Relationship between virulence factor and toxin antitoxin system in enterococcus

Toxin-antitoxin system is a regulatory system where two sets of genes encodes the toxin and its corresponding antitoxin. There is no documented study that showed the association between virulence genes and TA system in Enterococcus faecium and Enterococcus faecalis. For this purpose,the prev...

Full description

Saved in:
Bibliographic Details
Main Author: Soheili, Sara
Format: Thesis
Language:English
Published: 2014
Subjects:
Online Access:http://psasir.upm.edu.my/id/eprint/75356/1/FPSK%28M%29%202014%206%20IR.pdf
Tags: Add Tag
No Tags, Be the first to tag this record!
id my-upm-ir.75356
record_format uketd_dc
spelling my-upm-ir.753562019-11-21T08:18:26Z Relationship between virulence factor and toxin antitoxin system in enterococcus 2014-09 Soheili, Sara Toxin-antitoxin system is a regulatory system where two sets of genes encodes the toxin and its corresponding antitoxin. There is no documented study that showed the association between virulence genes and TA system in Enterococcus faecium and Enterococcus faecalis. For this purpose,the prevalence of TA systems in independently isolated clinical isolates of E. faecium and E. faecalis were determined, then the dominant TA systems were identified, different virulence genes in E. faecium and E. faecalisare surveyed and subsequently the level of expression of virulence and TA genes in normal and stress conditions were determined and finally their association with TA genes are defined.Remarkably, sequences for one particular TA pair, mazEF and higBATA systems, were present on plasmid and chromosome of all E. faecium andE. faecalis strains, respectively. Additionally, toxin transcript expression levels were increased when bacteria were grown under stressful conditions. The pilB, fms8, efaAfm and sgrA are the most prevalent virulence genes in E. faecium and E. faecalis. These virulence genes were reported for first time in E. Faecalis, so this study demonstrated the importance of horizontal transformation in E. faecium and E. Faecalis. Peptide nucleic acid assay demonstrated with silencing of mazF by anti-mazF PNA a decrease of expression level of virulence genes were observed. The findings showed association between TA systems and virulence factor. The mazEF TA locion plasmid and higBA TA genes on chromosome of all E. faecium and E. faecalis were dominant. Also, there was decreasing of expression of virulence genes in presence of anti mazF-PNA. Therefore, it is recommended that mazEF TA systems are potent and sensitive targets in of all E. faecium and E.Faecalis. Hence, deactivation of the toxin proteins in the mazEF TA system should be investigated further as an effective antibacterial strategy against this bacterium. Enterococcus - genetics Virulence - physiology Virulence - genetics 2014-09 Thesis http://psasir.upm.edu.my/id/eprint/75356/ http://psasir.upm.edu.my/id/eprint/75356/1/FPSK%28M%29%202014%206%20IR.pdf text en public masters Universiti Putra Malaysia Enterococcus - genetics Virulence - physiology Virulence - genetics
institution Universiti Putra Malaysia
collection PSAS Institutional Repository
language English
topic Enterococcus - genetics
Virulence - physiology
Virulence - genetics
spellingShingle Enterococcus - genetics
Virulence - physiology
Virulence - genetics
Soheili, Sara
Relationship between virulence factor and toxin antitoxin system in enterococcus
description Toxin-antitoxin system is a regulatory system where two sets of genes encodes the toxin and its corresponding antitoxin. There is no documented study that showed the association between virulence genes and TA system in Enterococcus faecium and Enterococcus faecalis. For this purpose,the prevalence of TA systems in independently isolated clinical isolates of E. faecium and E. faecalis were determined, then the dominant TA systems were identified, different virulence genes in E. faecium and E. faecalisare surveyed and subsequently the level of expression of virulence and TA genes in normal and stress conditions were determined and finally their association with TA genes are defined.Remarkably, sequences for one particular TA pair, mazEF and higBATA systems, were present on plasmid and chromosome of all E. faecium andE. faecalis strains, respectively. Additionally, toxin transcript expression levels were increased when bacteria were grown under stressful conditions. The pilB, fms8, efaAfm and sgrA are the most prevalent virulence genes in E. faecium and E. faecalis. These virulence genes were reported for first time in E. Faecalis, so this study demonstrated the importance of horizontal transformation in E. faecium and E. Faecalis. Peptide nucleic acid assay demonstrated with silencing of mazF by anti-mazF PNA a decrease of expression level of virulence genes were observed. The findings showed association between TA systems and virulence factor. The mazEF TA locion plasmid and higBA TA genes on chromosome of all E. faecium and E. faecalis were dominant. Also, there was decreasing of expression of virulence genes in presence of anti mazF-PNA. Therefore, it is recommended that mazEF TA systems are potent and sensitive targets in of all E. faecium and E.Faecalis. Hence, deactivation of the toxin proteins in the mazEF TA system should be investigated further as an effective antibacterial strategy against this bacterium.
format Thesis
qualification_level Master's degree
author Soheili, Sara
author_facet Soheili, Sara
author_sort Soheili, Sara
title Relationship between virulence factor and toxin antitoxin system in enterococcus
title_short Relationship between virulence factor and toxin antitoxin system in enterococcus
title_full Relationship between virulence factor and toxin antitoxin system in enterococcus
title_fullStr Relationship between virulence factor and toxin antitoxin system in enterococcus
title_full_unstemmed Relationship between virulence factor and toxin antitoxin system in enterococcus
title_sort relationship between virulence factor and toxin antitoxin system in enterococcus
granting_institution Universiti Putra Malaysia
publishDate 2014
url http://psasir.upm.edu.my/id/eprint/75356/1/FPSK%28M%29%202014%206%20IR.pdf
_version_ 1747813036864831488