AUTHOR=Razooqi Zeinab , Tjellström Ingeborg , Höglund Åberg Carola , Kwamin Francis , Claesson Rolf , Haubek Dorte , Johansson Anders , Oscarsson Jan 

TITLE=Association of Filifactor alocis and its RTX toxin gene ftxA with periodontal attachment loss, and in synergy with Aggregatibacter actinomycetemcomitans

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=14

YEAR=2024

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2024.1376358

DOI=10.3389/fcimb.2024.1376358

ISSN=2235-2988

ABSTRACT=<p>The Gram-positive bacterium, <italic>Filifactor alocis</italic> is an oral pathogen, and approximately 50% of known strains encode a recently identified repeat-in-toxin (RTX) protein, FtxA. By assessing a longitudinal Ghanaian study population of adolescents (10-19 years of age; mean age 13.2 years), we recently discovered a possible correlation between deep periodontal pockets measured at the two-year follow-up, presence of the <italic>ftxA</italic> gene, and a high quantity of <italic>F. alocis</italic>. To further understand the contribution of <italic>F. alocis</italic> and FtxA in periodontal disease, we used qPCR in the present study to assess the carriage loads of <italic>F. alocis</italic> and the prevalence of its <italic>ftxA</italic> gene in subgingival plaque specimens, sampled at baseline from the Ghanaian cohort (n=500). Comparing these results with the recorded clinical attachment loss (CAL) longitudinal progression data from the two-year follow up, we concluded that carriers of <italic>ftxA</italic>-positive <italic>F. alocis</italic> typically exhibited higher loads of the bacterium. Moreover, high carriage loads of <italic>F. alocis</italic> and concomitant presence of the <italic>ftxA</italic> gene were two factors that were both associated with an enhanced prevalence of CAL progression. Interestingly, CAL progression appeared to be further promoted upon the simultaneous presence of <italic>F. alocis</italic> and the non-JP2 genotype of <italic>Aggregatibacter actinomycetemcomitans</italic>. Taken together, our present findings are consistent with the notion that <italic>F. alocis</italic> and its <italic>ftxA</italic> gene promotes CAL during periodontal disease.</p>