Title

Presence of Bacterial Virulence Gene Homologues in the dibenzo-p-dioxins degrading bacterium Sphingomonas wittichii

Authors

Amr T. M. Saeb*

Affiliation

Biotechnology Department, Strategic Center for Diabetes Research, College of medicine, King Saud University, Saudi Arabia.

Email

Amr T. M. Saeb, E-mail: saeb.1@osu.edu; Corresponding author

Article Type

Hypothesis

Date

Received May 29, 2016; Revised June 22, 2016; Accepted June 23, 2016; Published July 26, 2016

Sphingomonas wittichii, a close relative of the human pathogen Sphingomonas paucimobilis, is a microorganism of great interest to the bioremediation community for its ability of biodegradation to a large number of toxic polychlorinated dioxins. In the present study we investigated the presence of different virulence factors and genes in S. wittichii. We utilized phylogenetic, comparative genomics and
bioinformatics analysis to investigate the potentiality of S. wittichii as a potential virulent pathogen. The 16SrDNA phylogenetic tree showed that the closest bacterial taxon to S. wittichii is Brucella followed by Helicobacter, Campylobacter, Pseudomonas then Legionella. Despite their close phylogenetic relationship, S. wittichii did not share any virulence factors with Helicobacter or Campylobacter. On the
contrary, in spite of the phylogenetic divergence between S. wittichii and Pseudomonas spp., they shared many major virulence factors, such as, adherence, antiphagocytosis, Iron uptake, proteases and quorum sensing. S. wittichii contains several major virulence factors resembling Pseudomonas sp., Legionella sp., Brucella sp. and Bordetella sp. virulence factors. Similarity of virulence factors did not match
phylogenetic relationships. These findings suggest horizontal gene transfer of virulence factors rather than sharing a common pathogenic ancestor. S. wittichii is a potential virulent bacterium. Another possibility is that reductive evolution process attenuated S. wittichii pathogenic capabilities. Thus plenty of care must be taken when using this bacterium in soil remediation purposes.

Keywords

Sphingomonas wittichii, Virulence factors, Phylogenetics, Comparative genomics, Bioinformatics, Pseudomonas sp.

Citation

Saeb, Bioinformation 12(4): 241-248 (2016)

Edited by

P Kangueane

ISSN

0973-2063

Publisher

Biomedical Informatics

License

This is an Open Access article which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. This is distributed under the terms of the Creative Commons Attribution License.