一株含新的mucA突变基因的黏液型铜绿假单胞菌的生物学特性

The biological characteristics of a mucoid Pseudomonas aeruginosa strain with a newly discovered mutation of mucA gene

目的 研究黏液型铜绿假单胞菌PA17中的mucA基因序列及其生物膜形成、生长速度和耐药性 ,并与铜绿假单胞菌标准菌株PAOI进行比较。方法 采用聚合酶链反应 (PCR)方法分别扩增PA17与非黏液型铜绿假单胞菌标准菌株PAOI的mucA基因 ,全自动荧光测序仪测序。同时用改良的平板培养法分别建立PA17和PAOI的生物膜模型 ,于 8h、2 4h、3d、6d用扫描电镜检测生物膜形成情况。稀释平板计数法比较PA17和PAOI的生长曲线 ,国际标准琼脂平皿二倍稀释法检测常用抗生素对上述两菌株的体外抗菌活性。结果 PA17mucA基因第 16 6 333位核苷酸缺失 ;其生物膜形成速度及生长速度明显慢于PAOI;PA17与PAOI对常用抗生素的耐药性一致。结论 发现一株含新的mucA突变基因的黏液型铜绿假单胞菌 ,其生物学特性不同于以往报道的黏液型铜绿假单胞菌 。

Objective To compare the mucA gene sequence,biofilm formation,growth rate and antibiotic resistance of a mucoid Pseudomonas aeruginosa strain ‘PA17’ with those of the nonmucoid strain PAOI Methods The mucA genes of PA17 and PAOI were amplified and the PCR products were sequenced Biofilm was established and detected with scanning electron microscope 8 h, 24 h, 3 d and 6 d later Clones counting method was used to compare the growth curves of PA17 and PAOI International standard plate dilution method was used to detect the susceptibility of common antibiotics for PA17 and PAOI in vitro Results There was a 166 333 deletion mutation in mucA gene of PA17 The biofilm formation rate and growth rate of PA17 were noticeably lower than those of PAOI The antibiotic resistance profile of PA17 was identical to that of PAOI Conclusion A mucoid Pseodomonas aeruginosa with a new type of mutation of mucA gene is discovered.The biologic characteristics of this strain are different from those of the mucoid Pseodomonas aeruginosa strain reported previously, which may be related with the newly discovered mutation of mucA gene