Introduction: Species from the Acinetobacter genus, not only Acinetobacter baumannii, have become epidemic nosocomial pathogens of great concern in recent years. The emergence of multi-drug resistant A. baumannii and the detection of carbapenem resistant clones of A. pittii and A. nosocomialisin clinical settings establish the need to find new antimicrobial targets for future treatment of infections caused by this genus. The expression of efflux pumps plays a major role in antibiotic resistance but they might also be involved in virulence and pathogenicity. An exhaustive characterization of these mechanisms will contribute to a better understanding of the pathogenic processes and virulence mechanisms of these microorganisms.

 

Objectives: Determine the role of efflux systems and outer membrane proteins of Acinetobacter spp. in resistance and virulence by two approaches: (i) Create a llibrary of knock-out mutants from two clinical isolates in efflux pumps and OMPs; (ii) Characterise a collection of clinical isolates ofAcinetobacter spp. to determine a relationship between presence of efflux mechanisms, antimicrobial susceptibility and virulence. 

 

Methodology: To obtain knock-out mutants we have performed an allelic replacement mutagenesis protocol. For the characterisation of the clinical isolates, PCRs for efflux genes and MICs were performed.