title: Enterobacter sakazakii bacteriophages can prevent bacterial growth in reconstituted infant formula.
abstract: Reconstituted infant formula has been implicated in outbreaks of Enterobacter sakazakii infections, causing high mortality and serious sequelae. Current prevention methods appear to be insufficient to ensure that such foods are free of E. sakazakii. In this study, the usefulness of bacteriophages for biocontrol of E. sakazakii was investigated. Of a total of six new E. sakazakii phages isolated from sewage and UV irradiated cultures, two were selected for further study by electron microscopy, DNA restriction analysis and SDS-PAGE of structural proteins. Purified phages were used to control bacterial growth in broth medium and reconstituted infant formula. Both phages effectively prevented development of E. sakazakii in formula at various temperatures (12, 24 and 37 degrees C), the efficiency of which was dependent upon intrinsic lysis properties and the applied phage concentration. We conclude that application of specific bacteriophages may provide a means for efficient prevention of E. sakazakii infection through reconstituted infant formula.
authors.affiliation: Food Microbiology Laboratory, Institute of Food Science and Nutrition, Schmelzbergstrasse 7, ETH Zurich, 8092 Zurich, Switzerland.
authors.forename: Kwang-Pyo
authors.initials: KP
authors.lastname: Kim
authors.forename: Jochen
authors.initials: J
authors.lastname: Klumpp
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Loessner
mesh_terms: D001419:Bacteria / Q000254:growth & development*; D001435:Bacteriophages / Q000502:physiology*; D015169:Colony Count, Microbial; D044083:Cronobacter sakazakii / Q000254:growth & development*; D004269:DNA, Bacterial / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel; D005506:Food Contamination / Q000517:prevention & control*; D005516:Food Microbiology; D006801:Humans; D007223:Infant; D041943:Infant Formula / Q000592:standards; D007231:Infant, Newborn; D013696:Temperature; D013997:Time Factors
chemical_list: D004269:DNA, Bacterial