Occurrence of Aggregatibacter actinomycetemcomitans serotypes in subgingival plaque from United States subjects

Abstract

This study examined the distribution pattern of Aggregatibacter actinomycetemcomitans serotypes in the subgingival plaque of subjects residing in the United States. A. actinomycetemcomitans was identified in 256 subgingival plaque samples from 161 subjects. For 190 of the 256 samples, the total cultivable bacteria and selected periodontal pathogenic species were determined. A. actinomycetemcomitans isolates were confirmed by a16S rDNA-based PCR analysis, genotyped by arbitrarily-primed PCR, and serotyped by PCR analysis of serotype-specific gene clusters. A total of 82 distinct A. actinomycetemcomitans strains were identified. The serotype distribution pattern of the strains was 21 (25.6%) serotype a, 12 (14.6%) b, 41 (50%) c, 6 (7.3%) e, 1 (1.2%) f, and 1 (1.2%) non-typeable. For 14 subjects where multiple colonies of A. actinomycetemcomitans were identified, 11 subjects (78.6%) were each infected by a single serotype, while the remaining three subjects (21.3%) were each infected by two serotypes of A. actinomycetemcomitans. There was an inverse relationship between the level of cultivable A. actinomycetemcomitans and Porphyromonas gingivalis. Within subgingival plaque of study cohort A. actinomycetemcomitans serotype c was the dominant serotype and comprised 50% of all strains, followed by (in order of detection frequency) serotypes a and b. Serotypes d, e, and f strains were either not detected or less frequently found. Serotype distribution patterns of subgingival A. actinomycetemcomitans may vary among subjects of different race orethnicity.

Aggregatibacter actinomycetemcomitans serotypes infections and periodontal conditions: a two-way assessment

“…As showed by several authors [9,10,17,18] the distribution pattern of A. actinomycetemcomitans serotypes varies greatly depending on the periodontal status of the allocated population and the country where the study takes place. Up to now, in Brazil, as well as in Latin America, no study had recruited a considerable number of subjects showing plaque samples positive for A. actinomycetemcomitans, and a diversity of periodontal conditions.…”

“…However, researchers don't seem to have observed a similar serotype-disease pattern. Recently, Chen et al [9] examined the distribution pattern of A. actinomycetemcomitans serotypes in the subgingival plaque of subjects residing in the United States and demonstrated that serotype c is the dominant serotype in this population. The authors also observed that serotype a was more frequently detected than serotypes b, d, e, and f. Non-typeable strains were either not detected or were relatively infrequent in the examined population.…”

Aggregatibacter actinomycetemcomitans: Virulence of its leukotoxin and association with aggressive periodontitis

“…73,74 These findings are supported by the negative association in subgingival samples between the presence of A. actinomycetemcomitans and P. gingivalis. 75 This indicates an important pre-clinical role of A. actinomycetemcomitans in AgP. However, it seems reasonable to assume that the role of this bacterium is limited in competition with the obligate anaerobic periodontal pathogens in the ecological niche of a periodontal crevice.…”

Function of the enterobactin operon of A. actinomycetemcomitans in the presence of catecholmines and iron.

“…Recently, a study conducted in the United States in 2010 observed all serotypes in the oral cavities of the participants, in varying distributions [36]. Serotype 'c' was the dominant serotype, followed by 'a' and 'b'.…”

“…Serotypes 'd' and 'e' were rare, while the prevalence of 'f' is still under investigation [37]. Additionally, patients may harbor just one serotype, or several [36].…”