Indications for Fluoroquinolones Fluoroquinolones are active against the following: Haemophilus influenzae Moraxella catarrhalis Mycoplasma species Chlamydia species Chlamydophila species Legionella species Enterobacterales (formerly Enterobacteriaceae) Pseudomonas aeruginosa (particularly ciprofloxacin) Mycobacterium tuberculosis Some atypical mycobacteria Some methicillin-sensitive staphylococci Nosocomial methicillin-resistant staphylococci (MRSA) are usually resistant.