Epidemiology of evolution and antibiotic resistance profile of Acinetobacter baumannii and Pseudomonas aeruginosa in a Greek tertiary care hospital

Abstract number: 1734_28

Protonotariou E., Vitti D., Tsivitanidou M., Sofianou D.

Objectives: Infections with Pseudomonas aeruginosa (P. aeruginosa) and Acinetobacter baumannii (A. baumannii) are of great concern for hospitalised patients, especially with multidrug-resistant strains. The aim of the present study was to determine the evolution of infections caused by these bacteria and to define current and microbial susceptibility profile for a period of 7 year in our hospital.

Methods: Data was collected from patients admitted in Hippokration General Hospital and infected either with A. baumannii or P. aeruginosa. Bacterial identification and susceptibility testing were achieved using the VITEK 1 automated system (bioMérieux, France) for the period 1999–2001 and VITEK 2 for the period 2002–2005. Ceftazidime (CAZ), imipenem (IMP), ciprofloxacin (CIP), amikacin (AN) and the combination piperacillin/tazobactam (PIP/TAZ) were tested.

Results: During the 7 year-time period a total of 7148 strains were reviewed. The study comprised of 2382 A. baumannii and 4766 of P. aeruginosa strains collected from wounds, bronchial secretions, blood, urine, catheter tips and other clinical specimens. About A. baumannii, the number of strains isolated ranged from 165 to 526 during 1999–2005. In the same period, the antibiotic resistance rates (ARR) of CAZ, CIP, PIP/TAZ and AN were quite high, from 77 to 90%. The resistance rate of IMP increased significantly from 22% in 1999 to 74% in 2005 (p < 0.001).

The number of P. aeruginosa isolates was between 513 and 840 and the ARR to the tested antimicrobial agents ranged from 11 to 40%. About IMP, the ARR never exceeded 30%.

Conclusions: Our study showed quite high resistance rates of CAZ, CIP, PIP/TAZ and AN to A. baumannii throughout our study's period. During the same period the ARR to IMP increased significantly. On the other hand, the resistance of the above agents to P. aeruginosa increased slightly and in some cases like in piperacillin/tazobactam even decreased. The high rates of antimicrobial resistance, especially, of A. baumannii to the tested antibiotics indicate that a) the broad use of these drugs needs to be revised b) continuous surveillance studies in order to observe changes in resistance of isolates which might help therapeutic choices are necessary.

Session Details

Date: 31/03/2007
Time: 00:00-00:00
Session name: European Society of Clinical Microbiology and Infectious Diseases
Location: ICC, Munich, Germany
Presentation type:
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