Occurrence of alert pathogens in the clinical materials and consumption of antibiotics in the ICU, in the years 2007 and 2008

Introduction

A continuous pressure of antibiotics and chemotherapeutics in ICU patients promotes isolation of multidrug-resistant (MDR) strains. Treatment of infections caused by microorganisms resistant to available drugs often results in a therapeutic failure. The purpose of this work was a retrospective comparison of the rates of isolation of particular MDR pathogen groups in 2007 vs 2008 in ICU patients hospitalised in a university hospital 11-bed reference department, and of antibiotic consumption in the analysed years.

Methods

Data concerning microbiological testing were analysed based on the WHONET software, version 5.4. The analysis rejected repeated identical culture results that did not reflect a subsequent case of infection with a given MDR pathogen, but only persistence of the same strain in a given patient.

Results

MDR pathogen stains most frequently were isolated from the bronchoalveolar lavage (BAL) material. Carbapenem-resistant Gram-negative rods represented the highest rate (62% in 2007 and 64% in 2008); these included Pseudomonas aeruginosa strains (57% and 35%, respectively). Escherichia coli (11% in 2007), Klebsiella pneumoniae (12% in 2008) and Enterobacter cloacae (9% in 2008) predominated among ESBL-producing intestinal rods. A minor increase of the rate of the ESBL(+) strains was found in 2008. Single MRSA strains were isolated in the analysis period, no VRE were cultured. The highest antimicrobial drug consumption (DDD/100 person-days) in 2007 pertained to meropenem (20.6), piperacillin/tazobactam (20.0), cephazolin and vancomycin (11.6 and 11.1). The respective values for the year 2008 were as follows: piperacillin/tazobactam (20.8), voriconazole (19.7), meropenem (14.6).

Conclusions

A 47% increase in the MDR pathogen isolation rate was found in the year 2008. MDR nonfermenting rods represent the largest therapeutic and epidemiological challenge among the isolated MDR pathogens. In the subsequent analysed year, first emergence of carbapenem-resistant Acinetobacter baumanii strains was noted.