1586. Description of Infections Caused by Polymyxin Resistant Enterobacteriaceae and Associated Mortality.
Session: Poster Abstract Session: Multidrug-Resistant Gram Negative Rods
Saturday, October 5, 2013
Room: The Moscone Center: Poster Hall C
Posters
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  • Background:

    The emergence of carbapenem-resistance Enterobacteriaceae (CRE) is a major threat to global health. There are few options to treat infections caused by these microorganisms and polymyxins may be the drug of choice, but resistance to polymyxins has been described. 

    Methods:

    We carried out a cohort of patients infected with CRE including polymyxin sensitive and resistant strains, in a 317-bed University Hospital from March 2011 through December 2012. MIC by microdilution for tigecycline, imipenem, polymxyn B, gentamycin and fosfomycin were performed following CLSI.  Polymxyn B resistance was defined according with EUCAST Clinical Breakpoint (MIC>2ug/ml).  PCR for KPC and PFGE were performed. Data were analyzed using EPIINFO. 

    Results:

    We analyzed 157 patients infected with K. pneumoniae in 127 (80.9%) cases, Enterobacter spp in 13 (8.3%) patients and other microorganisms in 10.8%. Underlying disease identified were respiratory disease (16.3%), politrauma (14.4%), infectious diseases (10.5%) and others (58.8%).  There were 72.1% males, 57.1% were less than 60 years old. Twenty three (14.7%) were bloodstream infection and 57 (36.5%) pneumonia. PCR for KPC was positive in 76.5% strains.  Resistance to polymyxin occurred in 26.4% cases, and among this group of patients, 85% received combinated therapy with polymyxin, aminoglycosides, tigecycline , with or without carbapenem. Six clones were identified among polymyxin B resistant strains. The MIC range from 0.25 to >128 ug/mL, summarized in table 1 .  The overall mortality of this cohort of infected patients was 62.5% and mortality considered related to infection was 37.5%. There was no difference in mortality between patients with infections caused by polymyxin resistant or sensitive strains (61.5% versus 59.3%, p = 0.47).

    Table 1: Frequency of MIC (n):

    MIC ug/mL

    0,25

    0,5

    1

    2

    4

    8

    16

    32

    64

    >128

    Nº cases

    1

    11

    56

    35

    9

    5

    9

    11

    2

    2

    Conclusion:

      Infections caused by Carbapenem Resistant Enterobacteriaceae were associated with high mortality. In 26.4% cases resistance to polymyxin B was detected, however, resistance was not associated with worse prognosis. We found multiple clones of resistant polymyxins strains.

    ClÁudia Carrilho, MD1,2, Jamile Vale, student1,2, Marsileni Pelisson, MDPharm3, Larissa Oliveira4, Ana Paula Marchi5, Cintia Grion, Phd2 and Silvia Costa, MD, PhD6, (1)Universidade Estadual de Londrina, Londrina-PR, Brazil, (2)Medical Clinic, Universidade Estadual de Londrina, Londrina-PR, Brazil, (3)Clinical Analyses, Universidade Estadual de Londrina, Londrina-PR, Brazil, (4)HOSPITAL DAS CLINICAS OF UNIVERSITY OF SAO PAULO, SAO PAULO, Brazil, (5)Hospital Das Clínicas Da Faculdade De Medicina Da Universidade De São Paulo, Sao Paulo, Brazil, (6)Hospital Das Clínicas Da Faculdade De Medicina Da Universidade De São Paulo, São Paulo, Brazil

    Disclosures:

    C. Carrilho, None

    J. Vale, None

    M. Pelisson, None

    L. Oliveira, None

    A. P. Marchi, None

    C. Grion, None

    S. Costa, None

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