Complex sentence: Of the over 100 documented species in the genus "Mycoplasma", 14 are known to infect humans, which is expected as the Mollicutes are common commensals or pathogens of several different organisms.
Split into simpler sentences: Of the over 100 documented species in the genus "Mycoplasma", 14 are known to infect humans. This comes as no surprise, as the Mollicutes are common commensals or pathogens of several different organisms.