Indications for Aminoglycosides Aminoglycosides are used for Serious gram-negative bacillary infections (especially those due to Pseudomonas aeruginosa) Aminoglycosides are active against most gram-negative aerobic and facultative anaerobic bacilli but lack activity against anaerobes and most gram-positive bacteria, except for most staphylococci; however, some gram-negative bacilli and staphylococci are resistant.