Title |
Zur-regulated lipoprotein A contributes to the fitness of Acinetobacter baumannii |
Author |
Eun Kyung Lee1, Chul Hee Choi2, and Man Hwan Oh1* |
Address |
1Department of Nanobiomedical Science, Dankook University, Cheonan 31116, Republic of Korea, 2Department of Microbiology and Medical Sciences, Chungnam National University, School of Medicine, Daejeon 34134, Republic of Korea |
Bibliography |
Journal of Microbiology, 58(1),67-77, 2020,
|
DOI |
10.1007/s12275-020-9531-7
|
Key Words |
Acinetobacter baumannii, Zur, virulence, chaperone-
usher pili assembly system, two-component system |
Abstract |
Acinetobacter baumannii is a notorious nosocomial pathogen
that commonly infects severely ill patients. Zinc (Zn) is
essential to survive and adapt to different environment and
host niches in A. baumannii. Of the Zinc uptake regulator
(Zur)-regulated genes in A. baumannii, the A1S_3412 gene
encoding a Zur-regulated lipoprotein A (ZrlA) is critical for
cell envelope integrity and overcoming antibiotic exposure.
This study investigated whether ZrlA contributes to the fitness
of A. baumannii in vitro and in vivo using the wildtype
A. baumannii ATCC 17978, ΔzrlA mutant, and zrlAcomplemented
strains. The ΔzrlA mutant showed reduced
biofilm formation, surface motility, and adherence to and
invasion of epithelial cells compared to the wild-type strain.
In a mouse pneumonia model, the ΔzrlA mutant showed significantly
lower bacterial numbers in the blood than the wildtype
strain. These virulence traits were restored in the zrlAcomplemented
strain. Under static conditions, the expression
of csuCDE, which are involved in the chaperone-usher
pili assembly system, was significantly lower in the ΔzrlA
mutant than in the wild-type strain. Moreover, the expression
of the bfmR/S genes, which regulate the CsuA/BABCDE system,
was significantly lower in the ΔzrlA mutant under static
conditions than in the wild-type strain. Our results indicate
that the zrlA gene plays a role in the fitness of A. baumannii
by regulating the BfmR/S two-component system and subsequently
the CsuA/BABCDE chaperone-usher pili assembly
system, suggesting it as a potential target for anti-virulence
strategies against A. baumannii. |