aro mutations in Salmonella enterica cause defects in cell wall and outer membrane integrity.
In this study we characterized aro mutants of Salmonella enterica serovars Enteritidis and Typhimurium, which are frequently used as live oral vaccines. We found that the aroA, aroD, and aroC mutants were sensitive to blood serum, albumen, EDTA, and ovotransferrin, and this defect could be complemented by an appropriate aro gene cloned in a plasmid. Subsequent microarray analysis of gene expression in the aroD mutant in serovar Typhimurium indicated that the reason for this sensitivity might be the upregulation of murA. To confirm this, we artificially overexpressed murA from a multicopy plasmid, and this overexpression caused sensitivity of the strain to albumen and EDTA but not to serum and ovotransferrin. We concluded that attenuation of aro mutants is caused not only by their inability to synthesize aromatic metabolites but also by their defect in cell wall and outer membrane functions associated with decreased resistance to components of innate immune response.
Sebkova
Alena
A
Veterinary Research Institute, Hudcova 70, 621 00 Brno, Czech Republic.
Karasova
Daniela
D
Crhanova
Magdalena
M
Budinska
Eva
E
Rychlik
Ivan
I
D000418:Albumins / Q000494:pharmacology; D019883:Alkyl and Aryl Transferases / Q000235:genetics; D024322:Amino Acids, Aromatic / Q000096:biosynthesis / Q000235:genetics*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002462:Cell Membrane / Q000187:drug effects / Q000235:genetics*; D002473:Cell Wall / Q000187:drug effects / Q000235:genetics*; D003001:Cloning, Molecular; D003165:Complement System Proteins / Q000494:pharmacology; D003207:Conalbumin / Q000494:pharmacology; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D004492:Edetic Acid / Q000494:pharmacology; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D010728:Phosphoenolpyruvate / Q000378:metabolism; D010957:Plasmids / Q000235:genetics; D012477:Salmonella enteritidis / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D012486:Salmonella typhimurium / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D044967:Serum
D000418:Albumins; D024322:Amino Acids, Aromatic; D000900:Anti-Bacterial Agents; D003207:Conalbumin; D010728:Phosphoenolpyruvate; D003165:Complement System Proteins; D004492:Edetic Acid; D019883:Alkyl and Aryl Transferases; C022566:UDP-N-acetylglucosamine 1-carboxyvinyltransferase