Infection biologists and proteomics researchers have now identified all the proteins involved in Salmonella metabolic paths during an infection. Dirk Bumann of Hannover Medical School led a team including Daniel Becker, Claudia Rollenhagen, Matthias Ballmaier and Thomas Meyer of the Max Planck Institute for Infection Biology. They isolated Salmonella from infected mice. Proteomics researchers Matthias Selbach and Matthias Mann from the Max Planck Institute of Biochemistry then turned to highly-sensitive mass spectrometry to look at the protein mixture ?and discovered hundreds of different Salmonella metabolic path proteins. The scientists compared them with special protein databanks and identified possible points of attack for antibiotics.
Bumann and his team then examined what role these proteins play in a Salmonella infection. The scientists turned off genes responsible for the proteins to see how it affected the disease's progress. "Knocking out" the gene was equivalent to blocking its corresponding metabolic path, thereby simulating the effect of antibiotics. The analysis demonstrated the following: in the two possible types of salmonella-related illness (diarrhoea and typhoid), the bacteria is surprisingly unaffected by the blockade of several central metabolic pathways. The reason for this is redundant enzymes, as well as the host offering a wide range of nutrients, which means Salmonella does not depend on its own biosynthetic abiliti