Drug of choice for Brucella infection is

Correct Answer: A

Rationale: In the context of treating Brucella infection, the drug of choice is Tetracycline. This is because Brucella is an intracellular bacterium, and Tetracycline has the ability to penetrate cells effectively, making it an important component of the treatment regimen. Tetracycline works by inhibiting bacterial protein synthesis, thereby halting the growth and spread of the Brucella bacteria. Gentamycin (option B) is an aminoglycoside antibiotic that is more effective against aerobic bacteria and is not typically used as a first-line treatment for Brucella infections. Ampicillin (option C) is a beta-lactam antibiotic that is more commonly used for treating gram-positive and some gram-negative bacterial infections, but it is not the drug of choice for Brucella. Sulfonamides (option D) inhibit folic acid synthesis in bacteria, but they are not as effective against intracellular bacteria like Brucella compared to Tetracycline. In an educational context, understanding the rationale behind the choice of Tetracycline for Brucella infection highlights the importance of selecting appropriate antibiotics based on the mechanism of action, spectrum of activity, and ability to penetrate cells effectively. This knowledge is crucial for healthcare professionals in making informed decisions when treating bacterial infections to ensure optimal patient outcomes.

Correct Answer: A

Rationale: In this question, the correct answer is option A: I, II, and III are correct. The drugs Timentin (ticarcillin-clavulanate), Augmentin (amoxicillin-clavulanate), and Oxacillin are all active against penicillinase-producing Staphylococcus aureus. Timentin and Augmentin contain clavulanate, which is a beta-lactamase inhibitor that helps in overcoming the resistance caused by penicillinase production by the bacteria. This combination allows the antibiotics to remain effective against penicillinase-producing strains of Staphylococcus aureus. Oxacillin, on the other hand, is a penicillinase-resistant penicillin. It is not affected by the presence of penicillinase enzymes produced by bacteria, making it effective against penicillinase-producing Staphylococcus aureus. Option B (Only III is correct) is incorrect because Timentin and Augmentin, in addition to Oxacillin, are also active against penicillinase-producing Staphylococcus aureus. Option C (I and II are correct) is incorrect as it excludes Oxacillin, which is also effective against penicillinase-producing Staphylococcus aureus. Option D (II and III are correct) is incorrect as it excludes Timentin, which is another drug that is active against penicillinase-producing Staphylococcus aureus. Understanding the mechanisms of action of these antibiotics is crucial in the treatment of bacterial infections and in combating antibiotic resistance. By knowing which drugs are effective against specific pathogens, healthcare providers can make informed decisions when prescribing antibiotics, ultimately leading to better patient outcomes.

Correct Answer: B

Rationale: In the context of drugs and the immune system, the correct answer to the question is B) Salmonella infection. Chloramphenicol is an antibiotic that is effective against a broad spectrum of bacteria, including Salmonella species. It inhibits bacterial protein synthesis by binding to the bacterial ribosome. Staphylococcal infections are commonly treated with other antibiotics such as penicillinase-resistant penicillins or cephalosporins, making option A incorrect. Viral infections do not respond to antibiotics like chloramphenicol, so option C is incorrect. Amoebic dysentery is typically treated with anti-protozoal medications like metronidazole, making option D incorrect. In an educational context, understanding the appropriate use of antibiotics based on the specific pathogen is crucial to prevent antibiotic resistance and ensure effective treatment. This question highlights the importance of matching the right drug to the specific type of infection, emphasizing the need for accurate diagnosis and targeted therapy to combat infectious diseases effectively.

Correct Answer: D

Rationale: In the context of drugs and the immune system, understanding antiviral agents is crucial. The correct answer, option D, includes ganciclovir, foscarnet, and acyclovir as agents active against cytomegalovirus (CMV). Ganciclovir works by inhibiting viral DNA polymerase, foscarnet by blocking viral DNA polymerase and reverse transcriptase, and acyclovir by inhibiting viral DNA polymerase. These mechanisms target different stages of the viral replication cycle, making them effective against CMV. Option A is incorrect because only selecting ganciclovir would limit the treatment options for CMV. Option B is incorrect as acyclovir is not effective against CMV. Option C is incorrect because acyclovir is not active against CMV, despite foscarnet being effective. Understanding the specific mechanisms and spectrum of activity of antiviral agents is vital for selecting appropriate treatments for viral infections like CMV, especially in immunocompromised patients.

Correct Answer: C

Rationale: The correct answer is C) Carbenicillin. Carbenicillin is a semisynthetic penicillin that is destroyed by acid. This property is important because carbenicillin needs to be administered in a form that can resist stomach acid so that it can reach the intestines where it can be absorbed into the bloodstream. Option A) Phenoxymethyl penicillin is not destroyed by acid, so it is not the correct answer to this question. Option B) Ampicillin and Option D) Cloxacillin are both penicillins, but they are not semisynthetic penicillins that are destroyed by acid like carbenicillin. Therefore, they are incorrect choices in this scenario. Understanding the properties of different antibiotics, including how they are affected by factors like acidity in the stomach, is crucial for healthcare professionals when prescribing medications to ensure their efficacy. This knowledge helps in selecting the right antibiotic for a particular infection and understanding how to administer it for optimal results. It also highlights the importance of pharmaceutical companies designing medications that can withstand different conditions in the body for effective treatment.