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An Affordable HIV-1 Drug Resistance Monitoring Method for Resource Limited Settings
Published on: March 30, 2014
Resistance Patterns and Optimization of Empirical Therapy for Urinary Tract Infections in Patients on
Kyohei Sugiyama1, Keita Hirai2,3, Madoka Kibe1
1Department of Clinical Pharmacology and Genetics, University of Shizuoka, Shizuoka, Japan.
Abstract:
Background: Trimethoprim-sulfamethoxazole (SXT) is widely used for Pneumocystis pneumonia prophylaxis. However, prolonged use may induce antimicrobial resistance, potentially compromising empirical therapy for urinary tract infections (UTIs). Methods: We retrospectively analyzed 3,525 patients with positive urine cultures at Shizuoka General Hospital (2018-2023). Among them, 149 received SXT prophylaxis. Antimicrobial susceptibility and the relationship between prophylaxis duration and resistance were evaluated. Results: Escherichia coli and Klebsiella pneumoniae were the most common pathogens. In the SXT prophylaxis group, E. coli susceptibility to SXT was significantly reduced (21.2% vs. 87.4%). Susceptibility to other antibiotics also declined, including ampicillin (31.2% vs. 71.6%), piperacillin (32.5% vs. 74.8%), levofloxacin (57.5% vs. 74.7%), and ciprofloxacin (56.2% vs. 74.1%). Susceptibility to expanded-spectrum cephalosporins, including second-, third-, and fourth-generation agents remained preserved. Receiver operating characteristic analysis identified a prophylaxis duration >406 days as predictive of SXT resistance (area under the curve 0.82, sensitivity 94%, and specificity 60%). Short-term prophylaxis (≤30 days) mitigated resistance, although E. coli susceptibility to SXT was still limited (47.8%). Conclusions: Prophylactic SXT use markedly reduces susceptibility to multiple antibiotics, especially penicillins and fluoroquinolones. Resistance correlates with prophylaxis duration. For empirical UTI therapy, intravenous expanded-spectrum cephalosporins may be preferable.
Insights
Prolonged trimethoprim-sulfamethoxazole (SXT) prophylaxis for Pneumocystis pneumonia increases antimicrobial resistance, especially in E. coli. Longer SXT use duration predicts resistance, impacting urinary tract infection treatment.
Area of Science:
- Infectious Diseases
- Clinical Pharmacy
- Antimicrobial Stewardship
Background:
- Trimethoprim-sulfamethoxazole (SXT) is a common prophylactic agent for Pneumocystis pneumonia.
- Prolonged SXT use may lead to antimicrobial resistance, potentially affecting empirical treatment of urinary tract infections (UTIs).
- Understanding the impact of SXT prophylaxis on bacterial susceptibility is crucial for effective patient care.
Purpose of the Study:
- To evaluate the effect of trimethoprim-sulfamethoxazole (SXT) prophylaxis on antimicrobial susceptibility patterns.
- To determine the relationship between the duration of SXT prophylaxis and the development of antimicrobial resistance.
- To inform empirical therapy choices for urinary tract infections in patients receiving SXT prophylaxis.
Main Methods:
- Retrospective analysis of 3,525 patients with positive urine cultures (2018-2023).
- Focus on 149 patients receiving SXT prophylaxis for Pneumocystis pneumonia.
- Evaluation of antimicrobial susceptibility and correlation with prophylaxis duration using ROC analysis.
Main Results:
- SXT prophylaxis significantly reduced E. coli susceptibility to SXT (21.2%) and other antibiotics like ampicillin and fluoroquinolones.
- Prophylaxis duration exceeding 406 days was a strong predictor of SXT resistance (AUC 0.82).
- Short-term prophylaxis (≤30 days) showed reduced resistance, but E. coli susceptibility to SXT remained limited (47.8%).
Conclusions:
- Prophylactic SXT use markedly decreases susceptibility to multiple antibiotics, particularly penicillins and fluoroquinolones.
- Antimicrobial resistance is directly correlated with the duration of SXT prophylaxis.
- Intravenous expanded-spectrum cephalosporins may be a preferred empirical treatment for UTIs in this patient population.
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