Journal article
Identification and Characterization of an RTX Toxin in the Emerging Pathogen Kingella kingae
Journal of bacteriology, Vol.189(2), pp.430-436
01/01/2007
DOI: 10.1128/JB.01319-06
PMCID: PMC1797395
PMID: 17098895
Abstract
Kingella kingae
is an emerging bacterial pathogen that is increasingly recognized as the causative agent of a variety of pediatric diseases, including septic arthritis and osteomyelitis. The pathogenesis of
K. kingae
disease is believed to begin with colonization of the upper respiratory tract. In the present study, we examined interactions between
K. kingae
and cultured respiratory epithelial cells and observed potent cytotoxicity, detected by both microscopy and lactic acid dehydrogenase (LDH) release assays. Experiments with synovial and macrophage cell lines revealed cytotoxicity for these cell types as well. Using mariner mutagenesis and a screen for loss of cytotoxicity, a genetic locus encoding an RTX toxin system was identified. Disruption of the
K. kingae
RTX locus resulted in a loss of cytotoxicity for respiratory epithelial, synovial, and macrophage cell lines. DNA sequence analysis demonstrated that the RTX locus is flanked by insertion elements and has a reduced G+C content compared to that of the whole genome. Two relatively less invasive
Kingella
species,
K. oralis
and
K. denitrificans
, were found to be noncytotoxic and to lack the RTX region, as determined by LDH release assays and Southern blotting. We concluded that
K. kingae
expresses an RTX toxin that has wide cellular specificity and was likely acquired horizontally. The possible roles for this toxin in the pathogenesis of
K. kingae
disease include breaching of the epithelial barrier and destruction of target tissues, such as synovium (joint lining).
Details
- Title: Subtitle
- Identification and Characterization of an RTX Toxin in the Emerging Pathogen Kingella kingae
- Creators
- Thomas E. Kehl-Fie - MallinckrodtJoseph W. St. Geme - Edward Mallinckrodt Department of Pediatrics and Department of Molecular Microbiology, Washington University School of Medicine, 660 S. Euclid Ave., St. Louis, Missouri 63110, Departments of Pediatrics and Molecular Genetics and Microbiology, Duke University Medical Center, Children's Health Center, Durham, North Carolina 27710
- Resource Type
- Journal article
- Publication Details
- Journal of bacteriology, Vol.189(2), pp.430-436
- Publisher
- American Society for Microbiology
- DOI
- 10.1128/JB.01319-06
- PMID
- 17098895
- PMCID
- PMC1797395
- ISSN
- 0021-9193
- eISSN
- 1098-5530
- Language
- English
- Date published
- 01/01/2007
- Academic Unit
- Microbiology and Immunology
- Record Identifier
- 9984618510302771
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