Sequencing, Assembling, and Finishing Complete Bacteriophage Genomes

Complete genome sequence of Microbacterium paraoxydans phage Damascus

Phage Damascus was isolated from soil in northwestern Wisconsin using Microbacterium paraoxydans as the host. The Damascus genome is 56,477 bp with 3' single-stranded overhangs and 56.5% G+C content. Damascus was assigned to cluster EL and shares 42.6%-91.7% gene content with the three other phages in this cluster.

Genome sequences of actinobacteriophages JorRay, Blocker23, Nibbles, and OlgasClover

JorRay, Blocker23, Nibbles, and OlgasClover are actinobacteriophages belonging to clusters G1, B2, CT, and DJ, respectively. JorRay and Blocker23 were identified in host bacterium Mycobacterium smegmatis mc2155. Nibbles and OlgasClover were identified in host bacterium Gordonia rubripertincta NRRL B-16540.

Genome sequence and annotation of Arthrobacter globiformis phage Ruchi (AS1) isolated from soil in Lumpkin County, Georgia

Ruchi, a temperate, AS1 subcluster bacteriophage isolated in Lumpkin County, Georgia using host Arthrobacter globiformis, possesses a genome of 38,571 bp and 67.7% GC. Annotation of this virus revealed 64 predicted reading frames, no predicted tRNA genes, and a close evolutionary relationship to AS1 phage Basilisk.

Desert diversity: genome sequence of Gordonia rubripertincta cluster DJ phage Mossy and cluster DV phage Erutan

Lytic bacteriophages Mossy and Erutan were directly isolated from desert soil on Gordonia rubripertincta and characterized by their morphologies and genomes. Mossy, part of the DJ cluster of Actinobacteriophage, has a genome of 61,183 bp. The genome of Erutan, part of the DV cluster, is 66,957 bp.

Complete genome and characteristics of cluster BC bacteriophage SoJo, isolated using Streptomyces mirabilis NRRL B-2400 in Columbia, MD

Here, we present bacteriophage SoJo, a siphovirus infecting Streptomyces mirabilis, with a circularly permuted genome of 39 kbp and GC content of 71.5%. Its genome length and content are similar to that of other phages in the Actinobacteriophage Database BC cluster. SoJo was isolated from soil in Columbia, MD, USA.

Complete genome sequence of Mycobacterium smegmatis phage Rummer, a subcluster A3 actinophage

Bacteriophage Rummer is a siphovirus morphology actinophage isolated from Mycobacterium smegmatis. Rummer has a 50,908 base pair genome encoding 89 predicted protein-coding genes and three tRNAs. Based on gene content similarity to sequenced actinobacteriophages, Rummer is assigned to phage subcluster A3.

Genome sequence of Soos: a siphovirus of the CP cluster infecting Gordonia rubripertincta

Novel actinobacteriophage Soos was isolated and purified from Southern Indiana soil using host Gordonia rubripertincta NRRL B-16540. Sequencing revealed a 57,509 bp circularly permuted genome encoding 87 predicted protein-coding genes. Soos is only the third phage in cluster CP, along with phages Clawz and Sting.

The genomic characterization of three Microbacterium foliorum-specific bacteriophages, "Nucci," "MCubed," and "QMacho"

Nucci, MCubed, and QMacho are microbacteriophages that were isolated from soil samples in Charlotte, NC. They were classified into EA10, EA2, and EB clusters, respectively. Nucci and MCubed each had 63 predicted genes, while QMacho had 73 predicted genes.

Genome sequence and annotation of Arthrobacter globiformis phage Vulpecula (AS1) isolated from soil in Dahlonega, Georgia

Vulpecula, a temperate bacteriophage collected from soil in Dahlonega, Georgia using host Arthrobacter globiformis, is an AS1 subcluster virus of 37,766 bp (67.7% GC). Genome annotation suggests 64 open reading frames, no predicted tRNA genes, and ~98% sequence similarity to AS1 phages Ruchi (from GA) and Jamun (New Hampshire).

Genome sequence of Arthrobacter globiformis phage MaGuCo

MaGuCo is a temperate phage isolated from soil collected in Alton, NH, USA, using Arthrobacter globiformis. Its genome is 43,924 base pairs long and contains 63 protein-encoding genes, 44 of which were assigned putative functions. MaCuGo is assigned to cluster AZ2 based on gene content similarity to actinobacteriophages.

Complete genome sequence of the Microbacterium foliorum bacteriophage Garey24

In this work, we report the discovery and characterization of Garey24, a bacteriophage that forms medium-size plaques with halo rings isolated from a soil sample in Funes, Argentina. Its 41,522 bp circularly permuted genome contains 63 putative protein-coding genes. Based on gene content similarity, Garey24 was assigned to subcluster EA1.

Genome sequence of bacteriophage Djungelskog isolated from an Arthrobacter globiformis culture

Actinobacteriophage Djungelskog was isolated from a sample of degraded organic material in Poughkeepsie, NY, using Arthrobacter globiformis B-2979. Its genome is 54,512 bp and encodes 86 putative protein-coding genes. Djungelskog has a siphovirus morphology and is assigned to cluster AW based on gene content similarity to actinobacteriophages.

Complete genome sequences of bacteriophages Guetzie and SirVictor, isolated from Microbacterium foliorum

Cluster EA4 Guetzie and SirVictor are lytic siphoviral bacteriophages that were isolated from soil in Waverly, Iowa, using Microbacterium foliorum NRRL B-24224 as the host. The Guetzie and SirVictor genomes are both 39,758 bp each, and both contain 58 predicted protein-coding genes with one tRNA gene each.

Genome sequence of PSonyx, a singleton bacteriophage infecting Corynebacterium glutamicum

PSonyx is a newly isolated phage that infects Corynebacterium glutamicum. This siphovirus was isolated from a French pond in the south of Paris by students from Paris-Saclay University. Its 80,277-bp singleton genome carries 136 protein-coding genes and 5 tRNAs.

Genome sequences of Microbacterium foliorum phages, BabyYoda and Lynlen

BabyYoda and Lynlen are two cluster EB phages that were discovered at Thiel College using Microbacterium foliorum NRRL B-24224. Both BabyYoda and Lynlen are predicted to be lytic, with siphovirus morphologies, with genome sizes of 41,557 and 41,448 base pairs, respectively.

Genome sequence of Microbacterium foliorum phage CandC

We report the discovery and genome sequence of CandC, a lytic bacteriophage with siphovirus morphology. CandC was isolated from a soil sample from Plattsburgh, NY, USA (Fall 2021). It has a genome size of 62,344 bp with 106 predicted protein-encoding genes, 30 of which are assigned putative functions.

From Cullowhee Creek to Conley: genome sequence and annotation of a cluster DJ Gordonia phage

We report the discovery of Gordonia phage Conley, a siphovirus isolated from Cullowhee Creek in the Fall of 2022. The 60,078bp genome contains 90 predicted protein-coding genes all transcribed in the same direction and has been assigned to genetic cluster DJ based on gene content similarity.

From compost to culver: genome sequence and annotation of a cluster CQ1 Gordonia phage

Phage Culver, with a siphovirus morphology, was isolated using Gordonia terrae CAG3. Culver is assigned to phage cluster CQ1 based on gene content similarity to actinobacteriophages. Notably, Culver is predicted to encode eight tRNAs, lysin A by two adjacent genes, and, unlike other CQ1 phages, two putative integrase genes.

Complete genome sequences of nine Rhodococcus equi phages

We report genomes of nine phages isolated from Actinobacteria Rhodococcus equi NRRL B-16538. Six of these phages belong to actinobacteriophage cluster CR, which otherwise contains Gordonia phages; two form the CF cluster; and one is a singleton. Genome lengths are 62,017-80,980 bp with 63.9%-67.3% GC content.

Complete Genome Sequences of Four Mycobacteriophages Involved in Directed Evolution against Undisputed Mycobacterium abscessus Clinical Strains

Phage therapy is still in its infancy, but it is increasingly promising as a future alternative for treating antibiotic-resistant bacteria. To investigate the effect of phages on Mycobacterium abscessus complex (MABC), we isolated 113 environmental phages, grown them to high titres, and assayed them on MABC clinical strains through the spot test. Of all the phages, only 16 showed killing activity. Their activity was so temperate to MABC that they could not generate any plaque-forming units (PFUs). The Appelmans method of directed evolution was carried out to evolve these 16 phages into more lytic ones. After only 11 of 30 rounds of evolution, every single clinical strain in our collection, including those that were unsusceptible up to this point, could be lysed by at least one phage. The evolved phages were able to form PFUs on the clinical strains tested. Still, they are temperate at best and require further training. The genomes of one random parental phage and three random evolved phages from Round 13 were sequenced, revealing a diversity of clusters and genes of a variety of evolutionary origins, mostly of unknown function. These complete annotated genomes will be key for future molecular characterisations.

A prophage encoded ribosomal RNA methyltransferase regulates the virulence of Shiga-toxin-producing Escherichia coli (STEC)

Shiga toxin (Stx) released by Shiga toxin producing Escherichia coli (STEC) causes life-threatening illness. Its production and release require induction of Stx-encoding prophage resident within the STEC genome. We identified two different STEC strains, PA2 and PA8, bearing Stx-encoding prophage whose sequences primarily differ by the position of an IS629 insertion element, yet differ in their abilities to kill eukaryotic cells and whose prophages differ in their spontaneous induction frequencies. The IS629 element in ϕPA2, disrupts an ORF predicted to encode a DNA adenine methyltransferase, whereas in ϕPA8, this element lies in an intergenic region. Introducing a plasmid expressing the methyltransferase gene product into ϕPA2 bearing-strains increases both the prophage spontaneous induction frequency and virulence to those exhibited by ϕPA8 bearing-strains. However, a plasmid bearing mutations predicted to disrupt the putative active site of the methyltransferase does not complement either of these defects. When complexed with a second protein, the methyltransferase holoenzyme preferentially uses 16S rRNA as a substrate. The second subunit is responsible for directing the preferential methylation of rRNA. Together these findings reveal a previously unrecognized role for rRNA methylation in regulating induction of Stx-encoding prophage.

Complete genome sequences of Streptomyces griseus phages Spelly and Phredrick

We present the complete genome sequences of two viruses with siphovirus morphology, isolated from soils collected in Southwestern Indiana using the host Streptomyces griseus. Spelly is a BE2 cluster phage with a 131,347-bp genome. Phredrick is a BK1 cluster phage with a 128,873-bp genome.

Genome sequences of 31 mycobacteriophages isolated on Mycobacterium smegmatis mc2155 at room temperature

We report the genome sequences of 31 mycobacteriophages isolated on Mycobacterium smegmatis mc2155 at room temperature. The genomes add to the diversity of Clusters A, B, C, G, and K. Collectively, the genomes include 70 novel protein-coding genes that have no close relatives among the actinobacteriophages.

Complete genome sequences and characteristics of mycobacteriophages Diminimus, Dulcita, Glaske16, and Koreni

Complete genome sequences of four novel mycobacteriophages, Diminimus, Dulcita, Glaske16, and Koreni, isolated from soil are presented. All these bacteriophages belong to subcluster M1, except Koreni that belongs to subcluster A4. Moreover, all have siphovirus morphologies, with genome sizes ranging from 51,055 to 81,156 bp.

Genome sequences of bacteriophage Shambre1 and Renna12, isolated from Arthrobacter globiformis

Bacteriophages Shambre1 and Renna12 were isolated from soil in Bismarck, ND, using Arthrobacter globiformis. Genomic characterization and analyses allowed Renna12 to be assigned to phage cluster AS3, while Shambre1, which is not closely related to any phage, is a singleton.

Genome sequence of the lytic bacteriophage Alucard, a cluster EE actinophage

Bacteriophage Alucard is a lytic phage isolated from the soil collected in southern Maine on Microbacterium foliorum NRRL B-24224. Alucard has siphovirus morphology with a 17,363-bp genome encoding 25 putative genes. Based on gene content similarity to actinobacteriophages, Alucard is assigned to cluster EE.

Characterization of the genomes of cluster CT Gordonia terrae phages, Horseradish and Yummy

The genomes of lytic, cluster CT Gordonia terrae phages, Horseradish and Yummy, are 45,764 and 45,878 bp in length, respectively, and each encodes 71 protein-coding genes. The genomes are identical in sequence with the exception of a 38-bp insertion/deletion in the minor tail protein, gp26.

Characterization and genome sequence of Microbacterium foliorum phage Morrigan, of cluster EA6 with siphovirus morphology

Bacteriophage Morrigan, which was isolated from soil using Microbacterium foliorum NRRL B-24224, is lytic with siphovirus morphology. Morrigan's 40,509-bp genome has a GC content of 62.8% and 66 putative protein-coding genes, of which 31 could be assigned putative functions. Based on gene content similarity to actinobacteriophages, Morrigan is assigned to subcluster EA6.

Genome sequence of Microbacterium foliorum bacteriophage DumpQuist isolated from soil in Clarksville, Tennessee

Bacteriophage DumpQuist was isolated from soil collected in Clarksville, TN, using the bacterium Microbacterium foliorum. Electron microscopy revealed that DumpQuist has a podovirus morphology. DumpQuist has a 53,924-bp genome that contains 54 predicted protein-coding genes and is most similar to phages in actinobacteriophage cluster EK1.

Genome sequences of cluster GA phages Phonegingi and Dropshot

Bacteriophages Phonegingi and Dropshot were isolated from soil in North Carolina using the host Microbacterium foliorum. Both phages have siphovirus morphologies. Based on gene content similarity to one another and to other actinobacteriophages, both phages are assigned to phage cluster GA.

Isolation and genome sequence annotation of SallyK, a newly discovered cluster EG bacteriophage infecting Microbacterium

Discovered from soil in a flower planter in Pocatello, Idaho and using Microbacterium foliorum, SallyK is a lytic bacteriophage with a siphovirus morphology. It has a 62,883 bp-long genome with 103 putative genes. Based on gene content similarity to actinobacteriophages, SallyK is assigned to cluster EG.

A Novel Subcluster of Closely Related Bacillus Phages with Distinct Tail Fiber/Lysin Gene Combinations

Bacteriophages (phages) are the most numerous entities on Earth, but we have only scratched the surface of describing phage diversity. We isolated seven Bacillus subtilis phages from desert soil in the southwest United States and then sequenced and characterized their genomes. Comparative analyses revealed high nucleotide and amino acid similarity between these seven phages, which constitute a novel subcluster. Interestingly, the tail fiber and lysin genes of these phages seem to come from different origins and carry out slightly different functions. These genes were likely acquired by this subcluster of phages via horizontal gene transfer. In conjunction with host range assays, our data suggest that these phages are adapting to hosts with different cell walls.

Genomic sequence identification of Arthrobacter phage Ascela

Arthrobacter phage Ascela was isolated in North Georgia. Its genome is 44,192 bp with 71 open reading frames and a GC content of 67.4%. It shares 99.29% nucleotide identity with Arthrobacter phage Iter. Actinobacteriophages that share over 50% nucleotide identity are sorted into clusters, with Ascela in cluster AZ and subcluster AZ1.

Genome sequence of Streptomyces BM cluster phage Frankenweenie

Frankenweenie is a newly isolated bacteriophage that infects Streptomyces scabiei RL-34. Frankenweenie was discovered in Gaithersburg, MD, and has 366 genes comprising a 200,048-bp genome. Frankenweenie is grouped in cluster BM and is predicted to possess a unique tailspike protein that potentially widens its host range.

Isolation and genome sequence annotation of KillerTomato, a newly discovered cluster EE bacteriophage infecting Microbacterium

Discovered in Pocatello, Idaho, soil near a tomato garden, siphovirus KillerTomato infects Microbacterium foliorum NRRL B-24224. KillerTomato is a lytic cluster EE phage with a 17,442-bp genome and 68.6% GC content. Of 25 genes, 20 were assigned putative functions, including a putative tail assembly chaperone protein with a programmed frameshift and an endolysin.

Genome sequence of bacteriophage Aoka, a cluster FO phage isolated using Arthrobacter globiformis

We report the discovery and genome sequence of bacteriophage Aoka, an actinobacteriophage isolated from a soil sample in Pueblo, Colorado using Arthrobacter globiformis, B2880-SEA. Its genome length is 36,744 base pairs with 54 protein-coding genes. Based on gene content similarity to other actinobacteriophages, Aoka is assigned to cluster FO.

Isolating and characterizing cluster AB Mycobacteriophage NoShow, which encodes lysis proteins shared with cluster H2 phages

We present here Mycobacteriophage NoShow, isolated from a soil sample collected on the Maguire Campus of Saint Joseph's University in Merion Station, Pennsylvania. Even though NoShow's 52,825 bp genome is most similar to phages in cluster AB, its lysA and lysB genes are most similar to phages in cluster H2.

Complete genome sequence of phi29-like Microbacterium foliorum podovirus phage PineapplePizza

Bacteriophage PineapplePizza is a podovirus infecting Microbacterium foliorum NRRL B-24224. The genome is 16,662 bp long and contains 23 predicted protein-coding genes. Interestingly, PineapplePizza shows amino acid similarities to well-studied Bacillus subtilis phage phi29.

Complete genome sequences of Gordonia rubripertincta phages OtterstedtS21 and Patos

We report the genomes of two viruses with siphovirus morphology, OtterstedtS21 and Patos, from Albany, New York, using Gordonia rubripertincta. The genomes of OtterstedtS21 and Patos are ~68 kbp long with 58% GC content. Both phages group with cluster DV based on gene content similarity to phages in the Actinobacteriophage database.

Mycobacteriophage Rita: a cluster F1 phage discovered in North Easton, Massachusetts

Mycobacteriophage Rita infects Mycobacterium smegmatis mc2155 and was isolated from a soil sample collected in North Easton, Massachusetts. Assigned to cluster F1 based on sequence similarity to other phages in the same cluster, Rita has a 58,771 bp genome and encodes 104 genes. Rita is 98% similar to phage Bipolar.

Isolation, characterization, and genome analysis of a broad host range Salmonella phage vB_SenS_TUMS_E4: a candidate bacteriophage for biocontrol

Salmonella enteritidis is one of the most important foodborne pathogens that cause numerous outbreaks worldwide. Some strains of Salmonella have become progressively resistant to antibiotics, so they could represent a critical threat to public health and have led to the use of alternative therapeutic approaches like phage therapy. In this study, a lytic phage, vB_SenS_TUMS_E4 (E4), was isolated from poultry effluent and characterized to evaluate its potential and efficacy for bio-controlling S. enteritidis in foods. Transmission electron microscopy revealed that E4 has a siphovirus morphotype, with an isometric head and non-contractile tail. Determining the host range showed that this phage can effectively infect different motile as well as non-motile Salmonella enterica serovars. The biological characteristics of E4 showed that it has a short latent period of about 15 min and a large burst size of 287 PFU/cell, and is also significantly stable in a broad range of pHs and temperatures. The E4 whole genome contains 43,018 bp and encodes 60 coding sequences (CDSs) but no tRNA genes. Bioinformatics analysis revealed that the genome of E4 lacks any genes related to lysogeny behavior, antibiotic resistance, toxins, or virulence factors. The efficacy of phage E4 as a bio-control agent was assessed in various foodstuffs inoculated with S. enteritidis at 4°C and 25°C, and the resulting data indicated that it could eradicate S. enteritidis after a very short time of 15 min. The findings of the present study showed that E4 is a hopeful candidate as a bio-control agent against S. enteritidis and has the potential to be used in various foodstuffs.

Therapeutically useful mycobacteriophages BPs and Muddy require trehalose polyphleates

Mycobacteriophages show promise as therapeutic agents for non-tuberculous mycobacterium infections. However, little is known about phage recognition of Mycobacterium cell surfaces or mechanisms of phage resistance. We show here that trehalose polyphleates (TPPs)-high-molecular-weight, surface-exposed glycolipids found in some mycobacterial species-are required for infection of Mycobacterium abscessus and Mycobacterium smegmatis by clinically useful phages BPs and Muddy. TPP loss leads to defects in adsorption and infection and confers resistance. Transposon mutagenesis shows that TPP disruption is the primary mechanism for phage resistance. Spontaneous phage resistance occurs through TPP loss by mutation, and some M. abscessus clinical isolates are naturally phage-insensitive due to TPP synthesis gene mutations. Both BPs and Muddy become TPP-independent through single amino acid substitutions in their tail spike proteins, and M. abscessus mutants resistant to TPP-independent phages reveal additional resistance mechanisms. Clinical use of BPs and Muddy TPP-independent mutants should preempt phage resistance caused by TPP loss.

Isolation, Characterization, and Comparative Genomic Analysis of Bacteriophage Ec_MI-02 from Pigeon Feces Infecting Escherichia coli O157:H7

The most significant serotype of Shiga-toxigenic Escherichia coli that causes foodborne illnesses is Escherichia coli O157:H7. Elimination of E. coli O157:H7 during food processing and storage is a possible solution. Bacteriophages have a significant impact on bacterial populations in nature due to their ability to lyse their bacterial host. In the current study, a virulent bacteriophage, Ec_MI-02, was isolated from the feces of a wild pigeon in the United Arab Emirates (UAE) for potential future use as a bio-preservative or in phage therapy. Using a spot test and an efficiency of plating analysis, Ec_MI-02 was found to infect in addition to the propagation host, E. coli O157:H7 NCTC 12900, five different serotypes of E. coli O157:H7 (three clinical samples from infected patients, one from contaminated green salad, and one from contaminated ground beef). Based on morphology and genome analysis, Ec_MI-02 belongs to the genus Tequatrovirus under the order Caudovirales. The adsorption rate constant (K) of Ec_MI-02 was found to be 1.55 × 10^-8 mL/min. The latent period was 50 min with a burst size of almost 10 plaque forming units (pfu)/host cell in the one-step growth curve when the phage Ec_MI-02 was cultivated using the propagation host E. coli O157:H7 NCTC 12900. Ec_MI-02 was found to be stable at a wide range of pH, temperature, and commonly used laboratory disinfectants. Its genome is 165,454 bp long with a GC content of 35.5% and encodes 266 protein coding genes. Ec_MI-02 has genes encoding for rI, rII, and rIII lysis inhibition proteins, which supports the observation of delayed lysis in the one-step growth curve. The current study provides additional evidence that wild birds could also be a good natural reservoir for bacteriophages that do not carry antibiotic resistance genes and could be good candidates for phage therapy. In addition, studying the genetic makeup of bacteriophages that infect human pathogens is crucial for ensuring their safe usage in the food industry.

Genome Sequence of Gordonia terrae Phage APunk

Gordonia phage APunk was isolated from soil collected in Grand Rapids (MI, USA) using Gordonia terrae 3612. The genome of APunk is 59,154 bp long, has a 67.7% GC content, and contains 32 protein-coding genes. Based on its gene content similarity to actinobacteriophages, APunk is assigned to phage cluster DE4.

Genome Sequences of Five Microbacterium foliorum Phages, GaeCeo, NeumannU, Eightball, Chivey, and Hiddenleaf

Five siphoviruses were isolated from soil in southeastern Pennsylvania using Microbacterium foliorum. Bacteriophages NeumannU and Eightball have 25 predicted genes, Chivey and Hiddenleaf have 87 genes, and GaeCeo has 60 genes. Based on gene content similarity to sequenced actinobacteriophages, these five phages are distributed across clusters EA, EE, and EF.

PCR Assay for Rapid Taxonomic Differentiation of Virulent Staphylococcus aureus and Klebsiella pneumoniae Bacteriophages

Phage therapy is now seen as a promising way to overcome the current global crisis in the spread of multidrug-resistant bacteria. However, phages are highly strain-specific, and in most cases one will have to isolate a new phage or search for a phage suitable for a therapeutic application in existing libraries. At an early stage of the isolation process, rapid screening techniques are needed to identify and type potential virulent phages. Here, we propose a simple PCR approach to differentiate between two families of virulent Staphylococcus phages (Herelleviridae and Rountreeviridae) and eleven genera of virulent Klebsiella phages (Przondovirus, Taipeivirus, Drulisvirus, Webervirus, Jiaodavirus, Sugarlandvirus, Slopekvirus, Jedunavirus, Marfavirus, Mydovirus and Yonseivirus). This assay includes a thorough search of a dataset comprising S. aureus (n = 269) and K. pneumoniae (n = 480) phage genomes available in the NCBI RefSeq/GenBank database for specific genes that are highly conserved at the taxonomic group level. The selected primers showed high sensitivity and specificity for both isolated DNA and crude phage lysates, which permits circumventing DNA purification protocols. Our approach can be extended and applied to any group of phages, given the large number of available genomes in the databases.

Mycobacterial nucleoid-associated protein Lsr2 is required for productive mycobacteriophage infection

Mycobacteriophages are a diverse group of viruses infecting Mycobacterium with substantial therapeutic potential. However, as this potential becomes realized, the molecular details of phage infection and mechanisms of resistance remain ill-defined. Here we use live-cell fluorescence microscopy to visualize the spatiotemporal dynamics of mycobacteriophage infection in single cells and populations, showing that infection is dependent on the host nucleoid-associated Lsr2 protein. Mycobacteriophages preferentially adsorb at Mycobacterium smegmatis sites of new cell wall synthesis and following DNA injection, Lsr2 reorganizes away from host replication foci to establish zones of phage DNA replication (ZOPR). Cells lacking Lsr2 proceed through to cell lysis when infected but fail to generate consecutive phage bursts that trigger epidemic spread of phage particles to neighbouring cells. Many mycobacteriophages code for their own Lsr2-related proteins, and although their roles are unknown, they do not rescue the loss of host Lsr2.

Isolation and Annotation of Xitlalli, a Cluster EK1 Actinobacteriophage Isolated Using Microbacterium foliorum

Xitlalli is an actinobacteriophage that was isolated from soil using Microbacterium foliorum. Based on gene content similarity to phages in the Actinobacteriophage Database, Xitlalli is assigned to cluster EK1. The genome is 53,929 bp long and contains 52 protein-coding genes, of which 26% could be assigned functions.

Complete Genome Sequence of the Microbacterium Bacteriophage Chako

We characterized the complete genome sequence of Chako, an obligate lytic bacteriophage with siphovirus morphology from subcluster EA1 that infects Microbacterium foliorum NRRL B-24224. Its 41.6-kb genome contains 62 putative protein-coding genes and is highly similar to that of bacteriophage HanSolo (99.26% nucleotide identity).

Unusual prophages in Mycobacterium abscessus genomes and strain variations in phage susceptibilities

Mycobacterium abscessus infections are relatively common in patients with cystic fibrosis and are clinically challenging, with frequent intrinsic resistance to antibiotics. Therapeutic treatment with bacteriophages offers some promise but faces many challenges including substantial variation in phage susceptibilities among clinical isolates, and the need to personalize therapies for individual patients. Many strains are not susceptible to any phages or are not efficiently killed by lytic phages, including all smooth colony morphotype strains tested to-date. Here, we analyze a set of new M. abscessus isolates for the genomic relationships, prophage content, spontaneous phage release, and phage susceptibilities. We find that prophages are common in these M. abscessus genomes, but some have unusual arrangements, including tandemly integrated prophages, internal duplications, and they participate in active exchange of polymorphic toxin-immunity cassettes secreted by ESX systems. Relatively few strains are efficiently infected by any mycobacteriophages, and the infection patterns do not reflect the overall phylogenetic relationships of the strains. Characterization of these strains and their phage susceptibility profiles will help to advance the broader application of phage therapies for NTM infections.