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Background Multidrug resistant Acinetobacter baumanii (MRAB) is an emerging pathogen that is an important cause of hospital acquired infection and has been shown to increase mortality and length of hospital stay. MRAB is the predominant multidrug resistant bacteria at Nashville General Hospital at Meharry Medical College (NGHM). The goal of this study is to determine the major genomic and proteomics patterns of MRAB at NGHM.

Background Two hundred and forty-seven isolates of Acinetobacter baumanii (AB) were identified in the Nashville General Hospital at Meharry epidemiology database for a three year period. Of these isolates, 77% were multi-drug resistant (MRAB). Mechanical ventilation and multiple site recovery were associated with MRAB, and MRAB isolates were associated with increased mortality relative to sensitive AB isolates [1]. AB acquires resistance rapidly and the mechanisms are still being identified. Proteomic analysis can identify proteins that change in their expression levels in the presence of antibiotics, a possible mechanism of resistance for AB. No proteome databases exist for this organism so antibiotic sensitivity and resistance proteomes were generated for MRAB bronchial wash isolate MMC#4. Materials and methods AB MMC#4 was grown in plain LB broth or LB broth supplemented with MIC50 concentrations of levofloxacin, tobramycin, gentamicin, cefotaxime and meropenem. Cell pellets were lysed and total protein run on an SDS-PAGE gel. Protein bands were excised and in-gel digested with trypsin. Resulting peptides were analyzed using a Thermo Finnigan LTQ ion trap mass spectrometer equipped with a 1-D nanoLC pump (Eksigent), Nanospray source (James A Hill Company), and Xcalibur 2.0 SR2 instrument control (Thermo Scientific). Peptides were separated on a