Hi Ardilles! Bacteriophage tails have fibers on their ends, allowing them to attach to the host bacteria. The tail acts as a transport to move DNA from the capsid head into the host bacteria to prepare for replication. All tails follow this same purpose, but different phage families have different structures. Myoviridae tails are shorter, contractile, and fairly thick. This structure may be beneficial because myoviridaes often have larger heads than other phages (Virus Taxonomy, 2012). The tails of Siphoviridae are much more thin and flexible, likely serving a different evolutionary purpose (though due to their flexibility, these tails have been difficult to characterize and study, so I’m not sure exactly how this affects the phage). Most of all, different tail lengths and structures can help us group phages into families and clusters, adding more samples and information into the SEA Phages database for further study and potential therapeutic benefits.
Hi Ana! We did not actually utilize PCR in this research. What you’re seeing on the poster is a restriction digest. The bands on this digest are able to tell us which enzymes effectively cut our high quality + quantity phage DNA. From this, we are able to compare the amounts of cuts per enzyme to other bacteriophages on a database (Phage Enzyme Tools). From the database, we can determine which phages are the most similar to ours, and based on these similar phages’ clusters, we can predict which cluster ours belongs to. Our plaques are very appropriate when we look at our phage — based on other research regarding lytic siphoviridae phages, our plaques and morphologies are quite similar to results seen in other research.
Great poster! What are the implications of your phage being lytic? Is a phage with that life cycle better or worse for future use in phage-based treatment?
Hi Lia! Because our phage is lytic, this means it is able to fully lyse and kill bacteria, unlike a temperate phage, which may choose to embed itself into the genome of the host bacteria (therefore keeping the bacteria alive). To use temperate phages in phage therapy, a few extra steps are needed to remove repressor and embedding proteins from the phage, therefore it is much simpler to use a lytic phage for phage treatments.
Hi Noemi! Different types of plaques tell us how different phages function. This knowledge of function is crucial when understanding how to prepare phage to use in phage therapy — we want how they work before administering them to patients. Turbid plaques mean that we have a temperate phage embedding itself into the genome, while clear hole-punch-like plaques mean the phage is lytic, so it fully clears and kills all bacteria. Recently, bulls-eye plaques have been discovered, where bacteria will survive in the middle of the plaque, but the edges will be clear. This indicates less lytic ability, occurring when bacteria is stronger/more prolific than the phage, or even with an inhibition phenotype seen occasionally in different phages. Plaque size can also tell us how efficient/strong a phage is. I believe that studying phages of different strengths can help us understand how to dose bacteriophages in phage therapy.
curesymposium.org 
How do tail lengths affect the phage?
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Hi Ardilles! Bacteriophage tails have fibers on their ends, allowing them to attach to the host bacteria. The tail acts as a transport to move DNA from the capsid head into the host bacteria to prepare for replication. All tails follow this same purpose, but different phage families have different structures. Myoviridae tails are shorter, contractile, and fairly thick. This structure may be beneficial because myoviridaes often have larger heads than other phages (Virus Taxonomy, 2012). The tails of Siphoviridae are much more thin and flexible, likely serving a different evolutionary purpose (though due to their flexibility, these tails have been difficult to characterize and study, so I’m not sure exactly how this affects the phage). Most of all, different tail lengths and structures can help us group phages into families and clusters, adding more samples and information into the SEA Phages database for further study and potential therapeutic benefits.
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What could you conclude looking at your PCR bands? Do you think that the phage morphology was befitting with your plaque results?
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Hi Ana! We did not actually utilize PCR in this research. What you’re seeing on the poster is a restriction digest. The bands on this digest are able to tell us which enzymes effectively cut our high quality + quantity phage DNA. From this, we are able to compare the amounts of cuts per enzyme to other bacteriophages on a database (Phage Enzyme Tools). From the database, we can determine which phages are the most similar to ours, and based on these similar phages’ clusters, we can predict which cluster ours belongs to. Our plaques are very appropriate when we look at our phage — based on other research regarding lytic siphoviridae phages, our plaques and morphologies are quite similar to results seen in other research.
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Great poster! What are the implications of your phage being lytic? Is a phage with that life cycle better or worse for future use in phage-based treatment?
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Hi Lia! Because our phage is lytic, this means it is able to fully lyse and kill bacteria, unlike a temperate phage, which may choose to embed itself into the genome of the host bacteria (therefore keeping the bacteria alive). To use temperate phages in phage therapy, a few extra steps are needed to remove repressor and embedding proteins from the phage, therefore it is much simpler to use a lytic phage for phage treatments.
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Why are plaque shapes important to study in the future?
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Hi Noemi! Different types of plaques tell us how different phages function. This knowledge of function is crucial when understanding how to prepare phage to use in phage therapy — we want how they work before administering them to patients. Turbid plaques mean that we have a temperate phage embedding itself into the genome, while clear hole-punch-like plaques mean the phage is lytic, so it fully clears and kills all bacteria. Recently, bulls-eye plaques have been discovered, where bacteria will survive in the middle of the plaque, but the edges will be clear. This indicates less lytic ability, occurring when bacteria is stronger/more prolific than the phage, or even with an inhibition phenotype seen occasionally in different phages. Plaque size can also tell us how efficient/strong a phage is. I believe that studying phages of different strengths can help us understand how to dose bacteriophages in phage therapy.
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