Molecular typing of imipenem-resistant Acinetobacter baumannii-calcoaceticus complex in a Singapore hospital where carbapenem resistance is endemic.
OBJECTIVE
To investigate the molecular epidemiology of carbapenem-resistant Acinetobacter baumannii-calcoaceticus complex isolates in a tertiary care hospital where the prevalence of carbapenem resistance among these organisms is high.


METHODS
The study was a prospective, observational study performed during an 8-month period (May 1 through December 31, 2004). A. baumannii isolates recovered from all clinical samples during the study period were included in the study. Antibiotic susceptibility testing was performed using the disk diffusion method, and all carbapenem-resistant strains were typed by a polymerase chain reaction-based typing method.Setting. An 800-bed hospital in Singapore.


RESULTS
More than half of recovered isolates were clonally unrelated, with the remaining isolates grouped into 4 genotypes.


CONCLUSIONS
The results of the study suggest that the high prevalence of carbapenem resistance among Acinetobacter organisms in this institution is not caused by the spread of a predominant clone and that other factors may need to be investigated.
Tan
Thean Yen
TY
Department of Microbiology, Laboratory Medicine Services, Changi General Hospital, Singapore. thean_yen_tan@cgh.com.sg
Poh
Karen
K
Ng
Siew Yong
SY
D000151:Acinetobacter Infections / Q000145:classification* / Q000453:epidemiology / Q000235:genetics; D040981:Acinetobacter baumannii / Q000145:classification* / Q000187:drug effects / Q000235:genetics; D016954:Acinetobacter calcoaceticus / Q000145:classification* / Q000187:drug effects / Q000235:genetics; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002228:Carbenicillin / Q000494:pharmacology; D003428:Cross Infection / Q000145:classification / Q000453:epidemiology / Q000382:microbiology; D005838:Genotype; D006801:Humans; D015378:Imipenem / Q000494:pharmacology*; D010403:Penicillin Resistance / Q000235:genetics*; D010802:Phylogeny; D011446:Prospective Studies; D012846:Singapore / Q000453:epidemiology
D000900:Anti-Bacterial Agents; D015378:Imipenem; D002228:Carbenicillin