title: Characterization of the pivotal carbon metabolism of Streptococcus suis serotype 2 under ex vivo and chemically defined in vitro conditions by isotopologue profiling.
abstract: Streptococcus suis is a neglected zoonotic pathogen that has to adapt to the nutritional requirements in the different host niches encountered during infection and establishment of invasive diseases. To dissect the central metabolic activity of S. suis under different conditions of nutrient availability, we performed labeling experiments starting from [(13)C]glucose specimens and analyzed the resulting isotopologue patterns in amino acids of S. suis grown under in vitro and ex vivo conditions. In combination with classical growth experiments, we found that S. suis is auxotrophic for Arg, Gln/Glu, His, Leu, and Trp in chemically defined medium. De novo biosynthesis was shown for Ala, Asp, Ser, and Thr at high rates and for Gly, Lys, Phe, Tyr, and Val at moderate or low rates, respectively. Glucose degradation occurred mainly by glycolysis and to a minor extent by the pentose phosphate pathway. Furthermore, the exclusive formation of oxaloacetate by phosphoenolpyruvate (PEP) carboxylation became evident from the patterns in de novo synthesized amino acids. Labeling experiments with S. suis grown ex vivo in blood or cerebrospinal fluid reflected the metabolic adaptation to these host niches with different nutrient availability; however, similar key metabolic activities were identified under these conditions. This points at the robustness of the core metabolic pathways in S. suis during the infection process. The crucial role of PEP carboxylation for growth of S. suis in the host was supported by experiments with a PEP carboxylase-deficient mutant strain in blood and cerebrospinal fluid.
authors.affiliation: From the Institute of Microbiology, University of Veterinary Medicine Hannover, D-30173 Hannover, Germany and joerg.willenborg@tiho-hannover.de.
authors.forename: Jörg
authors.initials: J
authors.lastname: Willenborg
authors.affiliation: the Lehrstuhl für Biochemie, Technische Universität München, D-85747 Garching, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Huber
authors.affiliation: From the Institute of Microbiology, University of Veterinary Medicine Hannover, D-30173 Hannover, Germany and.
authors.forename: Anna
authors.initials: A
authors.lastname: Koczula
authors.affiliation: the Lehrstuhl für Biochemie, Technische Universität München, D-85747 Garching, Germany.
authors.forename: Birgit
authors.initials: B
authors.lastname: Lange
authors.affiliation: the Lehrstuhl für Biochemie, Technische Universität München, D-85747 Garching, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Eisenreich
authors.affiliation: From the Institute of Microbiology, University of Veterinary Medicine Hannover, D-30173 Hannover, Germany and.
authors.forename: Peter
authors.initials: P
authors.lastname: Valentin-Weigand
authors.affiliation: From the Institute of Microbiology, University of Veterinary Medicine Hannover, D-30173 Hannover, Germany and.
authors.forename: Ralph
authors.initials: R
authors.lastname: Goethe
mesh_terms: D000596:Amino Acids / Q000096:biosynthesis; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D053898:Biosynthetic Pathways / Q000235:genetics; D050260:Carbohydrate Metabolism / Q000235:genetics; D002244:Carbon / Q000378:metabolism*; D002247:Carbon Isotopes; D002455:Cell Division / Q000187:drug effects / Q000235:genetics; D003470:Culture Media / Q000737:chemistry / Q000494:pharmacology*; D004187:Disaccharides / Q000378:metabolism / Q000494:pharmacology; D005947:Glucose / Q000378:metabolism; D006019:Glycolysis / Q000187:drug effects; D009005:Monosaccharides / Q000378:metabolism / Q000494:pharmacology; D009154:Mutation; D062907:Oxaloacetic Acid / Q000378:metabolism; D010728:Phosphoenolpyruvate / Q000378:metabolism; D010730:Phosphoenolpyruvate Carboxylase / Q000235:genetics / Q000378:metabolism; D013290:Streptococcal Infections / Q000382:microbiology / Q000662:veterinary; D017011:Streptococcus suis / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism*; D013552:Swine; D013553:Swine Diseases / Q000097:blood / Q000134:cerebrospinal fluid / Q000382:microbiology
chemical_list: D000596:Amino Acids; D001426:Bacterial Proteins; D002247:Carbon Isotopes; D003470:Culture Media; D004187:Disaccharides; D009005:Monosaccharides; D062907:Oxaloacetic Acid; D010728:Phosphoenolpyruvate; D002244:Carbon; D010730:Phosphoenolpyruvate Carboxylase; D005947:Glucose
keywords: Amino Acid; Bacterial Metabolism; Biosynthesis; Carbohydrate Metabolism; Glycolysis; Isotopologue Profiling; Phosphoenolpyruvate Carboxylase; Streptococcus suis