Open AccessAchromobacter xylosoxidans Cellular Pathology Is Correlated with Activation of a Type III Secretion System
Author(s) -
Adam M. Pickrum,
Orlando DeLeon,
Aaron T. Dirck,
Maxx H. Tessmer,
Molly O. Riegert,
Julie Biller,
Nathan A. Ledeboer,
John R. Kirby,
Dara W. Frank
Publication year - 2020
Publication title -
infection and immunity
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.508
H-Index - 220
eISSN - 1070-6313
pISSN - 0019-9567
DOI - 10.1128/iai.00136-20
Subject(s) - achromobacter xylosoxidans , biology , cystic fibrosis , secretion , microbiology and biotechnology , achromobacter , bacteria , genetics , biochemistry , pseudomonas
Achromobacter xylosoxidans is increasingly recognized as a colonizer of cystic fibrosis (CF) patients, but the role that A. xylosoxidans plays in pathology remains unknown. This knowledge gap is largely due to the lack of model systems available to study the toxic potential of this bacterium. Recently, a phospholipase A 2 (PLA 2 ) encoded by a majority of A. xylosoxidans genomes, termed AxoU, was identified. Here, we show that AxoU is a type III secretion system (T3SS) substrate that induces cytotoxicity to mammalian cells. A tissue culture model was developed showing that a subset of A. xylosoxidans isolates from CF patients induce cytotoxicity in macrophages, suggestive of a pathogenic or inflammatory role in the CF lung. In a toxic strain, cytotoxicity is correlated with transcriptional activation of axoU and T3SS genes, demonstrating that this model can be used as a tool to identify and track expression of virulence determinants produced by this poorly understood bacterium.