Title |
Identification of essential genes of Pseudomonas aeruginosa for its growth in airway mucus |
Author |
Mohammed Abd Alrahman1 and Sang Sun Yoon2* |
Address |
1Department of Microbiology and Immunology, Brain Korea 21 PLUS Project for Medical Science Yonsei University College of Medicine, Seoul 03722, Republic of Korea, 2Institute for Immunology and Immunological Diseases, Yonsei University College of Medicine, Seoul 03722, Republic of Korea |
Bibliography |
Journal of Microbiology, 55(1),68-74, 2017,
|
DOI |
10.1007/s12275-017-6515-3
|
Key Words |
Pseudomonas aeruginosa, airway infection, mucin,
type II secretion system, protease |
Abstract |
Pseudomonas aeruginosa has been identified as an important
causative agent of airway infection, mainly in cystic fibrosis.
This disease is characterized by defective mucociliary clearance
induced in part by mucus hyper-production. Mucin is
a major component of airway mucus and is heavily O-glycosylated,
with a protein backbone. Airway infection is known
to be established with bacterial adhesion to mucin. However,
the genes involved in mucin degradation or utilization remain
elusive. In this study, we sought to provide a genetic basis of
P. aeruginosa airway growth by identifying those genes. First,
using RNASeq analyses, we compared genome-wide expression
profiles of PAO1, a prototype P. aeruginosa laboratory
strain, grown in M9-mucin (M9M) and M9-glucose (M9G)
media. Additionally, a PAO1 transposon (Tn) insertion mutants
library was screened for mutants defective in growth
in M9M medium. One mutant with a Tn insertion in the
xcpU gene (PA3100) was determined to exhibit faulty growth
in M9M medium. This gene contributes to the type II secretion
system, suggesting that P. aeruginosa uses this secretion
system to produce a number of proteins to break down and
assimilate the mucin molecule. Furthermore, we screened
the PAO1 genome for genes with protease activity. Of 13 mutants,
one with mutation in PA3247 gene exhibited defective
growth in M9M, suggesting that the PA3247-encoded protease
plays a role in mucin utilization. Further mechanistic
dissection of this particular process will reveal new drug targets,
the inhibition of which could control recalcitrant P. aeruginosa
infections. |