P. aeruginosa is frequently isolated from nonsterile sites (mouth swabs, sputum, etc.), and, under these circumstances, it often represents colonization and not infection. The isolation of P. aeruginosa from nonsterile specimens should, therefore, be interpreted cautiously, and the advice of a microbiologist or infectious diseases physician/pharmacist should be sought prior to starting treatment. Often no treatment is needed.
When P. aeruginosa is isolated from a sterile site (blood, bone, deep collections), it should be taken seriously, and almost always requires treatment.[citation needed]
P. aeruginosa is naturally resistant to a large range of antibiotics and may demonstrate additional resistance after unsuccessful treatment, in particular, through modification of a porin. It should usually be possible to guide treatment according to laboratory sensitivities, rather than choosing an antibiotic empirically. If antibiotics are started empirically, then every effort should be made to obtain cultures, and the choice of antibiotic used should be reviewed when the culture results are available.
Phage therapy against ear infections caused by Pseudomonas aeruginosa was reported in the journal Clinical Otolaryngology in August 2009[30]
Antibiotics that have activity against P. aeruginosa include:
aminoglycosides (gentamicin, amikacin, tobramycin)
quinolones (ciprofloxacin, levofloxacin, and moxifloxacin)
cephalosporins (ceftazidime, cefepime, cefoperazone, cefpirome, but not cefuroxime, ceftriaxone, cefotaxime)
antipseudomonal penicillins: ureidopenicillins and carboxypenicillins (piperacillin, ticarcillin: P. aeruginosa is intrinsically resistant to all other penicillins)
carbapenems (meropenem, imipenem, doripenem, but not ertapenem)
polymyxins (polymyxin B and colistin)[31]
monobactams (aztreonam)
