Effective for common gram-negative anaerobes: (A) Aztreonam, (B) Doxycycline, (C) Vancomycin, (D) Tobramycin
Answer is A. Aztreonam is effective for Gram-negative anaerobes like Bacteroides, Porphyromonas, Prevotella. Reference: Textbook of Microbiology; Anathanarayan and paniker&;s; 9th edition; Page no: 269