microbiology a systems approach test bank

Correct Answer: A

Rationale: Step-by-step rationale: 1. Mycobacterium leprae is the correct answer because it is the bacterium responsible for causing leprosy. 2. Neisseria gonorrhoeae causes gonorrhea, not leprosy. 3. Escherichia coli is associated with gastrointestinal infections, not leprosy. 4. Staphylococcus aureus causes various skin infections, but not leprosy. In summary, Mycobacterium leprae is the correct choice because it is the specific bacterium known to cause leprosy, while the other options are associated with different diseases.

Correct Answer: D

Rationale: The correct answer is D: reemerging diseases. Group II category diseases by the NIAID are those that have reemerged or have the potential to reemerge. This classification helps prioritize research and resources. Choice A is incorrect because new foodborne pathogens fall under different categories. Choice B is incorrect as eradicated diseases are not part of the reemerging group. Choice C is incorrect because bioterrorism agents are classified separately. Therefore, the correct answer is D as it aligns with the purpose of Group II category diseases.

Correct Answer: A

Rationale: The correct answer is A: Entamoeba histolytica. This protozoan parasite causes amoebic dysentery and is characterized by cysts with four nuclei in fecal smears. It is commonly associated with chronic diarrhea. Balantidium coli (B) presents with large ciliated trophozoites, not cysts. Giardia lamblia (C) has trophozoites with flagella and causes giardiasis, not cysts with four nuclei. Trichomonas hominis (D) typically has a pear-shaped trophozoite and is not associated with cysts with four nuclei.

Correct Answer: B

Rationale: The correct answer is B: Escherichia coli. E. coli is the most common cause of UTIs due to its ability to colonize the urinary tract. It possesses adhesive factors that enable it to attach to the bladder and cause infection. Clostridium tetani causes tetanus, Mycobacterium leprae causes leprosy, and Bacillus anthracis causes anthrax, none of which are typically associated with UTIs. E. coli's prevalence in the gut and its pathogenic mechanisms make it the leading cause of UTIs.

Correct Answer: C

Rationale: Rationale: 1. The presence of ulcers in animals suggests a parasitic infection. 2. Mosquitoes as carriers indicate a protozoan transmitted through insect bites. 3. Among the choices, Plasmodium falciparum causes malaria transmitted by mosquitoes. 4. Leishmania tropica major causes cutaneous leishmaniasis, not ulcers. 5. Balantidium coli causes intestinal infections, not skin ulcers. 6. Trypanosoma cruzi causes Chagas disease, not skin ulcers.