Related Experiment Video
Updated: Sep 29, 2026
Antibiotic Efficacy Testing in an Ex vivo Model of Pseudomonas aeruginosa and Staphylococcus aureus Biofilms in the Cystic Fibrosis Lung
Published on: January 22, 2021
Consumption of imipenem correlates with beta-lactam resistance in Pseudomonas aeruginosa
Philipp M Lepper1, Eberhard Grusa, Helga Reichl
1Section of Hospital Hygiene, Department of Medical Microbiology and Hygiene, Ulm University Hospital, Germany.
Abstract:
It is generally assumed that the antibiotic prescription policy of a hospital has a significant impact on bacterial resistance rates; however, few studies are available to support this concept with valid statistical data. During a 3-year period from 1997 to 2000, we monitored the consumption of beta-lactam and other antibiotics with known activity against Pseudomonas aeruginosa in a 600-bed community hospital. Monthly isolations of P. aeruginosa were assessed, and resistance rates were recorded. Partial correlation coefficients between consumption and resistance rates were determined, taking into account possible associations with other variables such as seasonal effects and transfers from other hospitals. A total of 30 +/- 7 novel P. aeruginosa strains per month were isolated without epidemic clustering. Prescriptions of imipenem varied significantly during the study period, while prescriptions of other antipseudomonal agents were stable, with the exception of an increase in piperacillin-tazobactam prescriptions. Rates of resistance of P. aeruginosa to the antimicrobial agents used showed a time course similar to figures for imipenem consumption. Monthly rates of resistance to imipenem (partial correlation coefficient [cc], 0.63), piperacillin-tazobactam (cc, 0.57), and ceftazidime (cc, 0.56) were significantly associated with imipenem prescription rates in the same or the preceding month, while consumption of ceftazidime or piperacillin-tazobactam had no apparent association with resistance. Among the variables investigated, imipenem consumption was identified as the major factor associated with both carbapenem and beta-lactam resistance in endemic P. aeruginosa. Periods of extensive imipenem use were associated with significant increases in resistance. Our data support the concept that a written antibiotic policy which balances the use of various antibiotic classes may help to avoid disturbances of a hospital's microbial sensitivity patterns.
Insights
Hospital antibiotic policies significantly impact bacterial resistance. This study found imipenem use strongly correlated with increased Pseudomonas aeruginosa resistance, highlighting the need for balanced antibiotic stewardship to maintain microbial sensitivity patterns.
Area of Science:
- Medical Microbiology
- Infectious Diseases
- Hospital Epidemiology
Background:
- Hospital antibiotic prescription policies are widely believed to influence bacterial resistance rates.
- However, robust statistical data directly linking policies to resistance, particularly for specific pathogens like Pseudomonas aeruginosa, remains limited.
Purpose of the Study:
- To statistically evaluate the impact of antibiotic consumption on resistance rates of Pseudomonas aeruginosa.
- To identify specific antibiotic agents whose usage patterns correlate with resistance development in a community hospital setting.
Main Methods:
- A 3-year observational study (1997-2000) in a 600-bed hospital.
- Monitored monthly consumption of beta-lactam and antipseudomonal antibiotics.
- Assessed monthly P. aeruginosa isolations and recorded resistance rates.
- Utilized partial correlation coefficients to analyze associations between antibiotic consumption and resistance, controlling for seasonality and patient transfers.
Main Results:
- Imipenem consumption varied significantly, while other antipseudomonal agents remained stable, except for piperacillin-tazobactam.
- P. aeruginosa resistance rates to imipenem, piperacillin-tazobactam, and ceftazidime showed a temporal correlation with imipenem prescription rates.
- Imipenem consumption was identified as the primary driver for both carbapenem and beta-lactam resistance in endemic P. aeruginosa.
Conclusions:
- Increased imipenem usage was directly associated with significant rises in P. aeruginosa resistance.
- Hospital antibiotic policies that judiciously balance the use of different antibiotic classes are crucial for preserving microbial sensitivity patterns.
Related Concept Videos
01:30Development of Antibiotic Resistance
01:25Clinical Significance of Antibiotic Resistance
01:25Mechanism of Antibiotic Resistance in MRSA
01:23Inhibitors of Gram-positive Cell Wall Synthesis
01:14Atypical Pneumonia
01:27Production of Antibiotics