Critical Care Medicine

Skip Navigation LinksHome > September 2009 - Volume 37 - Issue 9 > Intratracheal colistin sulfate for BALB/c mice with early pn...
Critical Care Medicine:
doi: 10.1097/CCM.0b013e3181a0f8e1
Laboratory Investigations

Intratracheal colistin sulfate for BALB/c mice with early pneumonia caused by carbapenem-resistant Acinetobacter baumannii

Chiang, Shyh-Ren MD; Chuang, Yin-Ching MD; Tang, Hung-Jen MD; Chen, Chi-Chung MS; Chen, Chung-Hua MD; Lee, Nan-Yao MD; Chou, Chen-His PhD; Ko, Wen-Chien MD

Collapse Box


Objectives: To study the efficacy of intratracheal colistin sulfate therapy in a murine model of acute pneumonia caused by a clinical CRAB strain, Ab396. Colistin therapy has currently achieved a favorable outcome in patients with carbapenem-resistant Acinetobacter baumannii (CRAB) infections, but parenteral colistin may have limited therapeutic efficacy for CRAB pneumonia.

Design: A controlled, in vivo experimental study.

Setting: Research laboratory of a medical center.

Subjects: Female BALB/c mice.

Interventions: The minimal inhibitory concentrations of antibiotics were measured. Acute pneumonia was established by intratracheal inoculation with an inoculum size of 2.5 × 107 colony-forming units Ab396 plus 10% porcine mucin into the lungs of mice, verified by histopathological examinations, and then treated with or without antibiotics. Mice received intratracheal saline treatment as a control group, intraperitoneal administration (IP) imipenem/cilastatin plus sulbactam (IP IS group, 80/80 mg/kg and 40 mg/kg every 8 hrs, n = 30), IP colistin sulfate (IP CS group, 150,000 U/kg every 8 hrs, n = 30), and intratracheal colistin sulfate (intratracheal CS group, 75,000 U/kg every 8 hrs, n = 30) at 2 hrs after intratracheal inoculation of Ab396.

Measurements and Main Results: The minimal inhibitory concentrations of colistin sulfate, imipenem/cilastatin, or sulbactam for Ab396 were 2 μg/mL, 128 μg/mL, or 32 μg/mL, respectively. Compared with the mice in the control, IP IS, and IP CS groups, those in intratracheal CS group had a significantly favorable outcome at 72 hrs after infection (survival rate = 0%, 10%, 0% and 100%, respectively; all p < .001, log-rank test). Furthermore, intratracheal therapy decreased significantly the bacterial loads in the lungs and normalized the wet lung/body weight ratios in mice with acute pneumonia.

Conclusions: The intratracheal colistin sulfate therapy led to more favorable outcomes than therapies by IP colistin sulfate or imipenem/cilastatin plus sulbactam in mice with early CRAB pneumonia.

© 2009 by the Society of Critical Care Medicine and Lippincott Williams & Wilkins

Article Tools


Article Level Metrics

Search for Similar Articles
You may search for similar articles that contain these same keywords or you may modify the keyword list to augment your search.