205. Fluoroquinolone- and Ceftriaxone-Based Therapy of Community-Acquired Pneumonia (CAP) in Hospitalized Patients (pts) and the Risk of Subsequent Colonization and Infection with Multidrug-Resistant (MDR) Organisms
Session: Poster Abstract Session: Antimicrobial Resistance: Clinical Studies
Friday, October 21, 2011
Room: Poster Hall B1
Background: Current practice guidelines recommend a respiratory fluoroquinolone or a β-lactam plus a macrolide as first-line therapies for adult pts admitted with CAP to a non-intensive care unit. Few comparative data exist on the rates of subsequent colonization or infection with MDR organisms in these patients.

Methods: A retrospective cohort study was performed on all adult pts who were newly hospitalized with CAP between 3/10 and 10/10 and were treated with either moxifloxacin (MOX) or ceftriaxone plus azithromycin (CEFA). Zero time (ZT) was defined as the day therapy was started. Pts with MDR organisms isolated prior to ZT, pts admitted within the previous three months, and residents of a nursing home or a long-term care facility were excluded. Pts treated with MOX were compared to pts treated with CEFA with regard to a variety of demographic and clinical characteristics. The primary outcome was the subsequent colonization or infection with methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), gram-negatives resistant to >3 drug classes (GNR), or Clostridium difficile (Cdiff) within the next six months.

Results: A total of 153 pts were included according to our study criteria. The median age was 65 years, 72 (47%) were male. The median CURB-65 score was 2, and the median Charlson comorbidity score was 2. 121 (79%) pts were treated with CEFA, and 32 (21%) pts were treated with MOX. Both cohorts were very similar with regard to a variety of characteristics including age, CURB-65 score, underlying comorbidities, and cure rates (P>0.2). MDR organisms (MRSA:n=7; VRE:n=1; GNR:n=5; Cdiff:n=2) were isolated from 7 (22%) MOX-treated pts and 7 (6%) CEFA-treated pts at a median of 32 days after ZT (P=0.01). Clinical infections were diagnosed in 4 (29%) of these 14 pts with cultures positive for MDR organisms. MOX therapy [OR 4.40, 95% C.I. (1.34-14.43); P=0.015] and duration of hospital stay (P=0.023) were independent predictors of subsequent isolation of MDR organisms on logistic regression analyses.

Conclusion: CAP pts treated with MOX or CEFA were very similar with regard to important clinical characteristics. However, MOX therapy was an independent predictor of subsequent colonization or infection with MDR organisms.


Subject Category: A. Antimicrobial agents and Resistance

Robert C. Goldstein, Sasha Lalite, Donna Mildvan, David C. Perlman, Tomasz Jodlowski and Jorg Ruhe, Beth Israel Medical Center, New York, NY

Disclosures:

R. C. Goldstein, None

S. Lalite, None

D. Mildvan, None

D. C. Perlman, None

T. Jodlowski, None

J. Ruhe, None

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