Antimicrobial susceptibility among Pseudomonas aeruginosa isolates from a central hospital in the centre of Portugal: a6year surveillance

Abstract number: P1631

Pereira S., Albuquerque L., Oliveira H., Leitão R., Cardoso O.

Objectives:Pseudomonas aeruginosa (PA) is an important nosocomial pathogen causing a wide spectrum of infections and leading to substantial morbidity and mortality. In order to apply optimal therapeutic guidelines physicians must be aware of recent resistance surveillance, and epidemiological data. The main objective was to determine antimicrobial susceptibility of PA isolates in order to assist the guidelines for empirical regimens and infection control measures.

Methods: From April 2003 to April 2009, 2210 PA isolates were collected in Centro Hospitalar de Coimbra. Nosocomial isolates (N = 1411) and ambulatory ones (N = 799) were obtained from sputum (40.2%), urine (23.7%), exudates (13.8%), blood (5.1%) and other sources (12.2%). They were identified with API32GN (bioMérieux) and MicroScan WalkAway (Dadebehring) and susceptibility patterns were determined with these panels. Susceptibilities to Piperacillin (PIP), Piperacillin plus Tazobactam (TZP), Aztreonam (AZT), Ceftazidime (CAZ), Imipenem (IP), Meropenem (MP), Amikacin (AMK), Gentamicin (GN), and Ciprofloxacin (CIP) were guideline by CLSI.

Results: Overall, AMK was the best agent (87.1%), followed by TZP (86.5%), MP (83.6%), PIP (83.4%), CAZ (80.0%), AZT (76.4%), IP (75.3%), GN (70.4%) and CIP (63.1%). Nosocomial isolates responded to AMK (83.4%), TZP (81.1%), PIP (76.8%), MP (75.3%), CAZ (72.5%), AZT (67.5%), IP (64.8%), GN (64.0%), and CIP (56.0%). Ambulatory isolates presented susceptibility superior to 90%, except for GN (81.6%) and CIP (75.7%). During these years the susceptibilities to most important b lactams (IP, MP and CAZ) had diminished; activity of IP decreased 10.5%, MP 8.0%, CAZ 7.3%, and among nosocomial isolates the decrease was greater: IP 15.4%, MP 13.0% and CAZ 10.3%. TZP fortunately sustained the activity along time.

Conclusion: Appropriate empirical treatments based on knowledge of particular resistance patterns are important determinants of the success of therapeutics, therefore studies of surveillance can be helpful in fighting the development and spread of resistance.

Session Details

Date: 10/04/2010
Time: 00:00-00:00
Session name: Abstracts 20th European Congress of Clinical Microbiology and Infectious Diseases
Location: Vienna, Austria, 10 - 13 April 2010
Presentation type:
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