Molecular Characterization and Epidemiological Study of Clinical Acinetobacter baumannii

• Main Authors: Chang-Hua Chen, 陳昶華
• Other Authors: Chieh-Chen Huang
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/67401348259788032100

碩士 === 國立中興大學 === 生命科學院碩士在職專班 === 91 === The Acinetobacter baumannii was noticed since imipenem-resistant had emerged recently at Changhua Christian Hospital, Changhua, Taiwan. Because of the growing importance of antibiotic resistant strains of A. baumannii, this study firstly established the native clinical epidemiological database of A. baumannii strains in the central Taiwan area, secondarily analyzed the relationship between genotype (bla Tem—1, and IntI1 gene) and the antibiotic resistance phenotype, and studied the horizontal gene transfer of the bla Tem—1. A cross-sectional, prospective study was conducted at Changhua Christian Hospital during April 1, 2001, and March 31, 2002. A total of 401 clinical A. baumannii strains were collected. The PCR method was used to detect the target resistant genes (bla Tem-1 gene , IntI1 gene). We divided the 401 clinical strains into the 3 clusters and 32 subgroups according to the antibiotics resistant patterns by the finite mixture method. 31.2 % (10/32) A. baumannii possessed the bla Tem-1 gene, while 81.3% (26/32) possessed the IntI1 genes. The DNA sequence of bla tem gene was identical (1044/1044 bp) between the E. coli (AF427133) and the A. baumannii CH 7. According to the SXT susceptibility tests and PCR analysis of the Changhua Christian Hospital, 81.3% (26/32) of clinical strains carried the IntI1 gene, and 84.6%( 22/26) IntI1 positive strains were resistant to SXT. 80.8% (21/26) in IntI1 positive strains were resistant to gentamicin and 16.7%(1/6) in IntI1 negative strains were resistant to gentamicin. The IntI1 gene could result in the SXT and gentamicin resistance. Furthermore, CAZ susceptibility tests and PCR analysis showed that 31.2% (10/32) of clinical strains carried the bla Tem-1 gene, and 100%( 10/10) bla Tem-1 positive strains were CAZ resistant. We concluded that the IntI1 genes could relate to the SXT resistance, and the bla Tem—1 gene could relate to the CAZ resistance. The horizontal gene transfer of the bla Tem—1 gene needed further experiments