| SMHBZ8 | |
|---|---|
 | |
| TEM image of a SMHBZ8 virion | |
Virus classification  | |
| (unranked): | Virus |
| Realm: | Duplodnaviria |
| Kingdom: | Heunggongvirae |
| Phylum: | Uroviricota |
| Class: | Caudoviricetes |
| Family: | Aliceevansviridae |
| Virus: | SMHBZ8 |
SMHBZ8 is a lytic bacteriophage that infects the bacteria Streptococcus mutans . [1] [2] [3] The virus was isolated in 2020. [1]
Transmission electron microscopy (TEM) found SMHBZ8 to have a B1 morphology with an isometric head diameter of approximately 56 nm, a long non-contractile tail with an approximate length of 244 nm, and a tail width of 10.9 nm. [1]
Whole genome sequencing revealed a genome size of 32,460 base pairs. Analysis indicated that SMHBZ8 appeared to be related to other S. mutans phages, including M102, M102AD, and APCM01. While all four phages shared approximately 75% sequence identity, core gene analysis identified only seven genes fully conserved across all genomes. SMHBZ8 possessed 32 unique genes compared to the other phages, with two unique genes coding for lysins (QKE60409.1 and QKE60410.1) being identified. [1] [4]
SMHBZ8 has been studied as a possible phage therapy agent to treat tooth decay by infecting and causing lysis in Streptococcus mutans, a key bacteria that produces acid leading to decay. Preclinical studies showed that it was able to reduce existing biofilms in dentin samples. [1] [2] [3]
A bacteriophage, also known informally as a phage, is a virus that infects and replicates within bacteria and archaea. The term was derived from "bacteria" and the Greek φαγεῖν, meaning "to devour". Bacteriophages are composed of proteins that encapsulate a DNA or RNA genome, and may have structures that are either simple or elaborate. Their genomes may encode as few as four genes and as many as hundreds of genes. Phages replicate within the bacterium following the injection of their genome into its cytoplasm.
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Corticovirus is a genus of viruses in the family Corticoviridae. Corticoviruses are bacteriophages; that is, their natural hosts are bacteria. The genus contains two species. The name is derived from Latin cortex, corticis. However, prophages closely related to PM2 are abundant in the genomes of aquatic bacteria, suggesting that the ecological importance of corticoviruses might be underestimated. Bacteriophage PM2 was first described in 1968 after isolation from seawater sampled from the coast of Chile.
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