Distribution of Porphyromonas gingivalis fimA genotypes in primary endodontic infections.
OBJECTIVE
Long fimbriae (FimA) are important virulence factors of Porphyromonas gingivalis. Based on the diversity of the fimA gene, this species is classified into 6 genotypes. This study surveyed samples from primary endodontic infections for the presence of these P. gingivalis fimA variants.


METHODS
Genomic DNA isolated from samples taken from 25 root canals of teeth with chronic apical periodontitis and 25 aspirates from acute apical abscess was used as template in polymerase chain reaction (PCR) assays directed toward the detection of the different P. gingivalis fimA genotypes.


RESULTS
Porphyromonas gingivalis was detected by a 16S rRNA gene-based PCR in 36% of the total number of cases sampled (44% of chronic apical periodontitis and 28% of abscess aspirates). In cases of chronic apical periodontitis, P. gingivalis variant type IV was the most prevalent (24%), followed by types I (20%), II (16%), and III (8%). In acute abscess samples, variant type II was the most prevalent (12%), followed by types III and IV (8% of each) and type I (4%). Combinations of up to 3 different genotypes were detected in a few cases. No single fimA genotype variant or combination thereof was significantly associated with symptoms. Overall, fimA types IV (16%), II (14%), and I (12%) were the most prevalent.


CONCLUSIONS
Findings demonstrated that different P. gingivalis fimA genotypes can be present in primary endodontic infections.
Rôças
Isabela N
IN
Department of Endodontics and Molecular Microbiology Laboratory, Faculty of Dentistry, Estácio de Sá University, Rio de Janeiro, Brazil.
Siqueira
José F
JF
D016866:Bacteroidaceae Infections / Q000382:microbiology*; D055113:Chronic Periodontitis / Q000382:microbiology*; D036781:Fimbriae Proteins / Q000235:genetics*; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D010482:Periapical Abscess / Q000382:microbiology*; D010485:Periapical Periodontitis / Q000382:microbiology*; D016966:Porphyromonas gingivalis / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D012329:RNA, Bacterial / Q000032:analysis
D012329:RNA, Bacterial; D036781:Fimbriae Proteins