论文部分内容阅读
目的分析铜绿假单胞菌中Ⅰ类整合子可变区的长度对Ⅰ类整合酶基因(intⅠ1)表达水平的影响,以探讨整合酶表达的调控机制。方法将25株临床分离的Ⅰ类整合子阳性铜绿假单胞菌按可变区的长度分为A、B组(A组:1000～2000bp;B组:>2000bp),提取细菌的总RNA并逆转录为cDNA,用实时荧光定量PCR法测定两组细菌intⅠ1mRNA的相对表达量,并比较具有不同长度可变区的细菌中intⅠ1基因的平均表达水平。结果两组细菌中intⅠ1mRNA的相对表达量差异有统计学意义(P<0.05);A组细菌intⅠ1和16SrRNA的Ct值均值及⊿Ct值分别为:17.25、10.34、6.91,B组细菌intⅠ1和16SrRNA的Ct值均值及⊿Ct值分别为:18.91、9.47、9.45,⊿⊿Ct为5.81;A组细菌的intⅠ1mRNA平均表达水平是B组的5.81倍。结论在临床分离的Ⅰ类整合子阳性的铜绿假单胞菌中,短可变区组整合酶表达水平较高,而长可变区组整合酶表达水平较低,提示Ⅰ类整合子中整合酶的表达水平可能受整合子可变区基因盒数目的影响,从而影响整合子继续捕获基因盒的能力。
Objective To analyze the influence of the length of the variable region of class Ⅰ integrons in Pseudomonas aeruginosa on the expression of type Ⅰ integrase gene (intⅠ1) in order to investigate the regulation mechanism of integrase expression. Methods A total of 25 clinical isolates of class Ⅰ integron-positive Pseudomonas aeruginosa were divided into groups A and B according to the length of variable region (group A: 1000-2000bp; group B:> 2000bp) Reverse transcribed into cDNA, and the relative expression of intI1 mRNA in two groups of bacteria was determined by real-time fluorescence quantitative PCR. The average expression level of intI1 gene in bacteria with different length variable regions was compared. Results The relative expression of intⅠ1 mRNA in the two groups of bacteria was significantly different (P <0.05). The average values of Ct values and ⊿Ct values of intⅠ1 and 16SrRNA in group A were 17.25,10.34,6.91, The mean Ct value and ⊿Ct value were 18.91, 9.47 and 9.45, respectively, and the ⊿⊿Ct was 5.81. The average expression level of intⅠ1 mRNA in group A was 5.81 times that of group B. Conclusions In the class Ⅰ integron positive Pseudomonas aeruginosa isolated from clinical isolates, the expression level of short variable region integrase was higher, while that of long variable region group was lower, suggesting that the integron of class Ⅰ integron The level of enzyme expression may be affected by the number of adapter boxes in the integron, thereby affecting the integrin’s ability to continue to capture the gene cassette.