Estudio retrospectivo de la resistencia de 1.943 aislados clínicos de Pseudomonas aeruginosa a amikacina, tobramicina, gentamicina, ceftazidima, cefepima, meropenem, piperacilina-tazobactam y ciprofloxacino durante un periodo de 5 años.La resistencia global osciló desde el 2,07% para amikacin al 15,89% para ciprofloxacino con diferencias según la procedencia del paciente, servicios y muestras: los aislamientos de pacientes ingresados fueron significativamente más resistentes que los de los ambulatorios, (p≤0,001: tobramicina, 13,74% vs 5,05%; gentamicina, 13,74% vs 8,26%; ceftazidima, 12,67% vs 4,24%; cefepima, 11,48% vs 7,07%; meropenem, 8,57% vs 2,06%), salvo para amikacina (1,98% vs 2,2%, p=0,74), piperacilina/tazobactam (6,07% vs 4,55%, p=0,14) y ciprofloxacino (17,17% vs 13,97%, p=0,06). Los servicios de críticos y las muestras respiratorias presentaron las tasas más altas de resistencia mientras que los servicios quirúrgicos y las muestras invasivas presentaron la mejor sensibilidad. Un 4,8% de los aislamientos fueron multirresistentes. Comparado con nuestro anterior estudio (1.992-2.003) observamos un descenso significativo de resistencia a amikacina (7,74% vs 2,07%, p<0,001), tobramicina (13,61% vs 10,26%, p<0,001), gentamicina (30,85% vs 14,73%, p<0,001) ceftazidima (14,63% vs 9,28%, p<0,001), cefepima (12,31% vs 9,71%, p=0,005) y meropenem (8,84% vs 5,96%, p=0,001) y se mantienen piperacilina/tazobactam (4,26% vs 5,46%, p=0,06) y ciprofloxacino (16,02% vs 15,89%, p=0,89). En nuestra zona se ha producido en los últimos años un cambio en los patrones de susceptibilidad de P. aeruginosa, alejado del descrito a nivel nacional, lo que incide en la importancia del seguimiento local periódico de la susceptibilidad de los aislados clínicos.

Retrospective study of antimicrobial susceptibility of 1.943 Pseudomonas aeruginosa clinical isolates to amikacin, tobramycin, gentamicin, ceftazidime, cefepime, meropenem, piperacillin-tazobactam and ciprofloxacin during a five year period. The percentage of resistance went from 2.07% to amikacin from 15.89% to ciprofloxacin. These percentages showed differences depending on the extra or intrahospitalary origin, departments and samples. Isolates from hospital patients were significantly more resistant than the ones from ambulatory patients (p≤0.001:tobramycin, 13.74% vs 5.05%; gentamicin, 13.74% vs 8.26%; ceftazidime, 12.67% vs 4.24%; cefepime, 11.48% vs 7.07%; meropenem, 8.57% vs 2.06%),except for amikacin (1.98% vs 2.2%, p=0.74), piperacillin/tazobactam (6.07% vs 4.55%, p=0.14) and ciprofloxacin (17.17% vs 13.97%, p=0.06). Critical care department and respiratory samples showed the highest resistance percentages while surgery department and invasive samples showed the lowest. Multidrug-resistance was found in 4.8% of the isolates. When comparing our data with those from our previous study (1992-2003), we observed a significant reduction in antibiotic resistance to amikacin (7.74% vs 2.07%, p<0.001), tobramycin (13.61% vs 10.26%, p<0.001), gentamicin (30,85% vs 14.73%, p<0,001), ceftazidime (14.63% vs 9,28%, p<0.001), cefepime (12,31% vs 9.71%, p=0.005), and meropenem (7.74% vs 2.07%, p=0.001); and there were no changes in resistance to piperacillin- tazobactam (4.26% vs 5.46%, p=0,06) and ciprofloxacin (16.02% vs 15.89%, p=0.89). In the last years, the susceptibility pattern of P. aeruginosa to antimicrobial agents has changed in our health district, and it is very different from the one described in national studies so it would be very important to monitore susceptibility of clinical isolates periodically.