PAEP and bacterial vaginosis: While a single amino acid mutation was identified in the external domain of gD that affected the stability of binding to nectin 1, comparison of gD sequences from 19 clinical BV strains isolated from humans and macaques found that this mutation did not correlate with zoonosis [117], indicating that differing stability of gD binding to nectin 1 is not related to the ability of BV to infect human versus macaque cells.