Exploding bacteria for science!!!

As the Chief Medical Officer, Professor Dame Sally Davies, highlights today “danger posed by growing resistance to antibiotics should be ranked along with terrorism on a list of threats to the nation”. Professor Dame Sally Davies said diseases are evolving faster than the drugs that exist to treat them and antibiotic resistance is “a ticking time bomb“.

This is a subject of great interest to scientists in ICaMB, particularly the Centre for Bacterial Cell Biology, which brings together a world-class group of scientists researching bacterial physiology and the host response to bacterial infections. A major focus of this research involves:

  • Exploring alternative targets for antibiotic development
  • Understanding how antibiotics attack bacterial cells
  • Investigating how bacteria overcome such an attack

Tonight (March 11th 2013), work from the group of Kenn Gerdes and Etienne Maisonneuve, a post-doc in his group, will be featured on the BBC programme “Bang Goes the Theory” in an episode about Antibiotics.

Kenn and Etienne’s research focuses on persister cells, bacterial cells that can tolerate and survive attack by antibiotics.  Importantly, ALL bacteria analysed so far generate “persister cells” and understanding this is key to understanding how bacteria avoid antibiotic attack. “Bang Goes the Theory” will show a movie showing how these persister cells are identified in a bacterial population.

Penicillin inhibits synthesis of the bacterial cell wall, causing the cell to explode (or ‘lyse’) due to the high pressure inside the cell.  This is why penicillin and similar drugs are very effective in curing infections caused by penicillin-sensitive bacteria. In the movie, see how the cells suddenly explode when penicillin is added but notice how one cell, the persister cells (darker cells not exploding on the left panel) are surviving.

These persister cells evade killing by antibiotics because they grow extremely slowly. Persisters are proposed to be one explanation for infection relapses or chronic infections so Kenn and Ethienne’s work is extremely important for understanding how we should use antibiotics.

Microfluidic chamber used to make the movie

To do this work, Etienne used state-of-the-art technology – microfluidics – to follow the growth of individual bacterial cells under a microscope. These devices are smaller than a penny coin and the chambers where the bacteria are grown can be less than 1 mm across. This technique allows us to grow bacteria in one condition but, at a flip of a switch, change it and watch the response, as seen in the movie.

Year 9 student working on one of CBCB's microscopes


CBCB academics have used the ability to explode Escherichia coli to explore the what, when and how of antibiotics with Year 9 school students as part of the University engagement program Leading Edge.

With these students, we have developed a protocol to allow them to observe E. coli in the act of exploding after adding penicillin.

Exploding E. coli. Taken by Seaton Burn Community College Year 9 students

Persistence is not Resistance: It is important to understand the difference between these two terms. Antibiotic resistant and sensitive bacteria are able to generate persister cells, that are not effected by antibiotic attack. Antibiotic Resistance is a trait acquired by the whole population.

The Scientific Specifics: Over the last few years, several scientific breakthroughs made by the Gerdes group have, for the first time, given insight into how bacteria control the switch to slow growth and persistence. Persister cells can survive penicillin because the bacteria hibernate for a period, during which they don’t synthesize their cell wall.  They can then “wake up” when the antibiotic treatment is over, causing a new infection. In young and healthy people this is usually not a problem, because the rare non-growing bacteria are removed by the immune system. However, elderly individuals or those with a weakened immune system, it is often not efficient enough to permit clearance of the rare bacteria that survive the treatment, allowing the infection to “break out”.

The Gerdes group has shown that a certain class of gene that inhibits cell growth are turned on in one cell per 10,000. These discoveries open avenues to generate novel antibiotics and treatment regimes in the future. However, before that, their group is investigating if similar mechanisms allow pathogenic bacteria, such as Mycobacterium tuberculosis, to evade killing by antibiotics.


Institute of Cell and Molecular Biosciences
The Centre For Bacterial Cell Biology
Professor Kenn Gerdes
Bang Goes the Theory
Leading Edge

An academic viewpoint on social media portals


We are, as a society, becoming inundated with comments that fall in to categories such as “did you see X on Facebook” or “Have you had a sneaky peek at that viral video?” and news articles such as this one. Here what I would like to do is pass on some of my own impressions and experiences of the benefits of using social media, focusing on Twitter and LinkedIN.


Yes, simply said, the impact science can make through such outlets presents a perfect opportunity with the drive to bring our research to the general public. Social media allows us all to interact with other scientists but, once you get going, the general public too, as we discussed here.


Technically, you do not need an account to read what’s going on; you also do not need a smartphone, any steam kettle of a PC or MAC will do.

I am in no way advocating that you join up. Have a quiet trawl through what science is on there, and maybe like me, you will make the leap! Discussing science in this format makes you think about what you say.

Being able to have a conduit that will generally be viewed by people interested in science but also has the opportunity to be picked up by a wider audience is what we are being asked to do in science. The amount of work needed to be a scientist on Twitter but not become an addict is, in my opinion, well worth it.

A good starting point is to read some of the blogs and transcripts from a fantastic episode that ran under #overlyhonestmethods during the first half of Jan 2013:

Nature.com has a number of active twitter accounts. Nature Reviews Microbiology (@NatRevMicro) regularly generates lists of papers of interest.

Microbiology Twitter Journal Club (#microtwjc). This is an organised twitter-based chat on microbiology every two weeks where a chosen paper is discussed. Recently, Microtwjc succeeded in gaining a response to one discussion by the authors of the paper – This is a form of public engagement exploiting social media portals and the group in question got free advertisement for their work!


I will openly admit I can not remember actually joining up to this portal. I, like many of us, continually get emails asking me to accept someone’s invite to their community. Recently, my ex-PhD student started looking for a more secure opportunity of employment. He and a number of others in the same position were given advice to maintain their LinkedIN profile. Exploit it as a professional digital CV, use its features to the maximum and, importantly, generate your own “linked in community” of people you know in science that can support your claims. This includes knowing how to pour gels, purify proteins and use seriously kick-ass microscopes or any other piece of kit we have access to! He got his current position due to his profile fitting a match during an employment consultation search.

This experience has given me a chance to see what its uses are. This means that my LinkedIN profile has gone from being an annoyance to something that is there to support my students and post-docs (if I ever have any again!) when they are actively looking for employment. Its not there for my own gain, its there so that they can state who trained/taught them and if someone wishes to, they can view my profile and look at my own career history.

My social media timeline:

I have been on Facebook since 2009. I joined Twitter in March 2012 and this will be my second date with blogging.

I joined Facebook for a very specific reason. I had the amazing opportunity through a joint Royal Society and Daiwa foundation International Project Grant to visit my Japanese collaborators for 3 months. It was agreed that we would keep our family up to date with our antics by exploiting Facebook’s method of publishing photos.

I joined Twitter through a friend posting tweets to Facebook: these included what was floating their boat on new papers, commenting on science articles in the press and generally having science-based discussions with other scientists. I made a decision from day one Twitter would be for science (hahaha!). What do I have now? Well, I do focus on Science and I follow a good group of science communicators across the UK and US. I also seem to be following many of the real ale bars of Newcastle upon Tyne!

Image Sources: Here and Here