Streptococcus pneumoniae, Haemophilus influenzae, Klebsiella pneumoniae, and Pseudomonas aeruginosa are among the primary bacterial etiologic pathogens identified in nosocomial respiratory tract infections. The ARM Program (www.armprogram.com) is an ongoing project to document trends in antimicrobial susceptibility patterns and identify relationships between antibiotic use and resistance rates.
Antibiograms/sensitivity reports from 1995-2003 (1997 for levofloxacin and cefepime) were analyzed from the ARM surveillance database, which contains susceptibility results on 24.1 million inpatient/outpatient isolates (19 organisms/48 antibiotics) collected from 314 US institutions. S pneumoniae isolates were reviewed for resistance to penicillin, cefuroxime, ceftriaxone, and levofloxacin; H influenzae to ampicillin and ceftriaxone; K pneumoniae to cefotaxime, ceftriaxone, cefepime, ciprofloxacin, and levofloxacin; and P aeruginosa to ceftazidime, cefepime, ciprofloxacin, levofloxacin, gentamicin, tobramycin, and imipenem.
Between 1995-2003, S pneumoniae resistance to penicillin increased 6.5% and to levofloxacin, 1.9%; resistance decreased 14.9% to cefuroxime and 27.9% to ceftriaxone. For H influenzae, resistance to ampicillin increased 11.6% and to ceftriaxone, 1.3%. For K pneumoniae, resistance to cefotaxime increased 5.4%; to ceftriaxone, 3.6%; cefepime, 3.6%; ciprofloxacin, 3.4%; levofloxacin 3.3%. P aeruginosa resistance to ceftazidime increased 16.2%; to cefepime, 1.4%; ciprofloxacin, 15.5%; levofloxacin, 2.3%; gentamicin, 16.1%; tobramycin, 10.2%; and imipenem, 10.7%.
The prevalence of resistance among nosocomial pathogens to commonly prescribed antibiotics increased between 1995 and 1998, with the exception of S pneumoniae to ceftriaxone and cefuroxime, which both showed a decline in resistance.
Use of ARM Program data enables institutions to delineate occurrence and extent of antimicrobial resistance, allowing strategic intervention and the potential to reduce costs of antibiotics associated with inappropriate use.
J.G. Gums, Aventis Pharmaceuticals, Wyeth Pharmaceuticals, Roche Pharmaceuticals, Pfizer Pharmaceuticals