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Identification of the genetic determinants of Salmonella enterica serotype Typhimurium that may regulate the expression of the type 1 fimbriae in response to solid agar and static broth culture conditions.
- Source :
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BMC microbiology [BMC Microbiol] 2008 Jul 25; Vol. 8, pp. 126. Date of Electronic Publication: 2008 Jul 25. - Publication Year :
- 2008
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Abstract
- Background: Type 1 fimbriae are the most commonly found fimbrial appendages on the outer membrane of Salmonella enterica serotype Typhimurium. Previous investigations indicate that static broth culture favours S. Typhimurium to produce type 1 fimbriae, while non-fimbriate bacteria are obtained by growth on solid agar media. The phenotypic expression of type 1 fimbriae in S. Typhimurium is the result of the interaction and cooperation of several genes in the fim gene cluster. Other gene products that may also participate in the regulation of type 1 fimbrial expression remain uncharacterized.<br />Results: In the present study, transposon insertion mutagenesis was performed on S. Typhimurium to generate a library to screen for those mutants that would exhibit different type 1 fimbrial phenotypes than the parental strain. Eight-two mutants were obtained from 7,239 clones screened using the yeast agglutination test. Forty-four mutants produced type 1 fimbriae on both solid agar and static broth media, while none of the other 38 mutants formed type 1 fimbriae in either culture condition. The flanking sequences of the transposons from 54 mutants were cloned and sequenced. These mutants can be classified according to the functions or putative functions of the open reading frames disrupted by the transposon. Our current results indicate that the genetic determinants such as those involved in the fimbrial biogenesis and regulation, global regulators, transporter proteins, prophage-derived proteins, and enzymes of different functions, to name a few, may play a role in the regulation of type 1 fimbrial expression in response to solid agar and static broth culture conditions. A complementation test revealed that transforming a recombinant plasmid possessing the coding sequence of a NAD(P)H-flavin reductase gene ubiB restored an ubiB mutant to exhibit the type 1 fimbrial phenotype as its parental strain.<br />Conclusion: Genetic determinants other than the fim genes may involve in the regulation of type 1 fimbrial expression in S. Typhimurium. How each gene product may influence type 1 fimbrial expression is an interesting research topic which warrants further investigation.
- Subjects :
- Antigens, Bacterial genetics
Bacterial Proteins metabolism
DNA Transposable Elements
FMN Reductase genetics
FMN Reductase metabolism
Fimbriae Proteins genetics
Fimbriae, Bacterial metabolism
Fimbriae, Bacterial ultrastructure
Gene Library
Genetic Complementation Test
Mutagenesis, Insertional
Phenotype
Salmonella typhimurium metabolism
Salmonella typhimurium ultrastructure
Transcription, Genetic
Bacterial Proteins genetics
Culture Media chemistry
Fimbriae, Bacterial genetics
Gene Expression
Salmonella typhimurium genetics
Subjects
Details
- Language :
- English
- ISSN :
- 1471-2180
- Volume :
- 8
- Database :
- MEDLINE
- Journal :
- BMC microbiology
- Publication Type :
- Academic Journal
- Accession number :
- 18652702
- Full Text :
- https://doi.org/10.1186/1471-2180-8-126