You might remember zinc best as zinc oxide, the thick white cream slathered on babies with nappy rash and used for burns, cuts and scrapes. It’s a good barrier cream to protect the skin.
But internally, zinc serves useful functions too – one of which is helping the production of healthy sperm. That’s because it promotes cell growth and multiplication, and supports the immune system.
Now, exciting research from Warwick University is pointing the way to its use against superbugs – bacteria that are resistant to antibiotics.
Acinetobacter baumannii (AB) is one of those and it can cause infections in the blood, urinary tract and lungs, or in wounds in other parts of the body.
It’s a particular problem in hospitals. Some patients can carry AB without any symptoms while in others the bacterium causes serious illness, and can even lead to death.
Unfortunately, many AB infections are resistant to antibiotics, making them difficult to treat.
But the Warwick research has found that zinc plays a key role in how AB cells form their shape and identifies this process as a new target for overcoming resistant infections.
Dr Carmina Micelli, who collaborated with researchers from Northwestern and Tufts Universities in the US, noticed the importance of zinc when she was studying a group of enzymes known as penicillin-binding proteins (PBPs), which control the shape of AB bacteria cells.
The story of her sleuthing is as exciting as a whodunnit.
She said: “I was using X-ray crystallography to study PBPs when I noticed a single zinc ion in a particular structural part of PBP2. I knew this hadn’t been discovered before.
“When zinc was removed, the stability of PBP2 was reduced and resulted in loss of its function. This caused AB to change shape, in the same way that antibiotics would.”
Dr Micelli went on to show such cells were also more vulnerable to existing penicillin-type drugs.
“This study shows that AB cell shape appears to require zinc to function.
“Maintenance of cell shape is vitally important for bacterial life and the enzyme PBP2 is at the heart of this process,” added Dr Micelli.
Professor David Roper at Warwick University, said: “There are several non-antibiotic drugs that can be used to trap zinc already under analysis for use in medicine.
“Combining these drugs with certain penicillin-based compounds could provide a new way to deal with AB infections and combat highly resistant forms of this bacteria.”
Professor Roper added that this research could be used for C. diff, another resistant hospital bug.
Who’d have thought zinc would be a weapon against resistant bacteria?