Molecular Biology and Genetics

Microbial Biotechnology

Electronic Journal of Biotechnology ISSN: 0717-3458 Vol. 10 No. 4, Issue of October 15, 2007
© 2007 by Pontificia Universidad Católica de Valparaíso -- Chile Received November 13, 2006 / Accepted July 9, 2007
DOI: 10.2225/vol10-issue4-fulltext-14

Phage-resistance of Salmonella enterica serovar Enteritidis and pathogenesis in Caenorhabditis elegans is mediated by the lipopolysaccharide

Javier Santander
Center for Infectious Diseases and Vaccinology
Biodesign Institute
Arizona State University
1001 South McAllister Av. Tempe
AZ 85287-5401, USA
Tel: 1 480 727 0465

James Robeson*
Laboratorio de Bacteriología
Instituto de Biología
Pontificia Universidad Católica de Valparaíso
Av. Brasil 2950, Valparaíso, Chile
Tel: 56 32 227 3118

*Corresponding author

Financial support: Vice-Rectoria de Investigación y Estudios Avanzados, Pontificia Universidad Católica de Valparaíso.

Keywords: animal model, bacteriophage prophylaxis, Caenorhabditis elegans, phage resistance, Salmonella.


LPS: lipopolysaccharide
O-PS: O-polysaccharide
Pla: virulence plasmid
SDS-PAGE: sodium dodecyl sulfate-polyacrylamide gel electrophoresis

Full Text

Phage therapy has been used in the past as an alternative therapy against bacterial pathogens. However, phage-resistant bacterial strains can emerge. Some studies show that these phage-resistant strains are avirulent. In this study, we report that phage-resistant strains of Salmonella enterica serovar Enteritidis (hereafter S. Enteritidis) were avirulent in the Caenorhabditis elegans animal model. We isolated phage-resistant strains of S. Enteritidis ATCC 13076 by using three lytic phages (f2αSE, f3αSE and f18αSE). In these mutants, we explored different virulence factors like lipopolysaccharide (LPS), virulence plasmid (Pla), motility and type I fimbriae, all of which may have effects on virulence and could furthermore be related to phage resistance. The phage-resistant strains of S. Enteritidis showed loss of O-Polysaccharide (O-PS) and auto-agglutination, present a rough phenotype and consequently they are avirulent in the C. elegans animal model. We speculate that the O-PS is necessary for phage attachment to the S. Enteritidis cell surface.

Supported by UNESCO / MIRCEN network