title: GC-MS based metabolomics for rapid simultaneous detection of Escherichia coli O157:H7, Salmonella Typhimurium, Salmonella Muenchen, and Salmonella Hartford in ground beef and chicken.
abstract: A metabolomic-based method for rapid detection of Escherichia coli O157:H7, Salmonella Hartford, Salmonella Typhimurium, and Salmonella Muenchen in nonselective media was developed. All pathogenic bacteria were grown in tryptic soy broth (TSB) at 37 °C followed by metabolite quantification at 2-h intervals for 24 h. Results were compared with the metabolite profiles similarly obtained with E. coli K12, Pseudomonas aeruginosa, Staphylococcus aureus, Saccharomyces cereviseae, and Aspergillus oryzae grown individually or as a cocktail under the same conditions. Principal component analysis (PCAS) discriminated pathogenic microorganisms grown in TSB. Metabolites responsible of PCAS classification were dextrose, cadaverine, the aminoacids L-histidine, glycine, and L-tyrosine, as well as the volatiles 1-octanol, 1-propanol, 1butanol, 2-ethyl-1-hexanol, and 2,5-dimethyl-pyrazine. Partial least square (PLS) models based on the overall metabolite profile of each bacteria were able to detect the presence of Escherichia coli O157:H7 and Salmonella spp. at levels of approximately 7 ± 2 CFU/25 g of ground beef and chicken within 18 h.
authors.affiliation: Univ. of Florida, IFAS, Citrus Research and Education Center, Food Science and Human Nutrition, Lake Alfred, FL, USA.
authors.forename: Juan Manuel
authors.initials: JM
authors.lastname: Cevallos-Cevallos
authors.forename: Michelle D
authors.initials: MD
authors.lastname: Danyluk
authors.forename: José I
authors.initials: JI
authors.lastname: Reyes-De-Corcuera
mesh_terms: D000818:Animals; D002417:Cattle; D002645:Chickens; D019453:Escherichia coli O157 / Q000254:growth & development / Q000302:isolation & purification*; D005506:Food Contamination / Q000032:analysis*; D005516:Food Microbiology / Q000379:methods; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D008460:Meat / Q000382:microbiology*; D055432:Metabolomics / Q000379:methods*; D025341:Principal Component Analysis; D015203:Reproducibility of Results; D012475:Salmonella / Q000145:classification / Q000254:growth & development / Q000302:isolation & purification*