Question

Acinetobacter baumannii is an opportunistic pathogen (meaning it takes advantage of a disruption in the host’s immune system) that causes severe respiratory infections. A disturbing finding suggests that this pathogen expresses a siderophore-mediated iron acquisition system and these genes may be part of a mobile genetic element. Why is this observation of concern?

Answer 1

Few studies have indicated that the spread of a limited number of successful clonal lineages has resulted in the globally increased prevalence of A. baumannii. These findings specifically concern the multidrug resistant A. baumannii (MDRAB) isolates. The clonal relationship between Acinetobacter isolates can be investigated using techniques such as variable number tandem repeats (VNTR) analysis multi locus VNTR analysis, sequence analysis of the 16S rDNA gene, multi locus sequence typing (MLST), restriction analysis of the complete genome using pulse field gel electrophoresis (PFGE), amplified 16SrDNA restriction analysis (ARDRA) and amplified fragment length polymorphism (AFLP) . Recently, the accessory enome has been partially determined using the fully sequenced A. baumannii strains as a backbone and etermination of the presence or absence of genes within this highly variable genomic fraction was utilised as a tool to investigate the clonal relationship of A. baumannii strains. The genotypic profiles obtained with the techniques described above can also be used for identification of Acinetobacter species when compared to the appropriate reference strain.