Pulsed-field gel electrophoresis for genomic analysis of Neisseria gonorrhoeae.

Pulsed-field gel electrophoresis (PFGE) is a technique for analyzing large DNA fragments. PFGE was compared to auxotyping and Por serovar (A/S) classification to determine its utility in the study of gonococcal infection, subtyping A/S classes, and clone identification. PFGE patterns were stable in vitro after 2 isolates were passaged 50 times, and those from sex partners were indistinguishable with both enzymes. Fourteen proline-requiring IA-6 isolates from Kenya produced 8 NheI and 7 XbaI patterns; these included 6 Tet M-carrying isolates, all producing the same NheI pattern. PFGE patterns of 14 arginine-, hypoxanthine-, and uracil-requiring IA-1,2 isolates, from the US Pacific Northwest and Hawaii in 1993, were less diverse with both enzymes. PFGE analysis represents a potentially useful addition to the current gonococcal classification system.