Complex sentence: Glycopeptide resistance is mediated by acquisition of the "vanA" gene, which originates from the enterococci and codes for an enzyme that produces an alternative peptidoglycan to which vancomycin will not bind.
Split into simpler sentences: Glycopeptide resistance is mediated by acquisition of the "vanA" gene. The "vanA" gene originates from the "enterococci" and codes for an enzyme that produces an alternative peptidoglycan to which vancomycin will not bind.