant.
Question 3 of 5
A 30 y.o. patient is diagnosed with amebic dysentery. This diagnosis was bacteriologically confirmed. Name the preparation for its treatment:
Correct Answer: A
Rationale: The correct answer is A: Metronidazole. Amebic dysentery is caused by the parasite Entamoeba histolytica, not bacteria. Metronidazole is the drug of choice for treating this parasitic infection. It works by disrupting the DNA structure of the parasite, leading to its death. Mebendazole (B) is used to treat certain worm infections, not amebic dysentery. Itrakonazole (C) is an antifungal medication and not effective against parasites. Furacillin (D) is an antibacterial agent and not suitable for treating parasitic infections like amebic dysentery.
Question 4 of 5
Which bacteria are resistant to antibiotics and commonly found in hospitals?
Correct Answer: A
Rationale: The correct answer is A, Staphylococcus aureus (MRSA), because it is known to be resistant to many antibiotics commonly used in hospitals. MRSA poses a significant threat in healthcare settings due to its resistance, making it difficult to treat. Choice B, Escherichia coli, is not typically resistant to antibiotics. Choice C, Salmonella enterica, and Choice D, Vibrio cholerae, are not commonly associated with antibiotic resistance in hospitals. Therefore, A is the correct answer based on its well-documented antibiotic resistance in healthcare settings.
Question 5 of 5
What drug should be administered?
Correct Answer: A
Rationale: The correct answer is A: Doxycycline. It is a broad-spectrum antibiotic effective against a wide range of bacteria, including those causing infections like Lyme disease and pneumonia. Doxycycline is often the first-line treatment for these infections due to its efficacy and low risk of resistance. Chloramphenicol (B) has serious side effects and is reserved for specific cases. Penicillin (C) is not effective against all bacteria and may not cover the specific infection. Streptomycin (D) is mainly used for certain types of bacterial infections and is not the optimal choice for the conditions mentioned in the question.