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Control of multi-resistant bacteria and ventilator-associated pneumonia: is it possible with changes in antibiotics?
Elisa M Jukemura1, Marcelo N Burattini, Carlos A P Pereira
1Infectious Diseases Division, Internal Medicine Department, School of Medicine, Federal University of São Paulo, Brazil. elisricardo@hotmail.com
Abstract:
Potent antimicrobial agents have been developed as a response to the development of antibiotic-resistant bacteria, which especially affect patients with prolonged hospitalization in Intensive Care Units (ICU) and who had been previously treated with antimicrobials, especially third-generation cephalosporins. This study was to determine how changes in the empirical treatment of infections in ICU patients affect the incidence of Gram-negative bacteria species and their susceptibility to antimicrobials, and examine the impact of these changes on nosocomial infections. A prospective interventional study was performed in a university hospital during two periods: 1) First period (September 1999 to February 2000); and 2) Second period (August 2000 to December 2000); empirical treatment was changed from ceftriaxone and/or ceftazidime in the first period to piperacillin/tazobactam in the second. ICU epidemiological and infection control rates, as well as bacterial isolates from upper airways were analyzed. Ceftazidime consumption dropped from 34.83 to 0.85 DDD/1000 patients per day (p=0.004). Piperacillin/tazobactam was originally not available; its consumption reached 157.07 DDD/1000 patients per day in the second period (p=0.0002). Eighty-seven patients and 66 patients were evaluated for upper airway colonization in the first and second periods, respectively. There was a significant decrease in the incidence of K. pneumoniae (p=0.004) and P. mirabilis (p=0.036), restoration of K. pneumoniae susceptibility to cephalosporins (p<0.0001) and reduction of ventilator-associated pneumonia rates (p<0.0001). However, there was an increase in P. aeruginosa incidence (p=0.005) and increases in ceftazidime (p=0.003) and meropenem (p<0.0001) susceptibilities. Changing antimicrobial selective pressure on multi-resistant Gram-negative bacteria helps control ventilator-associated pneumonia and decreases antimicrobial resistance.
Insights
Changing empirical antimicrobial treatment in intensive care units (ICUs) reduced resistant Gram-negative bacteria and ventilator-associated pneumonia. This shift in antibiotic use improved bacterial susceptibility, demonstrating a strategy to combat antimicrobial resistance.
Area of Science:
- Infectious Diseases
- Clinical Pharmacy
- Critical Care Medicine
Background:
- Antibiotic-resistant bacteria pose a significant threat, particularly to intensive care unit (ICU) patients with prolonged hospital stays and prior antimicrobial exposure.
- Third-generation cephalosporins are frequently used, contributing to the selective pressure driving antimicrobial resistance in Gram-negative bacteria.
Purpose of the Study:
- To evaluate the impact of altering empirical antimicrobial treatment strategies on the incidence and antimicrobial susceptibility of Gram-negative bacteria in ICU patients.
- To assess the effect of these treatment changes on the rates of nosocomial infections, specifically ventilator-associated pneumonia.
Main Methods:
- A prospective interventional study was conducted in two periods, comparing empirical treatment with ceftriaxone/ceftazidime (Period 1) to piperacillin/tazobactam (Period 2).
- Analysis included ICU epidemiological data, infection control rates, and bacterial isolates from upper airway colonization.
- Antimicrobial consumption was quantified using DDD/1000 patients per day.
Main Results:
- A significant decrease in the incidence of Klebsiella pneumoniae and Proteus mirabilis was observed (p=0.004 and p=0.036, respectively).
- Restoration of K. pneumoniae susceptibility to cephalosporins (p<0.0001) and a reduction in ventilator-associated pneumonia rates (p<0.0001) were achieved.
- An increase in Pseudomonas aeruginosa incidence (p=0.005) was noted, alongside increased susceptibility to ceftazidime and meropenem.
Conclusions:
- Modifying empirical antimicrobial selective pressure effectively controls ventilator-associated pneumonia in ICUs.
- Strategic changes in antibiotic selection can decrease the prevalence of multi-resistant Gram-negative bacteria and mitigate antimicrobial resistance.
- The study highlights the dynamic relationship between antimicrobial use patterns and bacterial resistance profiles in critical care settings.
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