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Dissemination of ceftazidime‐resistant Acinetobacter baumannii clonal complex 92 in Korea
Author(s) -
Lee Y.,
Bae I.K.,
Kim J.,
Jeong S.H.,
Lee K.
Publication year - 2012
Publication title -
journal of applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 1364-5072
DOI - 10.1111/j.1365-2672.2012.05283.x
Subject(s) - ceftazidime , acinetobacter baumannii , multilocus sequence typing , microbiology and biotechnology , biology , integron , acinetobacter , gene , insertion sequence , transposable element , antibiotic resistance , genetics , genotype , pseudomonas aeruginosa , antibiotics , bacteria , genome
Aims: This study was performed to describe the epidemiological traits of ceftazidime‐resistant Acinetobacter baumannii clinical isolates from Korea. Methods and Results: Antimicrobial susceptibilities were determined by disk diffusion assay. PCR experiments were performed to detect genes encoding extended‐spectrum β‐lactamases and metallo‐β‐lactamases. Detection of IS Aba1 upstream of the bla ADC gene was also performed by PCR amplification. The genetic organization of the bla PER‐1 gene was investigated by PCR mapping and sequencing of the regions surrounding the gene. Multilocus sequence typing was performed using seven housekeeping genes. A. baumannii isolates of clonal complex (CC) 92 exhibited a higher resistance rate (286/289, 99%) against ceftazidime compared to A. baumannii isolates of non‐CC92 (7/87, 8%). Amongst 286 ceftazidime‐resistant isolates of CC92, 100 (35%) isolates carried the bla PER‐1 gene, while none of the 87 isolates of non‐CC92 carried the gene. The bla ADC gene associated with an IS Aba1 element was detected in 98% (281/286) of ceftazidime‐resistant isolates of CC92 and in all seven ceftazidime‐resistant isolates of non‐CC92. The bla PER‐1 gene was located on a transposon, Tn 1213 (IS Pa12 ‐ bla PER‐1 ‐Δ gst ‐IS Pa13 ), in 95 isolates and on a complex class 1 integron ( orf513 ‐ bla PER‐1 ‐putative ABC transporter gene) in five isolates. Southern blot experiments confirmed the chromosomal location of the bla PER‐1 gene. Conclusions: Acinetobacter baumannii CC92 which has acquired ceftazidime resistance by the production of PER‐1 extended‐spectrum β‐lactamases and/or the overproduction of Acinetobacter ‐derived cephalosporinase is widely disseminated in Korea. Significance and Impact of the Study: This study shows the mechanisms of acquiring ceftazidime resistance in A. baumannii and the epidemiological traits of ceftazidime‐resistant A. baumannii isolates from Korea.