Search

In total, 96 carbapenem-resistant isolates of Acinetobacter baumannii were obtained from 25 hospitals in 17 European countries. Imipenem MICs ranged from <4 to 128 mg/L on retesting by Etest, with MICs ≥16 mg/L being associated with the carriage of genes encoding at least one other class D carbapenemase in addition to the intrinsic OXA-51-like enzyme. Molecular typing results obtained by random amplified polymorphic DNA analysis, followed by pulsed-field gel electrophoresis (PFGE) of ApaI-digested chromosomal DNA, were highly congruent, with 17 different PFGE types being delineated at a cut-off similarity level of 85%. With few exceptions, multiple isolates from a single hospital belonged to the same PFGE type. Seven sequence groups were identified among the 96 A. baumannii isolates, with the majority of isolates ( n = 81) belonging to the previously defined sequence groups 1 and 2, which each included eight PFGE types. These two multinational lineages included the previously defined European clones II and I, respectively, but the problem of resistant A. baumannii in Europe appeared not to be confined solely to these two European clones. Rather, two broader lineages of carbapenem-resistant A. baumannii now seem to be spreading throughout Europe. [ABSTRACT FROM AUTHOR]

The aim of the study was to investigate the genetic diversity of Acinetobacter baumannii clinical strains that had previously been allocated to three major groups based on automated ribotyping. Forty-seven isolates from European hospitals and one isolate from a South African hospital, geographically representative of the three ribogroups (ribogroups 1, 2 and 3 with 10, 23 and 15 isolates, respectively), were analysed using the highly discriminatory fingerprinting methods AFLP and pulsed-field gel electrophoresis (PFGE). Based on AFLP data, the isolates clustered into three main groups, each corresponding to one ribogroup. Inclusion of reference strains of the previously described clones I and II, responsible for outbreaks in northwestern European hospitals, showed that ribogroups 1 and 2 correspond to clones I and II, respectively, whereas ribogroup 3 apparently represents a new clone. This clone III was found in France, The Netherlands, Italy and Spain. Clones I and II were not limited to northwestern European countries, as they were also recovered from Spain, South Africa, Poland and Italy (clone I) and from Spain, Portugal, South Africa, France, Greece and Turkey (clone II). Combined AFLP and PFGE data showed intraclonal diversity and led to the distinction of 23 different genotypes. Three genotypes, two of them belonging to clone II and one to clone III, were found in different hospitals and may correspond to subsets of isolates with a more recent clonal relationship, which emphasizes the epidemic potential of these organisms. [Copyright &y& Elsevier]