DNA AMPLIFICATION FINGERPRINTING FOR SUBTYPING NEISSERIA-GONORRHOEAE STRAINS

Background and Objectives: DNA amplification fingerprinting is used in most epidemiologic studies as a substitute for conventional typing me thods. DNA amplification fingerprinting and conventional typing method s were compared in this epidemiologic study of Neisseria gonorrhoeae. Goal of This Study: To differentiate 70 Neisseria gonorrhoeae isolates from untreated patients with urogenital gonococcal infection. Study D esign: Gonococcal strains were characterized by auxotyping, serotyping , plasmid profile, antibiotic sensitivity, and DNA amplification finge rprinting. The method of unweighted pair-group average linkage was use d for fluster analysis. Discriminatory power was calculated applying S impson's index. Results: Amplification of Neisseria gonorrhoeae DNA wi th primers OPA-03 and OPA-13 produced well-resolved patterns of 15 and 22 DNA fragments, respectively, with a discriminatory power (0.978 wi th OPA-13 and 0.967 with OPA-03) comparable to that obtained with auxo typing/serotyping combination (D:0.968) or with auxotype/serotype/plas mid profile combination (D:0.983). Correlation between DNA amplificati on fingerprinting pattern and auxotype/serotype class was not always u niform. Some strains with the same auxotype/serotype/plasmid profile w ere subdivided by DNA amplification fingerprinting, and vice versa. Co nclusion: Although auxotype/serotype class and DNA amplification finge rprinting can be used in the epidemiologic characterization of strains , DNA amplification fingerprinting offers a better discriminatory inde x than the separate serotyping. It is especially useful for differenti ating serologically identical strains and nontypable strains. A combin ation of serotyping and DNA amplification fingerprinting seems to be t he best way to differentiate Neisseria gonorrhoeae strains in epidemio logic studies, bringing together the most simple techniques and the be st discriminatory power among isolates.