Seminar #5: New discoveries in temperate bacteriophages

Temperate Bacteriophages are for life, not just for Christmas – 16/12/16

Dr. Darren L Smith [Source: Northumbria University]

Presented by Dr. Darren L Smith, Senior Lecturer in Biology within the Department of Applied Biology, Cellular and Molecular Sciences/Microbiology Group, University of Northumbria

The Seminar:

Dr. Darren L Smith presented a seminar on genomic discoveries of temperate bacteriophages.

Temperate bacteriophage refers to a bacteria-affecting virus which has a lysogenic life cycle, and most can integrate their genome into the bacterial genome.

There is a population of 1028 bacteria, and 1031 bacteriophages, 1023 of which intimate a new infection every second.

After being infected, stress to the bacteria causes a switch to a virus-producing life cycle.

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Replication Cycle of Bacteriophages [Source: Luke Fears]
The first zoonotic pathogen, Shigatoxigenic E. coli, causes symptoms by changing the epithelial cells or the gut.

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Symptoms of a Shigatoxigenic E. coli infection [Source: Luke Fears]
One of Dr. Smith’s PhD students found a new development – that Shigatoxigenic E. coli cells infected by temperate bacteriophages exhibit rapid cell growth.

The study used a Biolog, which includes a series of tests for Na+ salts produced by respiration. A colour change indicates a change in respiration rate.

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Biolog results of Dr. Smith’s studies of gene expression in E.coli [Source: Luke Fears]
When analysing the genomes of lysogens, genes of unknown functions tend to be associated with the productive side if the phage – most of genes are turned on during lysogenic infection.

As a result of mutation and natural selection, some bacterial phases are able to function in the presence of anti-bacterial compounds.

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Biolog results for respiration rates of E. coli utilising various substrates [Source: Luke Fears]
However said viruses are now unable to use beta-D-Allose as a respiration substrate.

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Biolog results for respiration rates of E. coli utilising various substrates, including b-D-Allose, which E. coli is no longer able to respire [Source: Luke Fears]
My Opinions:

I knew very little of temperate bacteriophages apart from basic micro biology, so I found this more detailed insight interesting.

However, I found myself confused often due to my lack of in-depth knowledge, so I couldn’t appreciate the full scope of the discoveries made.

Dr Smith however did present his seminar with great enthusiasm; a sign that he likely enjoys his work.

How this affects my career choices:

This seminar didn’t affect my career choices to a great extent, as it has little to do with the subjects in which I am interested.

However it has reinforced my wariness of pursuing employment involving detailed analysis of genomes, especially those of bacteria.

However, Dr. Smith’s enthusiastic presentation has further motivated me into a career pursuing research.

Dr. Darren Smith’s University of Northumbria Profile

Biolog Home Page

Dr. Darren Smith’s Research Papers


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