title: The role of thiamine in Yersinia kristensenii resistance to antibiotics and heavy metals.
abstract: The resistance to divalent metal ions, antibiotics and H2O2 was investigated in Yersinia kristensenii strains 13, 15, 18 by performing subcultivations with CdSO4 (20 and 100 mg/L) in nutrient agar (NA) and M9 medium with thiamine. Metal resistance of all three strains in NA was the same and decreased in the following sequence: Ni > Zn = Co > Cd. The chloramphenicol (Cmp) resistance ranged between 32 and 256 mg/L and the H2O2 sensitivity was very low or even zero. In the presence of thiamine the metal resistance sequence changed to Zn = Cd > Ni, Co, Ni and Co tolerance being 10-20 mg/L. Cmp resistance of all strains increased to 256 mg/L and H2O2 sensitivity also rose. In Cd-treated cultures, the ratio of glucose to thiamine in culture medium affected Cd resistance. At normal content of glucose and thiamine (5 g/L and 5 mg/L), Cd resistance markedly decreased coincident with thiamine exhaustion in these slowly-growing cultures. The Cmp resistance decreased to 16 mg/L, Ni and Co intolerance and H2O2 hypersensitivity appeared. At lowered glucose or thiamine levels (5 g/L and 2.5 mg/L or 2.5 g/L and 5 mg/L) a marginal decrease of Cd resistance took place in response to limited glucose uptake. Low thiamine or low-glucose cultures were resistant to H2O2, and exhibited a small decrease in Cmp resistance and a low Ni, Co tolerance. The adaptation of strain 15 to Cd induced only a small decrease of Cd resistance. Lowered glucose-to-thiamine ratio in culture medium probably induced in Cd-treated cultures a response triggering Cd resistance.
authors.affiliation: Institute of Preventive and Clinical Medicine, Bratislava.
authors.forename: H
authors.initials: H
authors.lastname: Hustavová
authors.forename: D
authors.initials: D
authors.lastname: Havraneková
mesh_terms: D002104:Cadmium / Q000494:pharmacology; D002413:Cations, Divalent / Q000494:pharmacology; D002702:Chloramphenicol Resistance / Q000502:physiology; D004352:Drug Resistance, Microbial / Q000502:physiology*; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D019216:Metals, Heavy / Q000494:pharmacology*; D018384:Oxidative Stress; D013831:Thiamine / Q000502:physiology*; D015007:Yersinia / Q000187:drug effects* / Q000378:metabolism
chemical_list: D002413:Cations, Divalent; D019216:Metals, Heavy; D002104:Cadmium; D006861:Hydrogen Peroxide; D013831:Thiamine