This study aimed to investigate the effects of PmrB△Leu172 on polymyxin B resistance in Pseudomonas aeruginosa.Pseudomonas aeruginosa PmrB△Leu172 strain was constructed by homologous recombination technology,and the minimum inhibitory concentration of polymyxin B against wild type and mutant strains were determined by the broth microdilution technique.The effect of PmrB△Leu172 mutation on gene transcription level was determined by RNA sequencing.Reverse transcription quantitative PCR was used to verify the effect of PmrB△Leu172 mutation on the transcription level of PmrB-regulated genes in P.aeruginosa.The results showed that the minimum inhibitory concentration and minimum bactericidal concentration of mutant strain were 4 and 2 times higher than that of wild-type,respectively,and the transcription level of PmrB-regulated genes was also up-regulated.The results suggested that PmrB△Leu172 mutation of P.aeruginosa can enhance the regulation of PmrA-PmrB two-componentsystem,which leads to the resistance of P.aeruginosa to polymyxin B.
关键词
铜绿假单胞菌/pmrB/耐药性/多黏菌素B
Key words
Pseudomonas aeruginosa/pmrB/drug resistance/polymyxin B
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