title: Use of Ensure® nutrition shakes as an alternative formulation method for live recombinant Attenuated Salmonella Typhi vaccines.
abstract: BACKGROUND
  To be effective, orally administered live Salmonella vaccines must first survive their encounter with the low pH environment of the stomach. To enhance survival, an antacid is often given to neutralize the acidic environment of the stomach just prior to or concomitant with administration of the vaccine. One drawback of this approach, from the perspective of the clinical trial volunteer, is that the taste of a bicarbonate-based acid neutralization system can be unpleasant. Thus, we explored an alternative method that would be at least as effective as bicarbonate and with a potentially more acceptable taste. Because ingestion of protein can rapidly buffer stomach pH, we examined the possibility that the protein-rich Ensure® Nutrition shakes would be effective alternatives to bicarbonate.
  
  
  RESULTS
  We tested one Salmonella enterica serovar Typhimurium and three Salmonella Typhi vaccine strains and found that all strains survived equally well when incubated in either Ensure® or bicarbonate. In a low gastric pH mouse model, Ensure® worked as well or better than bicarbonate to enhance survival through the intestinal tract, although neither agent enhanced the survival of the S. Typhi test strain possessing a rpoS mutation.
  
  
  CONCLUSIONS
  Our data show that a protein-rich drink such as Ensure® Nutrition shakes can serve as an alternative to bicarbonate for reducing gastric pH prior to administration of a live Salmonella vaccine.
authors: The Biodesign Institute, Arizona State University, Tempe, AZ, 85287, USA. karenbrenneman1@gmail.com.|Present address - 23andMe, Inc, 1390 Shorebird Way, Mountain View, CA, 94043, USA. karenbrenneman1@gmail.com.
authors: Karen E
authors: KE
authors: Brenneman
authors: The Biodesign Institute, Arizona State University, Tempe, AZ, 85287, USA. Amanda.Gonzales@asu.edu.
authors: Amanda
authors: A
authors: Gonzales
authors: The Biodesign Institute, Arizona State University, Tempe, AZ, 85287, USA. kenneth.roland@asu.edu.
authors: Kenneth L
authors: KL
authors: Roland
authors: The Biodesign Institute, Arizona State University, Tempe, AZ, 85287, USA. rcurtiss@asu.edu.|School of Life Sciences, Arizona State University, Tempe, AZ, 85287, USA. rcurtiss@asu.edu.
authors: Roy
authors: R
authors: Curtiss
mesh_terms: D000818:Animals; D000863:Antacids / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics; D019422:Dietary Sucrose / Q000737:chemistry / Q000494:pharmacology*; D004195:Disease Models, Animal; D005526:Food, Formulated; D015870:Gene Expression; D006863:Hydrogen-Ion Concentration; D051379:Mice; D050296:Microbial Viability / Q000187:drug effects; D009154:Mutation; D012480:Salmonella Infections / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control*; D022562:Salmonella Vaccines / Q000008:administration & dosage / Q000276:immunology*; D012485:Salmonella typhi / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development / Q000276:immunology; D012486:Salmonella typhimurium / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development / Q000276:immunology; D012808:Sigma Factor / Q000172:deficiency / Q000235:genetics; D017693:Sodium Bicarbonate / Q000494:pharmacology; D013270:Stomach / Q000737:chemistry; D014611:Vaccination; D014613:Vaccines, Attenuated
chemical_list: D000863:Antacids; D001426:Bacterial Proteins; D019422:Dietary Sucrose; D022562:Salmonella Vaccines; D012808:Sigma Factor; D014613:Vaccines, Attenuated; C069567:sigma factor KatF protein, Bacteria; C082131:Ensure formulated food; D017693:Sodium Bicarbonate