This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Systemic Bacteriology (Gram Positive Bacilli, Gram Negative Bacilli), Subject name: Microbiology
Multidrug-resistant S. typhi ) are resistant to all except- 
Select and explain. 
A. Chloramphenicol, B. Ampicillin, C. Ciprofloxacin, D. Septran
C: Ciprofloxacin
Answer: C: Ciprofloxacin 
Explanation: Isolates of S. typhi resistant to chloramphenicol, ampicillin, and co-trimoxazole designated as multidrug-resistant S. typhi . Ciprofloxacin became drug of choice for typhoid fever in patients of all age groups, infected or likely to be infected with fully drug susceptible S. typhi or MDR-ST. Alternative : Third-generation cephalosporins (cefixime for 7 to 14 days or ceftriaxone for 10 to 14 days) and azithromycin (for 7 days).