Frequent "contaminants" detected during mycobacterial culture of decontaminated samples are bacteria of the order Actinomycetales. These are usually bacteria classified as the family Corynebacterineae, genera Corynebacterium, Dietzia, Gordonia, Nocardia, Rhodococcus and Tsukamurella.
These bacteria frequently colonize the airways and, under certain circumstances, they may cause lifethreatening diseases.