Molecular epidemiology of Acinetobacter baumannii bloodstream isolates obtained in the United States from 1995 to 2004 using rep-PCR and multilocus sequence typing.
Using a repetitive-sequence-based (rep)-PCR (DiversiLab), we have molecularly typed Acinetobacter nosocomial bloodstream isolates (Acinetobacter baumannii [n = 187], Acinetobacter pittii [n = 23], and Acinetobacter nosocomialis [n = 61]) obtained from patients hospitalized in U.S. hospitals over a 10-year period (1995-2004) during a nationwide surveillance study (Surveillance and Control of Pathogens of Epidemiological Importance [SCOPE]). Patterns of A. baumannii rep-PCR were compared to those of previously identified international clonal lineages (ICs) and were further investigated by multilocus sequence typing (MLST) to compare the two typing methods. Forty-seven of the A. baumannii isolates clustered with the previously defined IC 2. ICs 1, 3, 6, and 7 were also detected. The remaining 81 isolates were unrelated to the described ICs. In contrast, A. pittii and A. nosocomialis isolates were more heterogeneous, as determined by rep-PCR. Our MLST results were in good correlation with the rep-PCR clusters. Our study confirms previous data indicating the predominance of a few major clonal A. baumannii lineages in the United States, particularly IC 2. The presence in the United States of A. baumannii ICs 1, 2, and 3 from as early as 1995 suggests that global dissemination of these lineages was an early event.
Institute for Medical Microbiology, Immunology and Hygiene, University of Cologne, Cologne, Germany.
Paul G
PG
Higgins
Katharina
K
Janssen
Maximilian M
MM
Fresen
Hilmar
H
Wisplinghoff
Harald
H
Seifert
D000151:Acinetobacter Infections / Q000453:epidemiology* / Q000382:microbiology*; D040981:Acinetobacter baumannii / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D016470:Bacteremia / Q000453:epidemiology* / Q000382:microbiology*; D016000:Cluster Analysis; D005838:Genotype; D006761:Hospitals; D006801:Humans; D017720:Molecular Epidemiology; D058885:Multilocus Sequence Typing; D016133:Polymerase Chain Reaction; D014481:United States / Q000453:epidemiology