My BRAVO! Summer in the UK: Pathogens, Pride, and Playing Ping-Pong
During a day trip to London, one of my favorite historical sites that I visited was the Broad Street Pump, a landmark commemorating the birth of epidemiology. In 1854, English scientist John Snow used case mapping and interviews to trace a cholera outbreak to bacteria-contaminated water from the pump. His work led city officials to remove the pump’s handle, effectively stopping the outbreak. Nearly two centuries later, his methods remain a cornerstone of the field of epidemiology and infectious disease research. A replica of the handle-less pump now stands on Broad Street, honoring Snow's pioneering work.
This past summer, I was immensely grateful to have been selected for the BRAVO! program. As a lover of British television and a Microbiology major, it seemed that the BRAVO! program had enabled me to quite literally live and breathe a combination of two of my greatest passions: Pathogens and England. This is my account of the experience.
I spent the majority of my time in the UK at the University of Birmingham, working in the van Schaik research group. My project was to study the bacterial species Staphylococcus haemolyticus. S. haemolyticus normally lives on the skin of healthy people, but, under certain circumstances, such as contamination during implant surgery, immune-compromise, or preterm infant hospitalization, the bacterium can cause a variety of serious diseases, including fatal sepsis. Worse yet, S. haemolyticus can become highly antibiotic-resistant, and is also able to transfer its antibiotic-resistance genes to other related bacteria such as MRSA, complicating treatment efforts. Despite the rising incidence of disease caused by this pathogen, scientists don’t yet know much about how the bacterium persists in the environment, nor how human infections involving S. haemolyticus develop and spread.
My project was focused on learning how to make targeted mutations in the genome of our lab’s strains of this bacterium. Mutant-making is one of the primary ways scientists learn about how bacteria spread from person to person and cause disease; thus learning how to mutate S. haemolyticus would give researchers the opportunity to understand this pathogen with much greater depth. However, as bacteria go, S. haemolyticus has somewhat of a reputation for being difficult to mutate. Thus began the series of procedural trial-and-error that constituted the bulk of my project– here is an abridged account of what I did:
Attempt 1: Borrowing a protocol developed for Staphylococcus aureus, a related species of bacteria, I grew my S. haemolyticus cells, washed them in water, then glycerol, and froze them. This was to make their membranes more permeable, priming them for what was to come. The next day, I thawed my frozen cells, and used a machine called an Electroporator, which uses electric shock to insert pieces of DNA, known as plasmids, through the bacterial membranes. These pieces of DNA contain instructions to make edits to the bacterial genome. After ‘electroporation’, my cells were put on agar plates to determine the success of the trial. Result: unsuccessful.
My first week of life in the UK was everything I could’ve wished for. The architecture was beautiful, it was May and yet nowhere near the triple digits; lichens and daisies and bright green grass grew everywhere. I felt welcomed by my new lab, and I felt excited about my project. My first weekend, I marched Birmingham’s 2024 Pride Parade representing the University of Birmingham’s Institute of Microbiology and Infection.
Attempt 2: I switched protocols, this time using one my PhD mentor uses for her experiments on the bacterium Enterococcus faecium. I grew my S. haemolyticus cells, washed them in slightly different glycerol-water solutions according to the instructions in the protocol, and froze them. Using a different ratio of DNA to cells, I pushed my tube into the Electroporator and awaited my results. Result: unsuccessful.
In the weeks following, I made some headway in understanding how the lab was set up, and what basic lab practices were different between my lab in the US and my lab in the UK (their health and safety regulations in particular took me by surprise). I also started to get to know my lab and office-mates a bit better. On weekdays, we would have lunch together. On Friday evenings, we’d play ping-pong and then head to the pub on campus. I learned about their propensity for Pokemon Go, Magic the Gathering, jogging, English cider, and the New York Times puzzle game ‘Connections.’ One of my labmates started delivering me daily updates on team USA as they played in the 2024 Cricket World Cup. Another introduced me to her bouldering gym.
Willem, My PI, found a paper with yet another new protocol. This one held promise; using this procedure, the authors successfully got DNA into strains of S. haemolyticus– not just a related species of bacteria. Once more, I grew my cells, and washed them this time in highly concentrated salt (instead of glycerol), then pure water, and froze them. I then performed a new procedure to increase DNA concentration. Using my new cells and new DNA, I attempted my electroporation. Result: The electroporator killed my cells.
As I came to find out, the city of Birmingham is full of curiosities. Firstly, the university campus has a clock tower affectionately named Old Joe (right), which earns its notoriety as the tallest free-standing clock tower in the world. Peregrine falcons live inside the bit that houses the bell, and occasionally swoop down to catch their prey. Walking into the train station in the heart of the city, one is met by an enormous metal bull with a moving tail and head. The Birmingham City Library contains a balcony secret garden, and the interior is adorned with fairy lights. Birmingham was also the birthplace of Cadbury Chocolate, and now is home to ‘Cadbury World,’ a visitor attraction dedicated to sharing the history of the company and the joy of chocolate.
We figured that my cells died in the electroporator the last time due to the high salt concentration in the tube leftover from the high-concentration salt wash. This time, I increased the number of water washes post-salt wash, to cleanse the tube of all residual salt. Then came the usual freeze, thaw, adding DNA, and electroporation. Result: No cell death, but nonetheless unsuccessful.
Known for being a green city, Birmingham contains some of the most breathtaking parks and gardens I’d ever visited. Adjacent to the university is Winterbourne Gardens, which contains greenhouses full of very unique plants (including several carnivorous ones) and, behind them, a labyrinth of wooded trails and a lake. To the north is Sutton Park, a very large forested area of land punctuated by clearings of grass, wild horses, and a smattering of abandoned lean-to shelters. Canals run through various parts of the city, lined with vines, nettles, and brambles bearing ripe wild blackberries in late summer.
To gain more insight into the obstacles we were facing in S. haemolyticus electroporation, we spoke to a professor in the building known for her research on bacteria in the genus Staphylococcus, the amazing Prof. Geoghegan. She gave us a new procedure and some experimental tips, one of which included using an easier-to-electroporate member of the Staphylococcus genus as a positive control for DNA reception. This was to ensure that our unsuccessful streak was to do with our finicky strain, and not human or equipment error. Using her new insights and procedure, I tried again. Result: Positive control successful! (Target strain unsuccessful.)
In addition to my exploration of Birmingham, I also took some time to explore other parts of the UK– I went to Cambridge and took a walking tour themed around the life and work of Douglas Adams, the author of the The Hitchhiker’s Guide to the Galaxy book series (one of my favorites); I toured a microbiology lab in Oxford– the one where penicillin was first purified for medical use; saw Stratford-Upon-Avon, the place where Shakespeare lived and produced his famous works; and experienced as much of London as I could manage (there is never a shortage of things to experience in London).
Through Professor Geoghegan, we were put in touch with another research group who works on S. haemolyticus and had had some success electroporating their own strains of the bacterium. They gave us their advice, which was essentially to play a game of statistical likelihoods. With the highly developed ability of S. haemolyticus to resist taking in foreign DNA, successful electroporation was somewhat a matter of chance. The solution was to make our electroporation solution as thick with cells and DNA as we could manage, increasing our odds of a one-in-a-million successful insertion of the DNA into the bacterial cell. To do so, I used a different procedure to acquire and concentrate the plasmid DNA (one which gave me higher DNA amounts). I also lengthened the time given to let the cells grow , allowing more cells to accumulate prior to washing. Electroporation performed, I put my agar plates in the incubator to grow overnight. Result: Positive control successful; Target strain remains unsuccessful.
If I was to choose one word to describe my BRAVO summer, I’d choose the word ‘full’-- full of events, full of new experiences, full of interesting people, full of trial-and-error and experimentation (both inside and outside the lab), full of opportunities and unforeseen situations and immense amounts of fun. Though my experiments did not end up working as hoped, I learned an incredible amount, not only about the unique electroporation-resistance of Staphylococcus haemolyticus, but about how to adapt to a new work setting and a new culture, how to make friends out of strangers, what the rules of cricket are (I even watched a game, pictured at right); how to rest, and how to enjoy spending time alone. The end of this trip made for one of the most difficult goodbyes I’ve ever had to make, and I am certain I will be back visiting again soon. I am deeply indebted to all those who have made this trip possible for me, and all who have made it as wonderful as it was to experience.