Impact of Use of Multiple Antimicrobials on Changes in Susceptibility of Gram-Negative Aerobes

• Published in: Clinical infectious diseases Vol. 28; no. 5; pp. 1017 - 1024
• Main Authors: Friedrich, Lawrence V., White, Roger L., Bosso, John A.
• Format: Journal Article
• Language: English
• Published: Chicago, IL The University of Chicago Press 01.05.1999; University of Chicago Press
• Subjects: Adult; Aerobic bacteria; Anti-Bacterial Agents; Antibacterial agents; Antibiotic Prophylaxis; Antibiotic resistance; Antibiotics; Antibiotics. Antiinfectious agents. Antiparasitic agents; Antimicrobials; Biological and medical sciences; Cephalosporins; Clinical Articles; Dosage; Drug dependence; Drug Resistance, Microbial; Drug Therapy, Combination - adverse effects; Drug Therapy, Combination - therapeutic use; Drug Utilization; Female; Fluoroquinolones; Gram-Negative Bacteria - drug effects; Gram-Negative Bacterial Infections - drug therapy; Humans; Linear Models; Linear regression; Male; Medical sciences; Microbial Sensitivity Tests; Penicillin; Pharmacology. Drug treatments; Treatment Failure; Pseudomonadales; Enterobacter cloacae; Drug susceptibility test; Escherichia coli; Use; Neisseriaceae; Hospital strain; Enterobacter aerogenes; Epidemiology; In vitro; Acinetobacter baumannii; Antibiotic; Risk factor; Serratia marcescens; Bacteria; Micrococcales; Pseudomonadaceae; Pseudomonas aeruginosa; Proteus mirabilis; Antibacterial agent; Klebsiella pneumoniae; Enterobacteriaceae; Gram negative bacteria
• ISSN: 1058-4838; 1537-6591
• DOI: 10.1086/514747

Evaluation of antimicrobial usage vs. susceptibility relationships typically involves single agents. However, susceptibility profiles may be affected by multiple drugs. From 1992 through 1996, we studied relationships between drug usage and the susceptibility (only susceptibility rates of ⩾70%) of Acinetobacter anitratus (baumannii), Enterobacter aerogenes, Escherichia coli, Enterobacter cloacae, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis, and Serratia marcescens to 22 agents. Linear regression was used to assess usage of each agent vs. susceptibility to it and to all agents. Only relationships with a coefficient of determination of ⩾0.5 and a negative slope were evaluated and classified as increasing drug use and decreasing susceptibility (↑D, ↓%S) or decreasing drug use and increasing susceptibility (↓D, ↑%S). The mean numbers (range) of drugs associated with a change in susceptibility were 1.7 (0–14) and 0.6 (0–7), respectively, for ↑D, ↓%S and ↓D, ↑%S relationships. Multiple antimicrobials are associated with susceptibility to other drugs; thus, surveillance of these relationships should not be limited to single drugs.