The drug resistance of Hydrogenobacter thermophilus strain TK-6

Abstract

Hydrogenobacter thermophilus is an extremely thermophilic and obligately autotrophic hydrogen-oxidising bacterium with various unusual properties and believed to occupy a unique taxonomic position. Inhibitory patterns of various antibiotics on the cell growth of H. thermophilus strain TK-6 clearly showed that the bacterium possessed prokaryote-type systems of DNA, RNA and protein syntheses. Effect of ionophore antibiotics supported that the bacterium was a Gram-negative bacterium, but high sensitivities against macrolide and some other antibiotics and insensitivity against polymyxin B were unusual as a Gram-negative eubacterium. Growth inhibition by cell wall synthesis inhibitors revealed the existence of peptidoglycan on the surface of H. thermophilus, but ineffectiveness of cell wall lytic enzymes (lysozyme and lysostaphin) on intact cells and purified cell wall strongly suggested the uniqueness of the cell wall structure of the bacterium.