Dynamics of appearance and expansion of a prolyliminopeptidase- negative subtype among Neisseria gonorrhoeae isolates collected in Sydney, Australia, from 2002 to 2005.

Recent studies have demonstrated a wide geographic circulation of isolates of Neisseria gonorrhoeae that fail to produce prolyliminopeptidase (PIP). Tests based on the production of this enzyme are important elements of a number of identification systems for gonococci. We documented the appearance, expansion, and contraction of subtypes of 165 PIP-negative gonococci detected in an extended and systematic sample of the 3,926 N.