PRIZE. Astrid von Mentzer, a postdoctoral researcher in the Department of Medical Microbiology and Immunology, was recently named the winner of the photo contest arranged by National Microscopy Infrastructure (NMI). Her winning image shows an ETEC bacterium expressing a new type of hair-like proteins that she discovered.
“It’s always great when one’s work attracts attention and that it was a picture of enterotoxin-forming E. coli (ETEC) that won the contest. Few people know about ETEC in spite of the fact that it’s one of the most common pathogenic E. coli that causes diarrhea, especially among children and adults in countries with a shortage of clean water and poor sanitary conditions, but also for tourists traveling to affected areas,” says Astrid von Mentzer.
She defended her thesis two years ago with a dissertation on the whole genome sequencing of ETEC. She created the image for the cover of her dissertation.
“When I read that the contest was to link science and art, I thought it qualified. The timing of the contest also was suitable because the image makes me think of summer – hence the name ‘Coltsfoot Explosion.’”
In her dissertation Astrid identified a new colonization factor, which is hair-like proteins that sit on the surface of the bacterium and are used to attach to the gut epithelium.
“This was one of the first images showing that the identified gene cluster was actually functional and resulted in the expression of this new colonization factor, which I chose to christen CS30. Screening of our strain collection consisting of more than 4,000 ETEC strains collected over a 30-year period and from several countries has shown that CS30 is a relatively common colonization factor.
By using whole genome sequencing, Astrid von Mentzer showed in her dissertation that there are specific clones of ETEC that have spread across the world during the past 200 years and that these are still circulating and causing diarrhea. Between 20 and 50 percent of all clinical ETEC strains lack a known colonization factor, which is needed to colonize the intestinal mucosa. In her dissertation Astrid analyzed a number of such ETEC strains with bioinformatic methods, which resulted in the identification and characterization of CS30, appearing as the hair-like structures in the image.
Also a big problem for livestock
As a postdoc, she is investigating how ETEC has adapted to various hosts. ETEC causes diarrhea not only in humans; it’s also a major problem for livestock, especially piglets and calves.
“CS30 is related to the surface proteins of pig-associated ETEC strains, and we have preliminary data indicating that host-associated virulence factors, such as CS30, and antibiotic-resistant genes can be spread between ETEC strains that infect a specific host. This could pose problems because the spread of antibiotic resistance could also come from ETEC strains previously considered host-specific,” says Astrid.
The runner-up in the contest, Jasmine Chebli, also is active at Sahlgrenska Academy. Her image shows a zebra fish embryo and appeared in the contest under the name “Scientists Under the Sea”. Both her and Astrid’s images were taken at the CCI Core Facility at Medicinareberget.
TEXT: ELIN LINDSTRÖM CLAESSEN