東華大學圖書館 |

Language: English

Help

回圖書館首頁

手機版館藏查詢

Back

Switch To: Labeled | MARC Mode | ISBD

Enterococcus faecalis biofilms: Ana...

Tendolkar, Preeti Mangesh.

Linked to FindBook

Google Book

Amazon

博客來

Enterococcus faecalis biofilms: Analysis of the roles of enterococcal surface protein, ESP, and a newly identified genetic locus.

Record Type:	Electronic resources : Monograph/item
Title/Author:	Enterococcus faecalis biofilms: Analysis of the roles of enterococcal surface protein, ESP, and a newly identified genetic locus./
Author:	Tendolkar, Preeti Mangesh.
Description:	173 p.
Notes:	Source: Dissertation Abstracts International, Volume: 66-06, Section: B, page: 3085.
Contained By:	Dissertation Abstracts International66-06B.
Subject:	Health Sciences, Pharmacy. -
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3177892
ISBN:	0542175215

Enterococcus faecalis biofilms: Analysis of the roles of enterococcal surface protein, ESP, and a newly identified genetic locus.
Tendolkar, Preeti Mangesh.

Enterococcus faecalis biofilms: Analysis of the roles of enterococcal surface protein, ESP, and a newly identified genetic locus. - 173 p.

Source: Dissertation Abstracts International, Volume: 66-06, Section: B, page: 3085.

Thesis (Ph.D.)--The University of Oklahoma Health Sciences Center, 2005.

Biofilms are bacterial communities attached to a surface, and encased in an extracellular polymeric matrix. Enterococci have emerged as one of the leading causes of nosocomial infections, and are frequently associated with biofilms isolated from various indwelling medical devices. Enterococcal surface protein, Esp, has been found to contribute significantly to biofilm formation in E. faecalis. However, certain strains have been shown to form biofilms independent of Esp. The first aim of this study was to precisely define the role Esp plays in E. faecalis biofilm formation. Esp was expressed at the cell surface of natively Esp-deficient strains. Isogenic Esp-positive and Esp-deficient strains were then compared for their biofilm forming abilities. The results show that Esp expression leads to a significant enhancement in biofilm formation, and this process is regulated in a glucose-dependent manner. Since mature Esp consists of multiple domains including a nonrepeat N-terminal domain, a central domain consisting of series of tandem repeats followed by a non-repeat C-terminal domain, the second aim was to localize the domain of Esp critical to biofilm enhancement. In-frame deletion mutants expressing truncated forms of Esp in an isogenic background were assessed for their biofilm forming abilities. We find that the strain expressing Esp lacking the N-terminal domain, formed significantly less biofilms than the strain expressing wild type Esp. Furthermore, an E. faecalis strain expressing the N-terminal domain of Esp alone, fused to a heterologous protein anchor formed biofilms that were quantitatively similar to those formed by a strain expressing full-length Esp. These results imply that the N-terminal domain of Esp is sufficient for Esp-mediated biofilm enhancement in E. faecalis. The third aim was to identify factors other than Esp that may be involved in the process of enterococcal biofilm development. A library of transposon insertion mutants was generated in a high-biofilm forming E. faecalis strain, E99, and screened for mutants with a reduced ability to form biofilms. Using this strategy, we have identified a novel locus encoding surface proteins, which appears to contribute to the high-biofilm phenotype. Moreover, this locus is apparently carried on a mobile genetic element that mediates high-frequency conjugal transfer.

ISBN: 0542175215Subjects--Topical Terms:

1017737
Health Sciences, Pharmacy.

Enterococcus faecalis biofilms: Analysis of the roles of enterococcal surface protein, ESP, and a newly identified genetic locus.
LDR:03333nmm 2200277 4500 001 1816103
005 20060717151151.5
008 130610s2005 eng d
020 $a 0542175215
035 $a (UnM)AAI3177892
035 $a AAI3177892
040 $a UnM $c UnM
100 1 $a Tendolkar, Preeti Mangesh. $3 1905498
245 1 0 $a Enterococcus faecalis biofilms: Analysis of the roles of enterococcal surface protein, ESP, and a newly identified genetic locus.
300 $a 173 p.
500 $a Source: Dissertation Abstracts International, Volume: 66-06, Section: B, page: 3085.
500 $a Chair: Nathan Shankar.
502 $a Thesis (Ph.D.)--The University of Oklahoma Health Sciences Center, 2005.
520 $a Biofilms are bacterial communities attached to a surface, and encased in an extracellular polymeric matrix. Enterococci have emerged as one of the leading causes of nosocomial infections, and are frequently associated with biofilms isolated from various indwelling medical devices. Enterococcal surface protein, Esp, has been found to contribute significantly to biofilm formation in E. faecalis. However, certain strains have been shown to form biofilms independent of Esp. The first aim of this study was to precisely define the role Esp plays in E. faecalis biofilm formation. Esp was expressed at the cell surface of natively Esp-deficient strains. Isogenic Esp-positive and Esp-deficient strains were then compared for their biofilm forming abilities. The results show that Esp expression leads to a significant enhancement in biofilm formation, and this process is regulated in a glucose-dependent manner. Since mature Esp consists of multiple domains including a nonrepeat N-terminal domain, a central domain consisting of series of tandem repeats followed by a non-repeat C-terminal domain, the second aim was to localize the domain of Esp critical to biofilm enhancement. In-frame deletion mutants expressing truncated forms of Esp in an isogenic background were assessed for their biofilm forming abilities. We find that the strain expressing Esp lacking the N-terminal domain, formed significantly less biofilms than the strain expressing wild type Esp. Furthermore, an E. faecalis strain expressing the N-terminal domain of Esp alone, fused to a heterologous protein anchor formed biofilms that were quantitatively similar to those formed by a strain expressing full-length Esp. These results imply that the N-terminal domain of Esp is sufficient for Esp-mediated biofilm enhancement in E. faecalis. The third aim was to identify factors other than Esp that may be involved in the process of enterococcal biofilm development. A library of transposon insertion mutants was generated in a high-biofilm forming E. faecalis strain, E99, and screened for mutants with a reduced ability to form biofilms. Using this strategy, we have identified a novel locus encoding surface proteins, which appears to contribute to the high-biofilm phenotype. Moreover, this locus is apparently carried on a mobile genetic element that mediates high-frequency conjugal transfer.
590 $a School code: 0361.
650 4 $a Health Sciences, Pharmacy. $3 1017737
650 4 $a Biology, Microbiology. $3 1017734
690 $a 0572
690 $a 0410
710 2 0 $a The University of Oklahoma Health Sciences Center. $3 1023966
773 0 $t Dissertation Abstracts International $g 66-06B.
790 1 0 $a Shankar, Nathan, $e advisor
790 $a 0361
791 $a Ph.D.
792 $a 2005
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3177892