Which two of the following antibiotics are used to treat brucellosis? Multiple choice question.
rifampin
doxycycline
amphotericin
streptomycin
The correct answer and explanation is:
The correct two antibiotics used to treat brucellosis are:
Rifampin and Doxycycline
Explanation:
Brucellosis is a bacterial infection caused by the Brucella species. It is a zoonotic disease, commonly transmitted to humans through contact with infected animals or consumption of unpasteurized dairy products. Treating brucellosis effectively requires a combination of antibiotics that can penetrate cells because Brucella bacteria are intracellular pathogens—they survive and multiply inside host cells.
Why Rifampin and Doxycycline?
- Doxycycline: This is a tetracycline antibiotic that is effective against Brucella due to its ability to penetrate tissues and cells, targeting the bacteria inside host cells.
- Rifampin: This antibiotic works by inhibiting bacterial RNA synthesis. It has good intracellular penetration, making it effective against Brucella. Rifampin is often combined with doxycycline to reduce relapse rates and improve treatment efficacy.
The World Health Organization and most clinical guidelines recommend a combination therapy of doxycycline and rifampin for 6 weeks as the standard treatment for brucellosis. This combination improves bacterial clearance and reduces the chance of chronic infection or relapse.
Why Not the Others?
- Streptomycin is sometimes used in brucellosis treatment but typically as an alternative or in more severe cases. It is an aminoglycoside given by injection and has some activity against Brucella, but its use is less common than doxycycline and rifampin in standard therapy. It is often combined with doxycycline as well but is not as practical for routine treatment due to administration route and toxicity.
- Amphotericin is an antifungal agent, not an antibiotic. It is used to treat fungal infections and has no role in treating bacterial infections like brucellosis.
Summary:
The treatment of brucellosis requires antibiotics that can reach intracellular bacteria and be used in combination to prevent relapse. The standard and most widely accepted therapy involves:
- Doxycycline
- Rifampin
Both drugs work synergistically to eradicate Brucella and prevent chronic infection.