<prompt> Which organism cannot be cultured in cell-free mediaKlebsiella rhinoscleromatisKlebsiella ozaenaeTreponema pallidumSporothrix schenckii  <response>: Treponema cannot be grown in aificial culture media but is maintained by subculture in susceptible animals. Sporothrix is a dimorphic fungus, that form yeast in tissues at 37C and the mycelial phase in the culture at 25C. Klebsiella grows on ordinary media. Reference: Textbook of Microbiology; Ananthanarayan and panikers; 10th edition; Pg: 379 