Infections of Legionella pneumophila are treated with:

Correct Answer: C

Rationale: The correct answer is C: Macrolides or fluoroquinolones. Legionella pneumophila is a bacterium that causes Legionnaires' disease, a severe form of pneumonia. Macrolides (like azithromycin) and fluoroquinolones (like levofloxacin) are the recommended first-line treatments due to their ability to penetrate into lung tissues where Legionella infects. Penicillins and cephalosporins (choice A) are not effective against Legionella as it is intracellular and resistant to these antibiotics. Ethambutol and isoniazid (choice B) are used to treat tuberculosis, not Legionella infections. Second and third generation cephalosporins (choice D) are also not effective against Legionella. Therefore, the best choice for treating Legionella pneumophila infections is macrolides or fluoroquinolones.

Correct Answer: D

Rationale: The correct answer is D, Kitt-Tarozzi medium. This medium is specifically designed for the isolation and cultivation of Clostridium tetani, the bacteria responsible for tetanus. The other options, Sabouraud agar, Endo agar, and Hiss medium, are not suitable for the growth of Clostridium tetani. Sabouraud agar is used for fungal cultures, Endo agar is a selective medium for enteric bacteria, and Hiss medium is used for the cultivation of anaerobic bacteria other than Clostridium tetani. Therefore, the Kitt-Tarozzi medium is the most appropriate choice for isolating and identifying the tetanus agent in this scenario.

Correct Answer: B

Rationale: The correct answer is B: Treponema pallidum. 1. Treponema pallidum is a spirochete bacterium known to cause syphilis. 2. Borrelia burgdorferi causes Lyme disease, not syphilis. 3. Leptospira interrogans causes leptospirosis, not syphilis. 4. Rickettsia rickettsii causes Rocky Mountain spotted fever, not syphilis. Therefore, Treponema pallidum is the causative agent of syphilis, making it the correct answer.

Correct Answer: B

Rationale: The correct answer is B because the term "infectious process" refers to all biological processes that occur after the attachment and penetration of microbes into the host organism, regardless of whether there are clinical manifestations. This includes the colonization, multiplication, and spread of the microorganisms within the host. Explanation: A: Incorrect because it only mentions the attachment and penetration of microbes into the microorganism, missing the subsequent processes. C: Incorrect because it is too specific, stating that the penetration of microbes always manifests clinically, which is not always the case. D: Incorrect because there is a correct answer, which is B, as explained above.

Correct Answer: B

Rationale: The correct answer is B because the nucleocapsid of viruses is composed of the genome (genetic material) and the capsid (protein coat). The genome contains the viral genetic information, while the capsid protects the genome and helps in viral attachment and entry into host cells. Choice A is incorrect because the envelope is not part of the nucleocapsid but surrounds the capsid in some viruses. Choice C is incorrect as spikes are surface proteins on the viral envelope, not part of the nucleocapsid. Choice D is also incorrect because the envelope is external to the capsid and genome in many viruses.

Correct Answer: A

Rationale: Step 1: Gram-negative bacillus indicates P. aeruginosa, known for causing wound infections. Step 2: Semi-transparent mucous colonies of blue-green color with a pearlescent appearance are characteristic of P. aeruginosa. Step 3: Specific odor of violets or jasmine is a unique feature of P. aeruginosa. Therefore, the correct answer is A: P. aeruginosa. Summary: - B: P. vulgaris typically forms yellow colonies and doesn't have the characteristic odor. - C: S. aureus forms creamy white colonies, not blue-green, and has a distinct odor. - D: S. pyogenes forms grayish-white colonies and doesn't have the unique characteristics described.

Correct Answer: A

Rationale: The correct answer is A: Giardia lamblia. This protozoan matches the description of the causative agent because it has two nuclei, four flagella, and a ventral adhesive disc. Giardia lamblia is commonly found in the duodenum and causes giardiasis. The other choices can be eliminated because Leishmania donovani causes visceral leishmaniasis, not the described symptoms. Entamoeba coli is a non-pathogenic amoeba found in the large intestine. Trypanosoma gambiense causes African trypanosomiasis and is transmitted by the tsetse fly, not matching the described characteristics.

Correct Answer: A

Rationale: The correct answer is A: HSV-1. Herpes simplex infections on lips and in the mouth are most commonly caused by HSV-1 due to its preference for infecting oral mucosa. HSV-2 typically causes genital herpes. HSV-6 and HSV-7 are less common and not typically associated with oral infections. Therefore, based on the typical presentation and epidemiology of herpes simplex infections, HSV-1 is the most likely cause in this scenario.

Correct Answer: B

Rationale: The correct answer is B: Biological oxidation. Haematrophic bacteria obtain energy through biological oxidation, where they break down organic compounds to generate ATP for cellular processes. This process involves the transfer of electrons from the substrate to an electron transport chain to produce energy. Heat production (A) is a byproduct of metabolism, not the primary way to obtain energy. In biosynthetic reactions (C), energy is utilized rather than generated. Cultivation in culture media (D) is a method of growing bacteria but does not directly provide energy. Therefore, the correct answer is B as it aligns with the metabolic process of haematrophic bacteria.