<prompt> The bacteria frequently used as an immunomodulator isCorynebacterium parvumMycobacterium marinumChromobacterium violasiumFlavobacterium meningosepticum  <response>: Corynebacterium parvum, which is frequently used as an immunomodulator, is a mixture of the Propionibacterium species. Reference: Textbook of Microbiology; Anathanarayan and panickers; 10th edition; Page no: 246 