ppGpp signaling plays a critical role in virulence of Acinetobacter baumannii

Kyeongmin Kim; Maidul Islam; Hye-Won Jung; Daejin Lim; Kwangsoo Kim; Sung-Gwon Lee; Chungoo Park; Je Chul Lee; Minsang Shin

doi:10.1080/21505594.2021.1961660

ppGpp signaling plays a critical role in virulence of Acinetobacter baumannii

Virulence. 2021 Dec;12(1):2122-2132. doi: 10.1080/21505594.2021.1961660.

Authors

Kyeongmin Kim¹, Maidul Islam¹, Hye-Won Jung¹, Daejin Lim², Kwangsoo Kim², Sung-Gwon Lee³, Chungoo Park³, Je Chul Lee¹, Minsang Shin¹

Affiliations

¹ Department of Microbiology, School of Medicine, Kyungpook National University, Jung-gu, Daegu, South Korea.
² Department of Microbiology, Chonnam National University Medical School, Gwangju South Korea.
³ School of Biological Sciences and Technology, Chonnam National University, Gwangju South Korea.

Abstract

Acinetobacter baumannii, a major nosocomial pathogen, survives in diverse hospital environments, and its multidrug resistance is a major concern. The ppGpp-dependent stringent response mediates the reprogramming of genes with diverse functions in several bacteria. We investigated whether ppGpp is involved in A. baumannii's pathogenesis by examining biofilm formation, surface motility, adhesion, invasion, and mouse infection studies. Transcriptome analysis of early stationary phase cultures revealed 498 differentially-expressed genes (≥ 2-fold change) in a ppGpp-deficient A. baumannii strain; 220 and 278 genes were up and downregulated, respectively. Csu operon expression, important in pilus biosynthesis during early biofilm formation, was significantly reduced in the ppGpp-deficient strain. Our findings suggest that ppGpp signaling influences A. baumannii biofilm formation, surface motility, adherence, and virulence. We showed the association between ppGpp and pathogenicity in A. baumannii for the first time; ppGpp may be a novel antivirulence target in A. baumannii.

Keywords: Acinetobacter baumannii; biofilm; ppGpp; transcriptome; virulence.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Acinetobacter baumannii* / genetics
Acinetobacter baumannii* / pathogenicity
Animals
Biofilms
Fimbriae, Bacterial
Gene Expression Regulation, Bacterial
Guanosine Tetraphosphate / metabolism*
Mice
Operon
Transcriptome
Virulence*

Substances

Guanosine Tetraphosphate

Grants and funding

This work was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF), funded by the Ministry of Education [2016R1D1A1B01008960].