<em>Acinetobacter baumannii</em> is the main drug resistant bacteria in clinic at present, and its drug resistance is still rising rapidly. Integrons play an important role in bacterial acquisition of exog...<em>Acinetobacter baumannii</em> is the main drug resistant bacteria in clinic at present, and its drug resistance is still rising rapidly. Integrons play an important role in bacterial acquisition of exogenous drug resistance genes. This study investigated <em>A. baumannii</em> colonization in oropharynx and the integron gene carrying, and the expressions of integrase gene were determined when exposed to the different concentrations of antibiotics. 64 hospitalized patients were collected during January 2019 to June in respiratory department of our hospital (the hospitalized time more than 14 days) in our experiment. All throat swab collections were used for DNA extraction, and <em>A. baumannii</em> identification and integron gene detection were done by PCR assay. <em>A. baumannii</em> strains isolated from the oropharynx were identified by MALD-TOF-MS technology and the drug resistance was also analyzed. When expose to a series of ceftazidime and imipenem (10 μg/mL, 5 μg/mL, 1 μg/mL, 0.1 μg/mL, 0.01 μg/mL), the expressions of integron gene in the strains originated from oropharynx were determined by qRT-PCR assay. The results of the PCR showed that 60 patients had detected the <em>A. baumannii </em><em>Ab-ITS</em> gene and rA gene in throat swabs, wherein 43 patients with symptoms of infection and 17 without symptoms of infection. There was no significant difference in <em>Ab-ITS</em> gene and rA gene detection rates in the symptoms of infection and no symptoms of infection (P > 0.05). In total 60 cases of samples, 29 cases had detected the <em>IntI </em>genes. 6 strains of <em>A. baumannii</em> isolated from the throat swabs of hospitalized patients were multi-drug resistant bacteria with <em>IntI</em> gene and variable region genes. Gene sequencing analysis revealed that the variable region gene cassettes were aacA4-catB8-aadA1-qacEdelta1. When exposed to the concentration of 1 μg/mL and 5 μg/mL ceftazidime, the mRNA expression of <em>IntI</em> had significantly increase compared to the negative contro展开更多
基金supported from the National Key Research and Development Program(2021YFF0502300)the National Natural Science Foundation of China(42325603,42022046,42227803,and 41890850)+1 种基金the Guangdong Natural Resources Foundation(GDNRC[2022]45)the PI Project of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)(GML20190609 and GML2022009)。
文摘<em>Acinetobacter baumannii</em> is the main drug resistant bacteria in clinic at present, and its drug resistance is still rising rapidly. Integrons play an important role in bacterial acquisition of exogenous drug resistance genes. This study investigated <em>A. baumannii</em> colonization in oropharynx and the integron gene carrying, and the expressions of integrase gene were determined when exposed to the different concentrations of antibiotics. 64 hospitalized patients were collected during January 2019 to June in respiratory department of our hospital (the hospitalized time more than 14 days) in our experiment. All throat swab collections were used for DNA extraction, and <em>A. baumannii</em> identification and integron gene detection were done by PCR assay. <em>A. baumannii</em> strains isolated from the oropharynx were identified by MALD-TOF-MS technology and the drug resistance was also analyzed. When expose to a series of ceftazidime and imipenem (10 μg/mL, 5 μg/mL, 1 μg/mL, 0.1 μg/mL, 0.01 μg/mL), the expressions of integron gene in the strains originated from oropharynx were determined by qRT-PCR assay. The results of the PCR showed that 60 patients had detected the <em>A. baumannii </em><em>Ab-ITS</em> gene and rA gene in throat swabs, wherein 43 patients with symptoms of infection and 17 without symptoms of infection. There was no significant difference in <em>Ab-ITS</em> gene and rA gene detection rates in the symptoms of infection and no symptoms of infection (P > 0.05). In total 60 cases of samples, 29 cases had detected the <em>IntI </em>genes. 6 strains of <em>A. baumannii</em> isolated from the throat swabs of hospitalized patients were multi-drug resistant bacteria with <em>IntI</em> gene and variable region genes. Gene sequencing analysis revealed that the variable region gene cassettes were aacA4-catB8-aadA1-qacEdelta1. When exposed to the concentration of 1 μg/mL and 5 μg/mL ceftazidime, the mRNA expression of <em>IntI</em> had significantly increase compared to the negative contro
