<prompt> Nocardia is differentiated from Actinomyces by:Gram stainZN stainNocardia causes mycetoma, Actinomyces do notNocardia is facultative anaerobe  <response>: Ans. is b i.e., Ziehl Neelsen stainRef: Ananthanarayan, 8the, p. 393; 9the, p. 394; Harrison, 18the, p. 1324; Jawetz, 24the, p. 182Nocardia - Partially acid fast, obligate aerobe, habitat is soil and infections occur exogenously.Actinomyces - Nonacid fast, facultative anaerobe, habitat is oral flora so infections occur endogenously. 