The choice of a specific antimicrobial agent depends on anti-biotics susceptibility patterns of isolated strains. P. mirabilis is susceptible to nearly all antimicrobials except tetracycline. P. mirabilis is sensitive to ampicillin; broad-spectrum peni-cillins, such as ticarcillin, piperacillin; first-, second-, and third-generation cephalosporins; imipenem; and aztreonam. Resistance to these antibiotics is not a significant problem; only 10–20% of strains develop resistance to ampicillin and first-generation cephalosporins. Development of resistance to extended-spectrum beta-lactams is uncommon.
P. vulgaris and P. penneri are sensitive to trimethoprim andsulfamethoxazole, quinolones, imipenem, aminoglycosides, and fourth-generation cephalosporins. They are resistant to ampicillin and first-generation cephalosporins. The resis-tance is mediated by activation of an inducible chromosomal beta-lactamase occurring in up to 30% of these strains.
Hand washing holds the key to prevent transmission from patient to patient via medical personnel. A vaccine derived from purified mannose-resistant/Proteus-like (MR/P) fimbriae proteins has been evaluated to prevent infection in experimen-tal mouse models and is still under clinical research. The vac-cine is yet to be evaluated in humans.