Mycobacteriophage

[3] Mycobacteriophages have served as examples of viral lysogeny and of the divergent morphology and genetic arrangement characteristic of many phage types.

Thus, phage GC% does not necessarily match that of its host, and the consequent mismatch of codon usage profiles does not appear to be detrimental.

Because new mycobacteriophages lacking extensive DNA similarity with the extant collection are still being discovered, and as there are at least seven singletons for which no relatives have been isolated, we clearly have yet to saturate the diversity of this particular population.

[9] The collection of >50,000 genes can be sorted into >3,900 groups (so-called phamilies, i.e. phage protein families) according to their shared amino acid sequences.

These mechanisms can be mediated through several processes like Clustered Regulatory Interspaced Short Palindromic Repeats (CRISPRs) and the translational apparatus being modified.

Comparisons of these sequences have helped to explain how frequently genetic exchanges of this type may occur in nature, as well as how phages may contribute to bacterial pathogenicity.

These genome sequences were grouped into clusters by several methods in an effort to determine similarities between the phages and to explore their genetic diversity.

A system has been developed to use mycobacteriophage carrying a reporter gene to screen strains of M. tuberculosis for antibiotic resistance.

[23][24] In 2019 it was reported that three mycobacteriophages were administered intravenously twice daily to a 15 year-old girl with cystic fibrosis and disseminated M. abscessus subsp.

[26] Airway cultures for M. abscessus became negative after approximately 100 days of combined phage and antibiotic treatment, and a variety of biomarkers confirmed the therapeutic response.

Mycobacteriophage Bxb1 Structure [ 1 ]
Figure 1. Diversity of mycobacteriophages. Sequenced genomes for 471 mycobacteriophages were compared according to their shared gene contents and overall nucleotide sequence similarity. Colored circles encompass Clusters A–T as indicated, and grey circles represent singleton genomes that have no close relatives. A1, A2, A3... indicate subclusters. Micrographs show the morphotypes of the myoviral Cluster C phages and the siphoviruses (all others) that primarily differ in tail length (scale bars: 100 nm). With the exception of DS6A (a singleton), all phages infect M. smegmatis mc2155. Cluster K phages and a subset of Cluster A phages also infect M. tuberculosis . From Hatfull 2014 [ 9 ]