A patient suffering form tuberculosis was treated with rifampicin, which caused drug resistance of tuberculosis mycobacteria. In order to reduce mycobacteria resistance, rifampicin should be combined with the following drug:

Correct Answer: A

Rationale: The correct answer is A: Isoniazid. When rifampicin is used alone, there is a risk of developing resistance. Isoniazid is commonly used in combination with rifampicin to prevent resistance by targeting different mechanisms in the bacteria. Isoniazid works by inhibiting mycolic acid synthesis, while rifampicin targets RNA polymerase. This combination therapy is known as the first-line treatment for tuberculosis. Choices B, C, and D are incorrect because they do not have the same mechanism of action as isoniazid and would not be effective in preventing rifampicin resistance.

Correct Answer: B

Rationale: The correct answer is B: Neisseria gonorrhoeae. This bacterium is responsible for causing gonorrhea. Neisseria gonorrhoeae is a sexually transmitted bacterium that infects the mucous membranes of the reproductive tract. It is known for causing symptoms such as painful urination and discharge. Chlamydia trachomatis (choice A) is another sexually transmitted bacterium but is not responsible for gonorrhea. Treponema pallidum (choice C) causes syphilis, not gonorrhea. Escherichia coli (choice D) is a common bacterium found in the gut and is not associated with causing gonorrhea. Therefore, Neisseria gonorrhoeae is the correct answer for this question.

Correct Answer: A

Rationale: The correct answer is A because protozoan emerging and reemerging diseases fall under Group I according to the classification of infectious diseases by the Centers for Disease Control and Prevention (CDC). Group I includes diseases caused by newly identified or known infectious agents that have increased in incidence or geographic range. Choice B (Group II) includes diseases that have re-emerged due to antimicrobial resistance or lack of previous vaccination. Choice C (Group III) encompasses diseases that can be transmitted from animals to humans, and choice D (Group IV) includes diseases that are caused by re-introduction of eradicated pathogens.

Correct Answer: A

Rationale: The correct answer is A: Bordetella pertussis. This bacterium is known for causing whooping cough due to its ability to produce toxins that damage the respiratory tract, leading to severe coughing fits. Clostridium tetani causes tetanus, Haemophilus influenzae can cause respiratory infections but not whooping cough, and Staphylococcus aureus is more commonly associated with skin infections. Therefore, A is the correct choice based on its specific association with the disease in question.

Correct Answer: A

Rationale: The correct answer is A: Metronidazole. Metronidazole is a synthetic antiprotozoan drug with high activity against Helicobacter pylori, a bacterium that can cause wound infections. Metronidazole specifically targets anaerobic bacteria like H. pylori, making it effective in preventing wound infections. Incorrect choices: B: Doxycycline hydrochloride - Doxycycline is primarily used for bacterial infections, not protozoan infections like H. pylori. C: Chingamin - Chingamin is not a commonly used drug for treating H. pylori infections or preventing wound infections. D: Acyclovir - Acyclovir is an antiviral drug used to treat herpes infections, not bacterial or protozoan infections like H. pylori.

Correct Answer: A

Rationale: The correct answer is A: Entamoeba histolytica. This protozoon is responsible for causing amoebic dysentery, which presents with bloody diarrhea. The "raspberry jelly" appearance of stool is due to the presence of mucosal lining and blood. The large mononuclear cells with absorbed red blood cells are characteristic of the histopathology of Entamoeba histolytica infection. Giardia lamblia (B) causes watery diarrhea, not bloody stools. Campylobacter jejuni (C) is a bacterial pathogen associated with gastroenteritis, but does not typically cause bloody diarrhea. Toxoplasma gondii (D) causes toxoplasmosis, a systemic infection with symptoms such as fever and lymphadenopathy, but not bloody diarrhea.

Correct Answer: A

Rationale: The correct answer is A because fires from combustibles such as wood fall under Class A fires. Type A fire extinguishers are specifically designed to extinguish fires involving ordinary combustible materials like wood, paper, and cloth. Choice B, C, and D are incorrect because they do not correspond to the correct classification of the fire. Choice B refers to Class B fires involving flammable liquids, Choice C refers to Class C fires involving electrical equipment, and Choice D refers to Class D fires involving combustible metals. It is crucial to match the type of fire extinguisher with the type of fire to effectively combat the fire.

Correct Answer: D

Rationale: The correct answer is D because nosocomial infections can be transmitted through various routes, including air droplets, fecal-oral mechanism, contact mechanism, and parenteral mechanism. Air droplets can carry infectious agents through the air, while contact with contaminated surfaces or individuals can spread infections. Fecal-oral transmission occurs through ingesting contaminated food or water. Parenteral transmission involves the introduction of pathogens directly into the bloodstream. Therefore, all the options listed in D are correct routes for transmission of nosocomial infections. Choices A, B, and C are incorrect because they do not encompass all possible routes of transmission for nosocomial infections.

Correct Answer: A

Rationale: The correct answer is A: viral DNA polymerase. This enzyme is essential for replicating the viral DNA during the herpesvirus life cycle. It catalyzes the synthesis of new DNA strands using the viral genomic template. Ribonucleotide reductase (B) is involved in nucleotide synthesis, but not directly in DNA replication. Neuraminidase (C) is an enzyme found in influenza viruses, not herpesviruses. Thymidine kinase (D) is an enzyme that phosphorylates thymidine, but its role is more related to nucleotide metabolism rather than viral DNA replication.