**3. Aggregatibacter bacteriophages**

Aggregatibacter is the causative agent of localized aggressive periodontitis. Aggregatibacter phages are mostly temperate phages and easy to isolate. Engineered Aggregatibacter bacteriophages that release biofilm degrading enzymes like dispersion B to breakdown biofilm have been used against periodontitis causing *Aggregatibacter actinomycetemcomitans* [13]. ϕAa 17 and Aaϕ23 are the most extensively studied Aggregatibacter phages [14]. These Aaϕ phages have a relatively broad host range. The limitation of these Aggregatibacter phages is that they can transfer antibiotic resistance genes, which are acquired macrolide lincosamide streptogramin B (MLS) resistance genes such as erm (A), erm (B), erm (C), erm (F), and erm (Q ), and induce serotype conversion and release of leukotoxin [15]. In a recent study, it has been seen by metagenomics analysis that Aggregatibacter phages preferably lysogenize specific phylogenetic lineages not correlating with specific clinical conditions. They have either a very narrow host range or a broad host range [16]. The clinical conditions/impact in which these phages are used remains unknown.
