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Background: Isolates of Neisseria gonorrhoeae requiring arginine, hypoxanthine, and uracil (AHU) appeared in Denmark in 1946, were preponderant in Seattle during the 1970s, were associated with disseminated gonococcal infections (DGI), and were primarily of the IA-1,2 serovar. Goals: To investigate the disappearance of the AHU/IA-1,2 phenotype and to examine by pulsed-field gel electrophoresis (PFGE) the genomic homogeneity of this unique phenotype isolated from Seattle-King County during the past decade. Study Design: This retrospective study used data extracted from previous publications for the period 1971 through 1984, and from existing records at the Neisseria Reference Laboratory, University of Washington for the period 1985 through 1996. Samples (n = 68) of AHU/IA-1,2 isolates from 1984 to 1985 and 1988 to 1993 were analyzed using endonucleases NheI and XbaI. For comparison, 10 AHU/IB isolates were included in the study. Results: AHU isolates, predominantly IA-1,2 strains accounted for 52% of the gonococcal isolates for the period 1971 through 1974, 40% for 1974 through 1976, 16% for 1984, and then declined from 7% in 1986 to 0% for each of the last 3 years, 1994 through 1996. Isolates with [is less than or equal to] band difference after digestion with either NheI or XbaI were considered to belong to a single closely related pattern. Pulsed-field gel electrophoresis (PFGE) type designation was made from the combination of NheI and XbaI patterns. These criteria yielded 5 NheI and 8 XbaI PFGE patterns, and 11 PFGE types based on the combination of NheI and XbaI pattern. The most frequently occurring NheI and XbaI patterns accounted for 74% and 57% of isolates, respectively. One type persisted throughout the decade and accounted for 54% of the 68 isolates. Analysis of the 10 AHU/IB isolates yielded 7 NheI and 8 XbaI patterns that gave 9 types that were distinct from the types found in the AHU/IA-1,2 strains. Conclusion: The AHU/IA-1,2 phenotype first documented 50 years ago in Denmark still shows a high degree of genomic homogeneity during the past decade in Seattle. The implementation of screening, decreased rates of sexual exposure in the acquired immune deficiency syndrome era, or other factors may explain its apparent elimination in Seattle-King County., The selective disappearance of a particular strain of Neisseria gonorrhoeae, AHU/IA-1,2, from the Seattle area could be related to its remarkable genetic uniformity. This strain accounted for 52% of the gonorrhea cases reported in Seattle-King County during 1971 through 1974. Fewer were found in subsequent years, and none of this type of Neisseria was identified from 1994 through 1996. Sixty-eight AHU/IA-1,2 samples were examined for genetic diversity and found to be notably unvarying when compared with 10 isolates of another type, AHU/IB. The possible role of this uniformity in the organism's survival is not yet understood.

Funding for this project was provided by the National Institute of Dental and Craniofacial Research, National Institutes of Health, Grant #U54 DE14254. Purpose. Streptococcus mutans is the primary organism associated with dental caries, an infectious, bacterial, and multi-factorial disease that remains the world's most common biofilm-related dental disease. However, the relationship between caries experience and the salivary mutans streptococci (MS) load is controversial By understanding this relationship, we might better link caries activity to microbial diagnostic tests and improve caries management. This study aims to determine if caries experience in children is associated with salivary bacterial load of MS. Methods and Materials. We acquired adult institutional review board consent from parents and consent from their children to conduct oral examinations and collect buccal and salivary samples. A total of 149 children (88 female, 61 male; 11-15 years) were recruited. Overall, the children were healthy, with 91.8% having no history of major disease. Most children had permanent dentition (80.4%). The children presented with no decay (35%), low decay (32%, Results. To date, 29 samples have been assayed, 16 from the high-caries group and 13 from the no-caries group. The high-caries children showed detectable salivary MS at dilutions of 102 and 103, while the no-caries group showed a wide distribution of detection ranging from 102 to 106. Thus, the high-caries group had lower levels of salivary MS than the group with no caries. One possible explanation for this surprising result is that MS in high-caries children may have greater adherence to teeth and, therefore, have low concentrations in saliva. Conclusion. These results emphasize the multi-factorial nature of the dental caries process in which bacteria, diet, oral hygiene, and genetic factors all contribute to the overall risk for caries., Kimberly K. Mathieu, RDH, MS, is a graduate student at the University of Washington. Marilyn C. Roberts, PhD, is an associate professor at the University of Washington. Norma J. Wells, [...]