A. actinomycetemcomitans profile and red complex bacterial species of an Afro-Brazilian community: A comparative study.
PURPOSES
The primary aim of this cross-sectional study was to compare the levels of red complex bacteria between Afro-Brazilian and non Afro-Brazilian cohort. The secondary aim was to compare the distribution of both Aggregatibacter actinomycetemcomitans serotype b and its JP2 strains among participants who harboured this bacterial species.


METHODS
A total of 84 individuals were included in this study: 42 Afro-descendants (mean age 35.9 ± 13.1 years) and 42 non-Afro-descendants (mean age 36.2 ± 13.1 years) matched (1:1) by periodontal diagnosis, age and gender. All participants received clinical examinations of periodontal pocket depth, clinical attachment level, and plaque and gingival indices. Subgingival samples were taken for microbial analysis. First, genomic DNA (gDNA) was extracted and purified and the quantification of total number of bacterial cells, A. actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola was carried out by qPCR. Then, A. actinomycetemcomitans strains were classified according to serotype b and JP2 profiles by conventional PCR.


RESULTS
Clinically, mean PD, mean CAL and percentage of CAL ≥ 3 mm differed between groups (Student's t-test p<0.05). The levels of red complex bacteria between Afro-Brazilian and non-Afro-Brazilian populations were similar. The exception was verified to A. actinomycetemcomitans showing significantly higher levels among Afro-Brazilian descendants in comparison to non-Afro-Brazilian descendants. Afro-Brazilian descendants were clearly infected by more virulent serotype b and JP2 strains.


CONCLUSIONS
Despite no statistically significant differences related to the red complex species, Afro-Brazilian descendants harboured higher levels of A. actinomycetemcomitans. Also, our findings confirm that Afro-descendant populations are preferably colonised by A. actinomycetemcomitans serotype b as well as JP2 strains.
['de Araujo Neris|Murilo|M|', 'Cortelli|Sheila Cavalca|SC|', 'Aquino|Davi Romeiro|DR|', 'de Miranda|Taís Browne|TB|', 'Costa|Fernando de Oliveira|Fde O|', 'Cortelli|José Roberto|JR|']
D000328:Adult D016976:Aggregatibacter actinomycetemcomitans D001439:Bacteroides D044383:Blacks D001938:Brazil D003430:Cross-Sectional Studies D005260:Female D006801:Humans D008297:Male D010518:Periodontitis D016133:Polymerase Chain Reaction D016966:Porphyromonas gingivalis D012703:Serotyping D048373:Treponema denticola
Bacteria Serotype Periodontitis Ethnic groups Leucotoxin