Complex sentence: Enterotoxigenic Escherichia coli (ETEC) is a type found to cause illness in humans, possessing gene that allows it to manufacture a substance toxic to humans.
Split into simpler sentences: Enterotoxigenic Escherichia coli (ETEC) is a type of bacteria that causes illness in humans. ETEC is a special kind of E. Coli which has a gene that allows it to manufacture a substance toxic to humans.