Resistance patterns in Pseudomona aeruginosa

Abstract number: r1970

Orellana  M.A., Aramendi  M., Galera  G., Sanchez  M.T., Fernandez  T., Aparicio  V., Amérigo  M.A.

Objective: 

To study the sensibility and the resistance patterns of P. aeruginosa isolated in different clinic samples in outpatients.

Methods: 

180 P. aeruginosa strains were studied between January 2004 and September 2005. The identification and sensibility were performed by the MicroScan Walkaway System (DADE-Behring) according to NCCLS criteria. The antibiotics studied were: Amikacin (Ak), Aztreonam (AZT), Cefepime (Cpe), Cefotaxime (Cft),Ceftazidime (Caz), Ciprofloxacin (Cp), Gentamicin (Gm), Imipenem (Im), Meropenem (Me), Ofloxacin (Ofl), Piperacillin/Tazobactam (P/T), Piperacillin (Pi), Ticarcillin (Ti) and Tobramicin (To).

Results: 

P. aeruginosa were isolated in: urine 37 (20.56%), wounds 61 (33.89%), otics exudates (ex.) 45 (25.0%), sputum 10 (5.56%), conjunctival ex. 8 (4.44%), nasopharingeal ex. 6 (3.33%), vaginal ex. 3 (1.67%), urhetral ex.2 (1.11%), nasal ex. 1 (0.56%) and other 7 (3.89%).

-The sensibility to antibiotics studied were: Ak 93.9%, Azt 86.1%, Cpe 95.6%, Cft 19.4%, Caz 97.8%, Cp 87.8%, Gm 85.6%, Im 93.9%, Me 99.5%, Ofl 74.6%, P/T 99.6%, Pi 97.8%, Ti 95.0% and To 95.6%.

-The resistance patterns more frequent were: Sensitive to all antibiotics studied 17 (9.44%); resistance to Cft: 95 (52.78%); resistance to Cp + Ofl + Cft: 12 (6.67%); Cft + Gm: 4 (2.22%); Cp + Ofl + Cft + Azt: 7 (3.89%); Cp + Ofl: 4 (2.22%); Cft + Azt: 6 (3.33%); Cft + Im: 3 (1.67%); Gm: 3 (1.67%); Cp + Ofl + Im: 3 (1.67%); Gm + To + Ak + Cp + Ofl + Cft + Caz + Cpe + Azt: 3(1.67%) and other 23 (12.78%).

Conclusions: 

Wounds were the samples where P. aeruginosa was isolated most frequent.

-The antibiotics studied have a good activity against P. aeruginosa, excep Cefotaxime (only 19.4%).

-There is a low percentage of P. aeruginosa sensitive to all antibiotics studied.

-The resistance patterns most frequent were: resistance to Cefotaxime and Cefotaxime with quinolones (Cp + Ofl).