title: Egg yolk emulsion agar, a new medium for the cultivation of Helicobacter pylori.
abstract: We developed a new agar, egg yolk emulsion (EYE) agar, for cultivation of Helicobacter pylori. EYE agar contains Columbia agar base (Oxoid), 10% EYE (Oxoid), 1% IsoVitaleX (BBL), and 40 mg of Triphenyleteraxolium chloride (Sigma) per liter. We compared EYE agar with the following agars: (i) brain heart infusion agar-7% horse blood-1% IsoVitaleX (GDW agar; C. S. Goodwin, E. D. Blincow, J. R. Warren, T. E. Waters, C. R. Sanderson, and L. Easton, J. Clin. Pathol. 38:1127-1131, 1985), (ii) brain heart infusion agar-10% horse serum-0.2% charcoal-1% yeast extract-40 mg of triphenyltetrazolium chloride per liter (GLU agar; Y. Glupczynski, M. Labbe, and F. Thiabaumont, p. 3-6, in F. Megraud and H. Lamouliatte, ed., Gastroduodenal Pathology and Campylobacter pylori, 1989), (iii) Columbia agar with 7% lysed horse blood (D&M agar; J. C. Dent and C. A. M. McNulty, Eur. J. Clin. Microbiol. Infect. Dis. 7:555-558, 1988), and (iv) brain heart infusion agar-10% EYE-1% IsoVitaleX (BHIE agar). H. pylori CFU counts, expressed as average percentages of maximum growth, were as follows: EYE agar, 96; GDW agar. 76; BHIE agar, 57; D&M agar, 52; and GLU agar, 23. Colony counts for EYE agar were significantly higher than for GDW agar (P = 0.027), BHIE agar (P = 0.005), D&M agar (P = 0.0001), and GLU agar (P less than 0.0001). EYE agar also had higher CFU counts than two commercial chocolate media; the EYE agar count was 80%, versus 33% for BBL chocolate medium and 63% for Remel chocolate medium.
authors.affiliation: Department of Medicine, St. Louis University School of Medicine, Missouri 63104.
authors.forename: T U
authors.initials: TU
authors.lastname: Westblom
authors.forename: E
authors.initials: E
authors.lastname: Madan
authors.forename: B R
authors.initials: BR
authors.lastname: Midkiff
mesh_terms: D000362:Agar; D003470:Culture Media; D004530:Egg Yolk; D004655:Emulsions; D016480:Helicobacter pylori / Q000254:growth & development*
chemical_list: D003470:Culture Media; D004655:Emulsions; D000362:Agar