title: Effect of iron concentration on toxin production in Campylobacter jejuni and Campylobacter coli.
abstract: The effect of iron concentrations in culture media on supernatant yields of campylobacter cytotonic toxin (CCT) was studied. Of the 118 Campylobacter spp. strains surveyed, 78.8% produced toxin in brucella broth or in casamino acids--yeast extract (CYE) broth. When the iron concentration of CYE was increased from 0.44 microgram/mL (7.9 microM) to 0.65 microgram/mL (11.6 microM) by the addition of ferric chloride, 94.9% of the strains were positive for toxin in a ganglioside GM1 based, enzyme-linked immunosorbent assay, using antibody to affinity-purified CCT. The addition of iron as ferrous sulfate was less effective. When four toxin-positive strains were grown in a deferrated medium of conalbumin-treated CYE with 0.04-0.08 microgram iron/mL (0.72-1.43 microM), two of the culture supernatants became negative (absorbance at 410 nm, less than 0.1 and less than 10 ng CCT/mL), and two produced about 90% less CCT but were still classified as positive (absorbance, greater than or equal to 0.1 and greater than or equal to 10 ng CCT/mL). It was therefore concluded that the production of CCT by Campylobacter spp. is influenced by iron concentration.
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000096:biosynthesis*; D002167:Campylobacter / Q000378:metabolism*; D002168:Campylobacter fetus / Q000378:metabolism*; D002460:Cell Line; D002470:Cell Survival; D003470:Culture Media; D003603:Cytotoxins / Q000096:biosynthesis*; D004797:Enzyme-Linked Immunosorbent Assay; D007501:Iron / Q000494:pharmacology*; D051379:Mice
chemical_list: D001427:Bacterial Toxins; D003470:Culture Media; D003603:Cytotoxins; D007501:Iron