Background Acinetobacter baumanii （A. baumanii ） remains an important microbial pathogen resulting in nosocomialacquired infections with significant morbidity and mortality. The mechanism by which nosocomial bacteri...Background Acinetobacter baumanii （A. baumanii ） remains an important microbial pathogen resulting in nosocomialacquired infections with significant morbidity and mortality. The mechanism by which nosocomial bacteria, like A. baumanii, attain multidrug resistance to antibiotics is of considerable interest. The aim in this study was to investigate the spread status of antibiotic resistance genes, such as multiple 13-1actamase genes and aminoglycoside-modifying enzyme genes, from A. baumanii strains isolated from patients with lower respiratory tract infections （LRTIs）. Methods Two thousand six hundred and ninety-eight sputum or the bronchoalveolar lavage samples from inpatients with LRTIs were collected in 21 hospitals in the mainland of China from November 2007 to February 2009. All samples were routinely inoculated. The isolated bacterial strains and their susceptibility were analyzed via VITEK-2 expert system. Several kinds of antibiotic resistant genes were further differentiated via polymerase chain reaction and sequencing methods. Results Totally, 39 A. baumanii strains were isolated from 2698 sputum or bronchoalveolar lavage samples. There was not only a high resistant rate of the isolated A. baumanfi strains to ampicillin and first- and second-generation cephalosporins （94.87%, 100% and 97.44%, respectively）, but also to the third-generation cephalosporins （ceftriaxone at 92.31%, ceftazidine at 51.28%） and imipenem （43.59%） as well. The lowest antibiotic resistance rate of 20.51% was found to amikacin. The OXA-23 gene was identified in 17 strains of A. baumanii, and the AmpC gene in 23 strains. The TEM-1 gene was carried in 15 strains. PER-1 and SHV-2 genes were detected in two different strains. Aminoglycoside-modifying enzyme gene aac-3-1a was found in 23 strains, and the aac-6＂lb gene in 19 strains, aac-3-1a and aac-6＂lb genes hibernated in three A. baumanfi strains that showed no drug-resistant phenotype. Conclusions A. baumanii can carry multiple drug-resistant genes at the sam展开更多
文摘Background Acinetobacter baumanii （A. baumanii ） remains an important microbial pathogen resulting in nosocomialacquired infections with significant morbidity and mortality. The mechanism by which nosocomial bacteria, like A. baumanii, attain multidrug resistance to antibiotics is of considerable interest. The aim in this study was to investigate the spread status of antibiotic resistance genes, such as multiple 13-1actamase genes and aminoglycoside-modifying enzyme genes, from A. baumanii strains isolated from patients with lower respiratory tract infections （LRTIs）. Methods Two thousand six hundred and ninety-eight sputum or the bronchoalveolar lavage samples from inpatients with LRTIs were collected in 21 hospitals in the mainland of China from November 2007 to February 2009. All samples were routinely inoculated. The isolated bacterial strains and their susceptibility were analyzed via VITEK-2 expert system. Several kinds of antibiotic resistant genes were further differentiated via polymerase chain reaction and sequencing methods. Results Totally, 39 A. baumanii strains were isolated from 2698 sputum or bronchoalveolar lavage samples. There was not only a high resistant rate of the isolated A. baumanfi strains to ampicillin and first- and second-generation cephalosporins （94.87%, 100% and 97.44%, respectively）, but also to the third-generation cephalosporins （ceftriaxone at 92.31%, ceftazidine at 51.28%） and imipenem （43.59%） as well. The lowest antibiotic resistance rate of 20.51% was found to amikacin. The OXA-23 gene was identified in 17 strains of A. baumanii, and the AmpC gene in 23 strains. The TEM-1 gene was carried in 15 strains. PER-1 and SHV-2 genes were detected in two different strains. Aminoglycoside-modifying enzyme gene aac-3-1a was found in 23 strains, and the aac-6＂lb gene in 19 strains, aac-3-1a and aac-6＂lb genes hibernated in three A. baumanfi strains that showed no drug-resistant phenotype. Conclusions A. baumanii can carry multiple drug-resistant genes at the sam
