The effect of siderophore virulence gene entB on the virulence of Carbapenem-resistant Klebsiella pneumoniae
10.3760/cma.j.cn114452-20211029-00668
- VernacularTitle:铁载体毒力基因 entB对碳青霉烯类耐药肺炎克雷伯菌毒力的影响
- Author:
Ruihui HAN
1
;
Min NIU
;
Shumin LIU
;
Jiandie BI
;
Yan DU
Author Information
1. 昆明医科大学第一附属医院医学检验科 云南省检验医学重点实验室 云南省医学检验临床医学研究中心，昆明650032
- Keywords:
Klebsiella pneumoniae;
Carbapenem resistance;
Siderophore;
Virulence gene
- From:
Chinese Journal of Laboratory Medicine
2022;45(6):642-648
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To study the effect of the siderophore virulence gene entB on the virulence of carbapenem-resistant Klebsiella pneumonia (CRKP). Methods:CRKP-27 was selected as the experimental strain from 30 CRKP strains collected from the First Affiliated Hospital of Kunming Medical University. The knockdown strain (Δ entB) and complementing strain (C-Δ entB) were constructed by the clustered regularly interspaced short palindromic repeat-Cas9 technology, and verified by polymerase chain reaction (PCR). In order to initially understand the effect of entB on CRKP colony morphology and virulence phenotype, the colony morphology of CRKP-27, Δ entB, and C-Δ entB strains were observed and string test were tested. Draw the growth curve of the strains and determine the effect of entB on the growth of the CRKP strains. The siderophores production ability of the strains were detected quantitatively using chrome azurol S (CAS) detection solution. Mice model of inflammation was established to observe the survival rate of mice and intuitively understand the effect of entB on CRKP virulence. Results:The PCR results showed that the Δ entB strain and C-Δ entB stranin were constructed successfully. The entB has no significant effect on the colony morphology, capsule and virulence phenotype of CRKP. The growth rate of Δ entB was significantly faster than that of CRKP-27( P=0.008) and C-Δ entB ( P=0.001), which showed that entB weakened the growth ability of CRKP. Compared with CRKP-27( P=0.001) and C-Δ entB( P=0.001), the siderophore production of Δ entB was significantly decreased by 11.739 3% and 11.964 2%, indicating that entB gene increased the capacity of CRKP to produce siderophpres. In animal experiments, compared with CRKP-27( P=0.023) and C-Δ entB( P=0.024), the survival rate of mice in the Δ entB group was significantly increased, indicating that the entB increased the virulence of the CRKP. Conclusion:The siderophore virulence gene entB significantly weakened the growth ability of the strain, but clearly enhanced the siderophore production capacity and virulence of CRKP.
