Multi-drug Resistant Acinetobacter a major issue for Iraq troops

Link: Antimicrobial Agents and Chemotherapy.

     Military medical facilities treating patients injured in Iraq and Afghanistan have identified a large number of multi-drug resistant (MDR) Acinetobacter baumannii isolates. In order to evaluate the impact of these pathogens on patient care, we analyzed the antibiotic resistance genes responsible for the MDR phenotype in Acinetobacter spp. isolates collected from patients at the Walter Reed Army Medical Center (WRAMC). Susceptibility testing, PCR amplification of the genetic determinants of resistance, and clonality were determined. Seventy-five unique patient isolates were included in this study: 53 % were bloodstream infections, 89 % were resistant to ≥ 3 classes of antibiotics and 15 % were resistant to the nine antibiotics tested. Thirty-seven percent of the isolates were recovered from patients nosocomially infected or colonized at WRAMC. Sixteen unique resistance genes or gene families and 4 mobile genetic elements were detected. MDR A. baumannnii isolates with ≥ 8 identified resistance determinants were recovered from 49 of the 75 patients. Molecular typing revealed multiple clones with 8 major clonal types being nosocomially acquired and with more than 60 % of the isolates being related to 3 pan-European types. This report gives a "snapshot" of the complex genetic background responsible for antimicrobial resistance in Acinetobacter spp. from the WRAMC. Identifying genes associated with the MDR phenotype and defining patterns of transmission serve as a starting point to devise strategies to limit the clinical impact of these serious infections.