Saturday November 8, 2008
Do anti-Pseudomonal agents increase the Pseudomonas aeruginosa colonization?

Jose Martinez published a paper in Intensive Care Medicine to clarify the issues.

Setting: Prospective study in two medical ICU.

Measurements: Surveillance cultures from nares, pharynx, rectum and respiratory secretions. Acquisition of resistance was defined as the isolation, after 48 hrs of ICU stay, of an isolate resistant to a given antibiotics.

Results: Forty-four (13%) patients acquired 52 strains of P. aeruginosa.

Administration of piperacillin-tazobactam for more than/= 3 days and use of amikacin for more than/= 3 days were positively associated with acquisition of P. aeruginosa, whereas use of quinolones and antipseudomonal cephalosporins was protective.

Exposure to quinolones and cephalosporins was not associated with the acquisition of resistance, whereas it was linked with usage of all other agents. Neither quinolones nor cephalosporins were a major determinant on the emergence of resistance to themselves, as resistance to these antibiotics developed at a similar frequency in non-exposed patients.

Conclusions: In critically ill patients, quinolones and antipseudomonal cephalosporins may prevent the acquisition of P. aeruginosa and may have a negligible influence on the acquisition and emergence of resistance.



Reference:

Martinez J, Delgado E, Marti S, Marco F et al. Influence of antipseudomonal agents on Pseudomonas aeruginosa colonization and acquisition of resistance in critically ill medical patients.
Intensive Care Medicine 2008 Published online October 21st 2008.