In large metropolitan areas, which typically have the highest rates of gonorrhea, the identification of chains of transmission by use of partner notification is problematic, and there is an increasing interest in applying molecular approaches, which would require new discriminatory high-throughput procedures for recognizing clusters of indistinguishable gonococci, procedures that identify local chains of transmission. Sequencing of internal fragments of 2 highly polymorphic loci, from 436 isolates recovered in London during a 3-month period, identified clusters of antibiotic-resistant and antibiotic-susceptible isolates with indistinguishable genotypes, the vast majority of which were also identical or closely related by other methods, and defined groups of individuals who typically had similar demographic characteristics. This discriminatory sequence-based approach produces unambiguous data that easily can be compared via the Internet and appears to be suitable for the identification of linked cases of gonorrhea and the timely identification of transmission of antibiotic-resistant strains, even within large cities.
Bibliographical noteFunding Information:
Received 12 August 2003; accepted 22 October 2003; electronically published 31 March 2004. Presented in part: 15th Biennial Congress of the International Society for Sexually Transmitted Diseases Research, Ottawa, Canada, 27–30 July 2003 (abstract 0216). Financial support: UK Department of Health (grant to the study and separate funding to C.A.I. and B.G.S.); Wellcome Trust (bioinformatic support). B.G.S. is a Principal Research Fellow of the Wellcome Trust. The views expressed in the publication are those of the authors and are not necessarily those of the UK Department of Health. Reprints or correspondence: Dr. Iona M. C. Martin, Sexually Transmitted Bacteria Reference Laboratory, SRMD, Health Protection Agency, 61 Colindale Ave., London NW9 5HT, UK (email@example.com).