<s>[INST] context: Ciprofloxacin (prototype) It is the most potent first generation FQ acti\*e against a broad range of bacteria, the most susceptible ones are the aerobic gram-negati\*e bacilli, especially the Enterobacteriaceae and Neisseria. The MIC of ciprofloxacin against these bacteria is usually < 0.1 J.Ig/ml, while grampositive bacteria are inhibited at relatively higher concentrations. The spectrum of action E summarized below: Highly susceptible E. coli K. pneumoniae Enterobacter Salmonella typhi other Salmonella Shigella Proteus Neisseria gonorrhoeae N. meningitidis H. influenzae H. ducreyi Campylobacter jejuni Yersinia enterocolitica Vibrio cholerae Moderately susceptible Pseudomonas aeruginosa Staph. aureus (including few MRSA) Staph. epidermidis Branhamella catarrhalis Legionella Brucella Listeria Bacillus anthracis Mycobact. tuberculosis Organisms which have shown low /variable susceptibility are: Strep. pyogenes, Strep. faecalis, Strep. pneumoniae, Mycoplasma, Chlamydia, Mycobact. kansasii, Mycobact. avium. ESSENTIALS OF MEDICAL PHARMACOLOGY K.D.TRIPATHI SIXTH EDITION PAGE NO:687,688 [/INST] question: Which of the following is an antipseudomonal antibiotic? | options: A: Ciprofloxacin B: Vancomycin C: Cefaclor D: Tetracycline | answer: A </s>