2-DE analysis indicates that Acinetobacter baumannii displays a robust and versatile metabolism

The membrane and cytoplasmatic protein extracts were analysed separately, these analyses revealed the reproducible presence of 239 and 511 membrane and cytoplamatic protein spots, respectively. MALDI-TOF/TOF characterisation identified a total of 192 protein spots (37 membrane and 155 cytoplasmatic) and revealed that the identified membrane proteins were mainly transport-related proteins, whereas the cytoplasmatic proteins were of diverse nature, although mainly related to metabolic processes.This work indicates that A. baumannii has a versatile and robust metabolism and also reveal a number of proteins that may play a key role in the mechanism of drug resistance and virulence. The data obtained complements earlier reports of A. baumannii proteome and provides new tools to increase our knowledge on the protein expression profile of this pathogen.Acinetobacter baumannii is a Gram-negative, nonmotile, aerobic coccobacillus that is often found in health care settings. There is increasing concern as regarding the prevalence of this bacterium in hospital environments, especially in intensive care units, where it has been associated with different types of infections such as pneumonia, meningitis, bacteraemia, urinary tract infections and others [1-3]. In addition, A. baumannii has a remarkable capacity to acquire resistance to most antibiotics used in clinical practice and to cause outbreaks throughout cities, countries and even continents [4-6]. Despite the emerging awareness of the potential hazards of this bacterium, little is known about the mechanisms that operate during antibiotic resistance, virulence, or persistence strategies of A. baumannii.Genomic approaches have recently been successfully applied for A. baumannii. For instance, genomic comparison between SDF and AYE strains with the soil-living A. baylyi strain ADP1 revealed important exclusive features of each strain, which may partly explain their existence in different ecological niches [7,8]. The recently