Date of Award

8-2010

Document Type

Thesis

Degree Name

Master of Science (MS)

Legacy Department

Microbiology

Advisor

CAO, MIN

Committee Member

HUGHES , THOMAS A.

Committee Member

DONG , YUQING

Abstract

ABSTRACT
Listeria monocytogenes is a ubiquitous gram positive food borne pathogen. Ingestion of L.monocytogenes contaminated food can cause serious infections in immune-compromised persons. In addition to planktonic growth, this pathogen can also grow as biofilms under adverse conditions, which has been proved to be more resistant than its planktonic counterpart to various eradications, such as antibiotic treatments. Compared with the extensively studied intracellular replication mechanisms, L.monocytogenes biofilm developmental process is not well understood.
Our research group initiated a systemic study on the molecular mechanisms of L.monocytogenes biofilm formation. A whole genome-scale screening for functional factors involved in L.monocytogenes biofilm development was carried out by means of transposon mutagenesis in combination with microtiter plate assay. 14 mutants with an at least 50% decreased biofilm formation were selected from 10,000 transposon mutants. Transposon locations in these 14 mutants were identified through NEST-PCR and sequencing. The in-frame deletion mutant of two genes, lmo2553 and lmo2554, were generated and showed similar biofilm formation defects as the transposon mutant. The roles of these genes in L.monocytogenes biofilm development will be further pursued in the future.

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Microbiology Commons

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