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The cagE gene sequence as a diagnostic marker to identify JP2 and non-JP2 highly leukotoxic Aggregatibacter
A Johansson1, R Claesson2, C Höglund Åberg1
1Division of Molecular Periodontology, Department of Odontology, Umeå University, Umeå, Sweden.
Background And Objective:
Aggregatibacter actinomycetemcomitans is involved in oral and systemic infections, and is associated with, eg aggressive forms of periodontitis and with endocarditis. The cagE gene encodes a ≈39 kDa putative exotoxin expressed by A. actinomycetemcomitans. The level of conservation of cagE, and its possible significance in periodontal disease, has not yet been thoroughly investigated. In the present study, the role of the cagE gene as a diagnostic marker has been investigated.
Material And Methods:
We have used conventional polymerase chain reaction (PCR), quantitative PCR and whole genome sequencing data to determine the prevalence of cagE in A. actinomycetemcomitans based on analysis of: (i) 249 isolates, collected and cultivated in a Ghanaian longitudinal cohort study; (ii) a serotype b collection of 19 strains; and (iii) the 36 A. actinomycetemcomitans genomes available in the NCBI database.
Results:
Whereas cagE was absent in the other serotypes, our data support that this gene sequence is linked to a virulent and highly leukotoxic group of serotype b strains, including both JP2 and non-JP2 genotypes of A. actinomycetemcomitans.
Conclusion:
We propose that cagE has the potential to be used as a PCR-based gene marker for the identification of a virulent and highly leukotoxic group of serotype b strains, including both JP2 and non-JP2 genotypes. This finding might be of importance in the risk assessment of the development of periodontal attachment loss in young individuals and hence suggested to be a relevant discovery in future development of new diagnostic tools and/or treatment strategies.
Insights
The cagE gene is linked to virulent, leukotoxic Aggregatibacter actinomycetemcomitans serotype b strains. This gene may serve as a diagnostic marker for identifying strains associated with periodontal disease risk.
Area of Science:
- Microbiology
- Genetics
- Oral Health
Background:
- Aggregatibacter actinomycetemcomitans causes oral and systemic infections, including aggressive periodontitis and endocarditis.
- The cagE gene encodes a putative exotoxin in A. actinomycetemcomitans, but its conservation and significance in periodontal disease are not well understood.
Purpose of the Study:
- Investigate the prevalence and role of the cagE gene in A. actinomycetemcomitans.
- Evaluate the potential of cagE as a diagnostic marker for virulent strains.
Main Methods:
- Utilized conventional PCR, quantitative PCR, and whole genome sequencing.
- Analyzed 249 isolates from a Ghanaian cohort, 19 serotype b strains, and 36 publicly available A. actinomycetemcomitans genomes.
Main Results:
- The cagE gene was absent in A. actinomycetemcomitans serotypes other than serotype b.
- The cagE gene sequence is associated with a virulent and highly leukotoxic group of serotype b strains, encompassing both JP2 and non-JP2 genotypes.
Conclusions:
- The cagE gene can potentially serve as a PCR-based diagnostic marker for identifying virulent, highly leukotoxic serotype b strains of A. actinomycetemcomitans.
- This finding is significant for assessing the risk of periodontal attachment loss in young individuals and may inform new diagnostic tools and treatment strategies.
