1776. Co-coloznization with Neisseria species is a risk factor for prolonged colonization with multidrug resistant Acinetobacter baumannii in the respiratory tract
Session: Poster Abstract Session: Resistant Gram-Negative Infections: Acinetobacter
Saturday, October 10, 2015
Room: Poster Hall
  • PosterKitazawav32.pdf (136.3 kB)
  • Background: Multidrug-resistant (MDR) Acinetobacter baumannii  colonization increases the risk of the spread in hospitals. One strategy for shortening the colonization period has been considered as antibiotic disuse, although the impact of clinical factors on prolongation of MDR Acinetobacter baumannii colonization has not been investigated. We investigated the association between prolongation of MDR Acinetobacter baumanniicolonization and clinical factors.

    Methods: All the patients from whose respiratory tract MDR Acinetobacter baumannii were cultured from August 2009 to March 2012 in our hospital were enrolled. Colonization period was defined as the number of days from the first detection through the first disappearance. A long term colonizer and a short term colonizer were defined as a patient whose colonization period is longer than 30 days, and 30 days or shorter, respectively. Patients in whom MDR Acinetobacter baumanniiwere colonized persistently until they died or those who were lost to follow up within 30 days were excluded. Clinical data were abstracted from medical records.

    Results: MDR Acinetobacter baumannii colonized in 34 patients. The median duration of MDRAB colonization was 17.5 days (range, 3-584 days). The clearance rate of colonization gradually decreased during their colonization periods; the colonization rate was 62.4% at the 30 days (N=9), and 7.6% at the 90 days, respectively (Fig. 1). Long term colonizers were nine and short term colonizers were 13. Twelve patients were excluded due to undetermined colonization periods. There were no significant differences in the average leukocyte counts, the numbers of used antibiotic classes and durations of antibiotic use, and the rate of central catheterization and mechanical ventilation between the two colonizers. Long term colonizers carried Neisseria species more frequently in the 30 days than short colonizers (7/13 vs 1/9, p=0.01). The colonization rates with MDR Acinetobacter baumanniiin Neisseria negative patients and Neisseria positive patients at the 90 days were 10.0% and 83.3%, respectively (P=0.004) (Fig. 2). 

    Conclusion: Prolonged colonization with MDR Acinetobacter baumannii in the respiratory tract was associated with Neisseria species co-colonization, but not with use of antibiotics and medical deivices.

    Takatoshi Kitazawa, M.D.1, Kazunori Seo, M.D.1, Ichiro Koga, M.D.1 and Yasuo Ota, M.D.2, (1)Infectious Diseases, Teikyo University School of Medicine, Tokyo, Japan, (2)Internal Medicine, Teikyo University, School of Medicine, Tokyo, Japan


    T. Kitazawa, None

    K. Seo, None

    I. Koga, None

    Y. Ota, None

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