 However, resident microbes can cause skin diseases and enter the blood system, creating life-threatening diseases, particularly in immunosuppressed people.A major non-human skin flora is "Batrachochytrium dendrobatidis", a chytrid and non-hyphal zoosporic fungus that causes chytridiomycosis, an infectious disease thought to be responsible for the decline in amphibian populations.The estimate of the number of species present on skin bacteria has been radically changed by the use of 16S ribosomal RNA to identify bacterial species present on skin samples direct from their genetic material.