system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
A patient presents with fever, cough with sputum and weight loss. He has a history of not completing treatment for tuberculosis thrice in the past. XDR-TB is suspected. How is XDR-Tb defined?
assistant
The correct answer is  XDR-TB (Extensively drug-resistant TB) is defined as MDR TB (Resistant to rifampicin and isoniazid) + Resistant to one fluoroquinolone (eg. ofloxacin) + resistance to one injectable second line drug (Amikacin or kanamycin or capreomycin). Reference: Ananthanarayan and Paniker&;s Textbook of Microbiology Tenth edition