Global spread of carbapenem-resistant Acinetobacter baumannii.
OBJECTIVE
We have investigated the molecular epidemiology and distribution of carbapenemase genes in 492 imipenem-non-susceptible Acinetobacter baumannii worldwide isolates (North and Latin America, Europe, Asia, South Africa and Australia).


METHODS
MICs were determined by broth microdilution and Etest. The presence of carbapenemase-encoding genes was investigated by PCR. Molecular epidemiology was performed by repetitive sequence-based PCR (rep-PCR; DiversiLab), sequence-type multiplex PCR and PFGE.


RESULTS
Imipenem non-susceptibility was associated with ISAba1 upstream of the intrinsic bla(OXA-51-like) or the acquired carbapenemase bla(OXA-23-like), bla(OXA-40-like) or bla(OXA-58-like). Isolates were grouped into eight distinct clusters including European clones I, II and III. European clone II was the largest (246 isolates) and most widespread group (USA, pan-Europe, Israel, Asia, Australia and South Africa).


CONCLUSIONS
The global dissemination of eight carbapenem-resistant lineages illustrates the success this organism has had in epidemic spread. The acquired OXA enzymes are widely distributed but are not the sole carbapenem resistance determinant in A. baumannii.
Higgins
Paul G
PG
Institute for Medical Microbiology, Immunology and Hygiene, University of Cologne, Goldenfelsstrasse 19-21, 50935 Cologne, Germany. paul.higgins@uni-koeln.de
Dammhayn
Cathrin
C
Hackel
Meredith
M
Seifert
Harald
H
D000151:Acinetobacter Infections / Q000382:microbiology*; D040981:Acinetobacter baumannii / Q000201:enzymology* / Q000302:isolation & purification*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001208:Asia; D001315:Australia; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000235:genetics; D015373:Bacterial Typing Techniques / Q000379:methods; D016000:Cluster Analysis; D016172:DNA Fingerprinting / Q000379:methods; D004269:DNA, Bacterial / Q000235:genetics; D005060:Europe; D006801:Humans; D007843:Latin America; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D009656:North America; D016133:Polymerase Chain Reaction; D015995:Prevalence; D013019:South Africa; D018440:beta-Lactam Resistance; D001618:beta-Lactamases / Q000096:biosynthesis* / Q000235:genetics; D047090:beta-Lactams / Q000494:pharmacology*
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D047090:beta-Lactams; D001618:beta-Lactamases; C063912:carbapenemase