This figure was used as an advertisement for the seminar club event. The portrait photograph was kindly provided by Dr. Wiles. The pictures at the left are from Dr. Wiles’ SuperBugs lab showing a 96-well plate for measuring bioluminescence in bacteria and petri dishes with molds. The picture on the top right is also from her lab, showing a broth with bacteria under normal light and giving blue light in the dark, and the picture of the mice is from Andreu et al. PLoS ONE 5(5): e10777 and shows bioluminescent mycobacteria infecting mice. The background picture is from the Te Anau glowworm caves in New Zealand, taken as a screenshot from a video shown on the homepage of Dr. Wiles’ SuperBugs lab.
Summary of CMS Seminar Club presentation on Saturday, January 27, 2024
Title: Illuminating Science!
Speaker: Dr. Siouxsie Wiles, Head of the Bioluminescent Superbugs Lab, Department of Molecular Medicine & Pathology, University of Auckland, New Zealand.
On Saturday, January 27, Dr. Wiles gave a presentation at Fujita Health University. She told us about how living organisms can give light (bioluminescence) and how that can be used to investigate infectious diseases, and she also told us about science communication with the public.
Recording: For members of Fujita University, a recording of the meeting (without the discussion part) will be available at our Manabi system. Unfortunately, we cannot open the recording for a wider audience.
There were 26 participants. I only heard very positive reactions, saying that the presentation was very interesting and easy to follow. Of course, for a speaker who received multiple large awards on science communication, we shouldn’t expect anything else. I got so captivated by the story that I forgot place and time, which doesn’t often happen to me when chairing.
One of the remarkable points of Dr. Wiles’ bioluminescence work is that by using a local unique point (New Zealand molds) and lots of creativity (like using a lego-robot for aliquoting!) she is making a serious research contribution to the world-threatening problem of the increasing antibiotics resistance of hospital bacteria.
As for Dr. Wiles’ story about how she became an icon of science communication to the public, what struck me most was how natural the combination of passion (to discuss science with the public) and bravery (to not be deterred by any kinds of comments and even personal attacks) led to her current role in New Zealand and beyond as a popular and leading science communicator.
Below, I am summarizing Dr. Wiles’ seminar in some more detail.
The header image of this post is of one of the few wild 忍冬藤 (Japanese honeysuckle) that can be found around Fujita. Ornaments of this plant decorate many buildings in Fujita (see link).
The contents of the presentation
The below only describes a summary and selection of only some of the topics presented by Dr. Wiles.
What is bioluminescence and how can it be used to study infectious diseases?
Bioluminescence is the emission of light through a biochemical reaction found in some living organisms, which is a different principle from fluorescence which first requires the absorption of energy. A famous example of bioluminescence, used in many laboratories for recombinant expression, is the production of yellow-green light through the oxidation of luciferin by the enzyme luciferase, found naturally in fireflies (Fig. 1).
But there are also other bioluminescent insects, and New Zealand is famous for Glowing spiderbugs (Arachnocampa luminosa). The “glowworm” larvae of these insects can be found, amongst others, in caves (see also the above advertisement figure for Dr. Wiles’ presentation), where they use silk to make their hammocks (nests) hanging from the cave walls. Connected to these hammocks, a silk “fishing line” is loaded with glue droplets (Fig. 2) that reflect the blueish light of the insect’s abdomen, attracting and catching insects. The enzyme responsible for the blue color in glowing spiderbugs is also a kind of luciferase (31% identity to firefly luciferase) but the substrate, although also called “luciferin,” is entirely different (Watkins et al. 2018).
So, Fig. 1 + Fig. 2 are examples of the large natural variation in luciferase systems among species, and these differences can be exploited in recombinant biological systems (bio-engineering).
Figure 1. A) Oxidation of luciferin by luciferase. This figure is a modification of a figure shown by Dr. Wiles. B) A firefly (Photuris lucicrescens); photograph on Wikimedia by Emmanuelm.
Figure 2. A glowing spiderbug (an Arachnocampa luminosa larva) glowing from its tail region, with the sticky droplets on silk lines connected to its nest reflecting the light. Photograph modified from Wikimedia by Jon Sullivan.
Insects are not the only organisms that use bioluminescence, and, for example, also some marine bacteria employ it, some of them probably to promote being eaten by fish and end up in their digestive tract. These bacterial systems also use a “luciferase” but seemingly of a different molecular family than the insect luciferases (Delroisse et al. 2021), and again a different “luciferin,” sending out a blue light. This bacterial capacity for bioluminescence is encoded by an operon of several genes that can also be, by recombinant techniques, transferred to other bacteria. Fig. 3 shows the same bioluminescent bacteria in broth culture under normal light (left) and in the dark (right).
Importantly, because this luminescence requires the bacteria to be alive, the bioluminescent light becomes a perfect parameter for estimating the number of bacteria that are still alive. This is very convenient when, for example, checking the killing efficiency of new antibiotics. As an example for testing bacteria-killing agents in this manner, see Fig. 4.
Figure 3. The same bioluminescent bacteria in broth culture under normal light (left) and in the dark, releasing blue light (right). This figure was used as a slide in Dr. Wiles’ presentation.
Figure 4. By comparing bioluminescence levels in a 96 wells (shown at the right) to a scale (shown at the left), it can be seen how many bacteria are alive and, conversely, how efficient added agents were in killing them. This is a slide used by Dr. Wiles in her seminar.
Dr. Wiles and her group are also using the bioluminescent bacteria to screen for new antibiotics produced by molds (fungi) in New Zealand. The molds in this country with its special natural environment are quite unique, and they keep finding new species of molds. Fig. 5 shows how they test the bacteria-killing ability of these molds by growing them on agar in petri-dishes and then punching holes in those plaques, which they fill with bioluminescent bacteria. They found, as well known, that the growing conditions (e.g., temperature and food) are critical for whether the molds did or did not produce antibiotics (an antibiotic is a molecule that kills bacteria). They supplement this screening system by using 24 well plates where to bioluminescent bacteria, either grown on agar or in broth, they add a little peace of mold (creating a screening system similar to as for the 96 well plate shown in Fig. 4).
After having identified that a mold is toxic for bacteria, they try to find the responsible agent using a similar screening system but starting with chromatography fractions from homogenized mold and continuing from there. I will not discuss that in detail here, but I just like to show the lego-machine (!) that they built to allow the extensive collection of chromatography elution fractions necessary for such screening, thereby avoiding having to buy expensive equipment (Figure 6). This lego fraction collector was adapted from a paper by an American group (Caputo et al. 2020).
If I understood Dr. Wiles correctly, they have not found a new antibiotic yet that has already been shown to fulfill all requirements for becoming a new antibiotic in the clinic, but they found a set of promising candidates.
Figure 5. New Zealand molds tested for their killing ability of bioluminescent bacteria. After punching holes in the mold plaques grown on agar, and filling those with bioluminescent bacteria, the light intensity in the dark (picture on the right) is a measure of bacterial survival. This figure was used as a slide in Dr. Wiles’ presentation.
Figure 6. The fraction collector made of lego used by Dr. Wiles and her group. This is a slide used by Dr. Wiles in her seminar.
Science communication to the public
Dr. Wiles first became a science communicator when she won a prestigious prize in the UK, the Inaugural UK National Centre for the Replacement, Refinement & Reduction of Animals in Research (NC3Rs) 3Rs Prize, for changing experiments to reduce the suffering of laboratory animals. She got this award for her paper Wiles et al. 2006 in which she used bioluminescent pathogenic bacteria that could be monitored in the mouse intestine from outside (as exemplified for mouse lung in Fig. 7) so that the mice did not need to be sacrificed anymore to check for the development of those bacteria. She was asked by several media to explain this, and from then she realized how important it is for scientists to communicate their work with the general public.
Figure 7. Example of how internal bioluminescent bacteria, in this case mycobacteria in the lungs of mice, can be monitored by light measurement from outside the mouse. The picture is from Andreu et al. PLoS ONE 5(5): e10777.
Since then, she simply has not stopped doing this and has been intensively involved in all kinds of media and expression forms (tv, radio, blogs, podcast, art, etc.). (the following words are mine, not a summary of her presentation:) She obviously did this with great quality and fulfilling a need of the public so that in 2013 she got the Prime Minister’s Science Communication Prize and already in 2018 she was nominated as a candidate for the New Zealander of the year. When during COVID she also became a public face of explaining the pandemic to the public, in 2021 she was then really chosen as New Zealander of the year.
On this science communication aspect of her life, that she also briefly discussed during her seminar, I will not write a lot here because information can easily be retrieved from internet. I just like to highlight two of her very nice collaborations, one with her daughter in the youtube series “Siouxsie and Eve Investigate” (Fig. 8; link), which is a lot of fun and heartwarming to watch, and one with the illustrator and comic artist Toby Morris (Fig. 9) which resulted in their cartoons communicating COVID being shared by governments around the world.
Figure 8. “Siouxsie and Eve investigate” is a YouTube series in which Dr. Wiles and her daughter investigate scientific questions in every day life.
Figure 9. Dr. Wiles and the cartoonist Toby Morris as a team, and their most iconic COVID image “Flatten the Curve.” Image and words: Toby Morris and Siouxsie Wiles/The Spinoff
In her presentation to us as well as in her science communication work available online, it was also very nice to see how much fun she has in her work, and how much she likes people and enjoys talking about science with them.
It truly was very interesting, enjoyable, and inspiring to listen to her presentation.
