Construction and characterization of a modA gene mutant strain of Klebsiella pneumoniae
10.12122/j.issn.1673-4254.2024.04.17
- VernacularTitle:肺炎克雷伯菌钼酸盐转运体modA基因缺失株的构建及其生物学特性
- Author:
Hui WANG
1
;
Xiaoyu JIANG
;
Feiyu LI
Author Information
1. 黄石市妇幼保健院(湖北理工学院附属妇幼保健院)检验科,湖北 黄石 435000;湖北医药学院基础医学院,湖北 十堰 442000
- Keywords:
Klebsiella pneumoniae;
ModA protein;
anaerobic growth;
bacterial morphology
- From:
Journal of Southern Medical University
2024;44(4):748-756
- CountryChina
- Language:Chinese
-
Abstract:
Objective To construct a mutant strain of Klebsiella pneumoniae NTUH-K2044 with modA gene deletion and its complementary strain and explore the role of modA gene in modulating anaerobic nitrate respiratory growth and phenotypes of K. pneumoniae. Methods The modA deletion mutant K. pneumoniae strain was constructed by homologous recombination using the suicide vector pKO3-Km. To obtain the complementary strain C-modA, the whole sequence fragment containing the promoter, open reading frame and terminator regions of modA was cloned into pGEM-T-easy and electrically transformed into the modA deletion mutant. The NTUH-K2044 wild-type strain, modA gene deletion mutant and complementary strain were compared by measuring in vitro anaerobic nitrate respiration growth, competitiveness index, biofilm quantification, mucoviscosity assay and morphological measurement using Image J. Results The modA deletion mutant strain ΔmodA and the complementary strain C-modA were successfully constructed. The modA gene knockout strain showed inhibited anaerobic nitrate respiratory growth compared with the wild-type and C-modA strains with significantly weakened competitiveness, reduced capacity of biofilm synthesis during anaerobiosis, and lowered mucoviscosity under anaerobic conditions. The ΔmodA strain showed a spherical morphology in anaerobic conditions as compared with the normal short rod-like morphology of K. pneumoniae, with also distinctly shorter length than the wild-type and C-modA strains. Conclusion The molybdate transport system encoding gene modA is associated with the pathogenic capacity of K. pneumoniae by modulating its anaerobic nitrate respiration, competitiveness, biofilm formation, hypermucoviscous phenotype and morphology.
