1780. Clinical and microbiological characteristics of Acinetobacter lwoffii bacteremia compared with Acinetobacter baumannii
Session: Poster Abstract Session: Resistant Gram-Negative Infections: Acinetobacter
Saturday, October 10, 2015
Room: Poster Hall
Posters
  • alwoffii_bsiIDW15_09252015.pdf (165.0 kB)
  • Background: There is interest in members of the Acinetobacter genus as cause of nosocomial infections.  We aim to compare the clinical and microbiological characteristics of bacteremia due to Acinetobacter lwoffii, with those of bacteremia due to Acinetobacter baumannii.

    Methods: Case-control study of consecutive patients with >=1 blood culture positive for A. lwoffii, from 01/01/2005 to 12/31/2011. Controls were patients with at least one blood culture positive for A. baumannii and matched based on blood culture date (month and year) on a 1:1 ratio.  Baseline demographics, microbiological characteristics, and treatments administered were obtained. Multidrug resistance was defined as resistance to at least one antibiotic within three different antibiotic classes. Source of infection was defined using CDC criteria. Differences in proportions were analyzed using the X2 or Fisher exact test accordingly. Difference in means and medians were analyzed using student-t tests and non-parametric tests, respectively.

    Results: 17 cases of A. lwoffii bacteremia and 17 controls were identified. Mean SOFA score among cases was 3.43.9versus 7.75.7 among controls (P=0.02).  Cases had community onset bacteremia 65% (OR 2.62; CI 0.65-10.5; P=0.17). A. lwoffii isolates were less likely to be multidrug resistant than A. baumannii (OR 0.17; CI 0.04-0.76; P=0.02). Blood cultures with A. lwoffii were more likely to be polymicrobial (OR 5.96; CI 1.33-26.7; P=0.01). Drug resistance patters based on nosocomial vs community onset of bacteremia are seen in Table 1. No differences were found in source of infection or mortality.

    Conclusion: Patients with A. lwoffii bacteremia had lower SOFA scores on the day of the event, bacteremia was more likely to be polymicrobial and less likely to be multidrug resistant when compared to A. baumannii bacteremia.

    Table 1. Proportion of multidrug resistant isolates of Acinetobacter baumannii and Acinetobacter lwoffii in nosocomial onset versus community-onset bacteremia

    Nosocomial Onset

    Community Onset

    Acinetobacter lwoffii  n=17 (%)

    Multidrug resistant

    4 (23.5)

    1(5.9)

    Non-multidrug resistant

    2(11.8)

    10(58.8)

    Acinetobacter baumannii n=17 (%)

    Multidrug resistant

    9(52.9)

    1(5.9)

    Non-multidrug resistant

    1(5.9)

    4(23.5)

    Total

    18

    16

    Rossana Rosa, MD, Department of Medicine, Jackson Memorial Hospital-University of Miami Miller School of Medicine, Miami, FL, John Mills, MD, Division of Infectious Diseases, University of Pennsylvania, Philadelphia, PA and L. Silvia Munoz-Price, MD, PhD, Institute for Health and Society, Medical College of Wisconsin, Milwaukee, WI

    Disclosures:

    R. Rosa, None

    J. Mills, None

    L. S. Munoz-Price, None

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