In:
Applied and Environmental Microbiology, American Society for Microbiology, Vol. 81, No. 4 ( 2015-02-15), p. 1274-1285
Abstract:
Pseudomonas aeruginosa is an opportunistic human pathogen that is able to sense and adapt to numerous environmental stimuli by the use of transcriptional regulators, including two-component regulatory systems. In this study, we demonstrate that the sensor kinase PA4398 is involved in the regulation of swarming motility and biofilm formation in P. aeruginosa PA14. A PA4398 − mutant strain was considerably impaired in swarming motility, while biofilm formation was increased by approximately 2-fold. The PA4398 − mutant showed no changes in growth rate, rhamnolipid synthesis, or the production of the Pel exopolysaccharide but exhibited levels of the intracellular second messenger cyclic dimeric GMP (c-di-GMP) 50% higher than those in wild-type cells. The role of PA4398 in gene regulation was investigated by comparing the PA4398 − mutant to the wild-type strain by using microarray analysis, which demonstrated that 64 genes were up- or downregulated more than 1.5-fold ( P 〈 0.05) under swarming conditions. In addition, more-sensitive real-time PCR studies were performed on genes known to be involved in c-di-GMP metabolism. Among the dysregulated genes were several involved in the synthesis and degradation of c-di-GMP or in the biosynthesis, transport, or function of the iron-scavenging siderophores pyoverdine and pyochelin, in agreement with the swarming phenotype observed. By analyzing additional mutants of selected pyoverdine- and pyochelin-related genes, we were able to show that not only pvdQ but also pvdR , fptA , pchA , pchD , and pchH are essential for the normal swarming behavior of P. aeruginosa PA14 and may also contribute to the swarming-deficient phenotype of the PA4398 − mutant in addition to elevated c-di-GMP levels.
Type of Medium:
Online Resource
ISSN:
0099-2240
,
1098-5336
DOI:
10.1128/AEM.02832-14
Language:
English
Publisher:
American Society for Microbiology
Publication Date:
2015
detail.hit.zdb_id:
223011-2
detail.hit.zdb_id:
1478346-0
SSG:
12
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