Observations of resistance through minimum inhibitory concentrations trends for respiratory specimens of commonly isolated organisms

• Published in: American journal of health-system pharmacy Vol. 73 Suppl 1; no. 5 Suppl 1; pp. S42 - S48
• Main Authors: Gillard, Christopher J, Al-Dahir, Sara, Brakta, Fatima
• Format: Journal Article
• Language: English
• Published: England Copyright American Society of Health-System Pharmacists, Inc. All rights reserved 01.03.2016; Oxford University Press
• Subjects: Acinetobacter - drug effects; Acinetobacter - isolation & purification; Acinetobacter - physiology; Anti-Bacterial Agents - pharmacology; Anti-Bacterial Agents - therapeutic use; Ciprofloxacin - pharmacology; Ciprofloxacin - therapeutic use; Dose-response relationship; Drug Resistance, Bacterial - drug effects; Drug Resistance, Bacterial - physiology; Health aspects; Humans; Imipenem - pharmacology; Imipenem - therapeutic use; Intensive Care Units - trends; Microbial drug resistance; Microbial Sensitivity Tests - methods; Microbial Sensitivity Tests - trends; Observations; Pathogenic bacteria; Pharmacological research; Pseudomonas aeruginosa - drug effects; Pseudomonas aeruginosa - isolation & purification; Pseudomonas aeruginosa - physiology; Respiratory Tract Infections - drug therapy; Respiratory Tract Infections - microbiology; Retrospective Studies; Staphylococcus aureus - drug effects; Staphylococcus aureus - isolation & purification; Staphylococcus aureus - physiology; Testing; Vancomycin - pharmacology; Vancomycin - therapeutic use; Virulence (Microbiology)
• ISSN: 1079-2082; 1535-2900
• DOI: 10.2146/sp150032

OBJECTIVE.The objective of this study was to determine minimum inhibitory concentration (MIC) trends among common bacterial organisms found in respiratory isolates in the trauma intensive care unit setting. METHODS.In this retrospective observational study, MIC data was reviewed over a three year period from January 2009 to December 2011 for the three most frequently identified organisms isolated from respiratory specimens in a trauma intensive care unit along with corresponding hospital data. RESULTS.The most frequently isolated bacterial species identified were Staphylococcus aureus (229 isolates), Pseudomonas aeruginosa (129 isolates), and Acinetobacter species (87 isolates) in the analysis within our institution from 2009-2011. There was considerable variability among the MIC trends for the analyzed organisms. For Pseudomonas isolates, observed sensitivities were as high as 100% for antibiotics ciprofloxacin and imipenem in 2009, but decreased over the next two years in 2010 and 2011. There was considerable variability among the MIC trends for Acinetobacter over the three year period for the antibiotics tested. The MIC data for most Staphylococcus aureus isolates over the three years were sensitive to vancomycin with little change in the observed MIC data. CONCLUSION.The data reported is observational and indicates the need for future studies to establish a valid relationship of the MIC data over time in our institution particularly among our gram negative organisms, to monitor patterns of antimicrobial resistance.