Somaia Abdelmegeed: Screening, failing, growing — the road to a potential antibiotic

A woman with glasses on wearing a purple hijab, white lab coat and blue latex gloves holds up a Petri dish. The dish has been swabbed and there is bacteria growing. A large microscope is in the background. — Somaia Abdelmegeed looks at a petri dish for bacterial growth. Photo courtesy of Somaia Abdelmegeed.

This piece was written in the spring of 2025 by GRAD 5144 (Communicating Science) student Somaia Abdelmegeed as part of an assignment to write a personal narrative about her research.

I was sitting in the lab, surrounded by the quiet hum of incubators, the faint scent of ethanol and agar, and the glow of blue light from my computer monitor. The only sounds were the clicking of my keyboard and the gentle whirr of the plate reader beside me. My eyes were glued to the screen, scanning a sea of data, heart pounding. It had taken days, but finally — results. Fifty-eight hits from my first screen of 1,500 compounds. After so much setup and care, it felt like a real breakthrough.

In my research, I search for new treatments against bacteria that have become resistant to one of our last-resort antibiotics. The bacteria I study are called vancomycin-resistant enterococci (VRE). To find potential treatments, I work with libraries of compounds — collections of thousands of small chemical molecules, each with different shapes and properties. You can think of them like a giant spice rack: I’m testing one “spice” at a time to see which one might stop the growth of harmful bacteria.

The screening process is like hosting thousands of auditions. Each compound is added to a tiny well, filled with bacteria, then incubated overnight. The next day, I look for the compounds that prevented the bacteria from growing. Those are called “hits."

A woman wearing a purple hijab, white lab coat and blue latex gloves is looking into a large white microscope. The microscope has test wells on the stage that the woman is looking at. — Somaia Abdelmegeed checks the test wells in which she has put bacteria and the compounds she is screening. Photo courtesy of Somaia Abdelmegeed.

After carefully analyzing the first 1,500-compound screen, I selected 20 promising candidates and sent the data to my principal investigator (PI). I was hopeful. But when he finally responded, he said:

“Great work, but none of these are promising enough to continue.”

I was crushed. Not even one.

After talking with senior lab members, I decided to go bigger. I screened a second library — 5,000 compounds. It took four intense, focused days to finish, and the results were shocking: only 13 hits. Thirteen compounds out of 5,000 showed some activity — We ordered them from a chemical company for confirmation.

I eventually received 11 out of the 13 compounds ordered and started confirming my results, but, one by one, the first five compounds failed the preliminary test. They had no activity against vancomycin-resistant enterococci, meaning no ability to kill the bacteria. That left me with just six.

These six passed the first test, so I then performed cytotoxicity tests, which are experiments designed to check whether these compounds might be harmful to normal, healthy cells. This is important because a compound that kills bacteria but also damages our own cells wouldn’t be a good treatment.

The tests involved exposing cultured kidney cells to the compounds and observing whether the cells stayed healthy or were harmed. Most of the compounds turned out to be toxic — they damaged or killed the healthy cells — so I felt discouraged again. Sometimes these toxic compounds can be chemically modified to reduce their harmful effects, making them safer for use, but that is an arduous process, not guaranteed, and would require running many rounds of testing

A week later, the last two compounds finally arrived. Remember, my goal was to find new treatments that could effectively stop vancomycin-resistant enterococci (VRE) without harming healthy human cells. I tested these compounds immediately, and, to my relief, they showed strong antibacterial activity against the bacteria. This was exciting progress, but the big question remained: Would these compounds be safe for normal cells, or would they cause toxicity like some of the others?

I ran the cytotoxicity assay, waiting anxiously for more than 24 hours. The results came in just one day before my lab meeting. One of the compounds — the most potent one — had no toxicity, even at high concentrations!

When I presented my findings, my PI was excited. He told me to order more of the compounds so that we could begin further experiments. After weeks of trial and error, I finally had something worth pursuing.

I’ve learned that science is full of setbacks, but this experience taught me that persistence is everything. If one approach doesn’t work, you try another — because the next breakthrough might be just around the corner.