Navigation Links
Bacteria hijack plentiful iron supply source to flourish

In an era of increasing concern about the prevalence of antibiotic-resistant illness, Case Western Reserve researchers have identified a promising new pathway to disabling disease: blocking bacteria's access to iron in the body.

The scientists showed how bacterial siderophore, a small molecule, captures iron from two abundant supply sources to fan bacterial growth as well as how the body launches a chemical counterassault against this infection process. Their findings appear in a recent edition of The Journal of Experimental Medicine.

"Bacterial siderophore will be an important target for therapeutics one day because it can be modified to prevent bacteria from acquiring iron, but at the same time, it's possible to preserve host access to iron," said senior author Laxminarayana Devireddy, DVM, PhD, assistant professor of pathology, Case Comprehensive Cancer Center.

Investigators knew from the outset that bacterial siderophore captures iron from the host mammal and transforms it so that bacteria can absorb and metabolize the mineral. In this investigation, Devireddy and his colleagues discovered that human mitochondria, which very closely resemble bacteria, possess their own iron-acquisition machinery mitochondrial siderophore. Mammalian mitochondria are membrane-encased subunits within cells that generate most of the cell's energy, and like their bacteria counterparts, mammalian mitochondria have their own siderophore mechanism that seeks out, captures and delivers iron for utilization.

At the test tube level, investigators found that bacteria can feed on iron supplied by bacterial siderophore and mitochondrial siderophore. From this glut of iron, bacteria proliferate and make the host mammal very ill with an infection.

"It's like bacteria can use their own iron-capture machinery or the host's. It just doesn't matter," Devireddy said. "They are very good at utilizing siderophore from both bacterial and mammalian siderophore sources. That means that bacteria get the most iron."

Case Western Reserve researchers also demonstrated that the absence of mitochondrial siderophore in a mammal can enhance its ability to resist infection. When investigators exposed mice deficient for mitochondrial siderophore to systemic infection by E. coli, the animals resisted infection. The reason? E. coli bacteria had less iron to access from mitochondrial siderophore-deficient mice.

Additionally, mammals are not entirely defenseless from a bacteria raid on mitochondrial siderophore iron supplies. In another phase of their investigation, scientists found that normal mice secrete the protein lipocalin 24p3, which isolates bacterial siderophore and suppresses synthesis of mammalian siderophore.

"The action of lipocalin significantly reduced the mortality of the mice from the E. coli infection, and some mice actually recovered," Devireddy said. "That kind of delay in bacterial proliferation gave the immune system time to identify and then neutralize the microbe."

These findings highlight the potential of developing effective therapeutics to reverse bacterial infection.

"Any approach that would suppress either bacterial or mitochondrial siderophore and activate lipocalin-2 would likely slow infection, allowing the host's immune system to respond," Devireddy said. "Such novel approaches would also provide a much-needed alternative to treat those infections that have become antibiotics resistant."


Contact: Jeannette Spalding
Case Western Reserve University

Related biology news :

1. Leading evolutionary scientist to discuss how genome of bacteria has evolved
2. Study by UC Santa Barbara researchers suggests that bacteria communicate by touch
3. Team discovers how bacteria resist a Trojan horse antibiotic
4. From scourge to saint: E. coli bacteria becomes a factory - to make cheaper, faster pharmaceuticals
5. Bacterial shock to recapture essential phosphate
6. Disarming disease-causing bacteria
7. Study shows unified process of evolution in bacteria and sexual eukaryotes
8. Invisible helpers: How probiotic bacteria protect against inflammatory bowel diseases
9. Researchers develop rapid test strips for bacterial contamination in swimming water
10. Bacteria discovery could lead to antibiotics alternatives
11. Agricultural bacteria: Blowing in the wind
Post Your Comments:
(Date:6/27/2016)... Research and Markets has announced the addition of the ... offering. The report forecasts the ... at a CAGR of 12.28% during the period 2016-2020. ... analysis with inputs from industry experts. The report covers the market ... also includes a discussion of the key vendors operating in this ...
(Date:6/22/2016)... June 22, 2016  The American College of Medical Genetics ... Executive Magazine as one of the fastest-growing trade shows ... at the Bellagio in Las Vegas . ... percentage of growth in each of the following categories: net ... and number of attendees. The 2015 ACMG Annual Meeting was ...
(Date:6/22/2016)... , June 22, 2016   ... management and verification solutions, has partnered with ... software solutions for Visitor Management, Self-Service Kiosks ... provides products that add functional enhancements to ... provides corporations and venues with an automated ...
Breaking Biology News(10 mins):
(Date:6/24/2016)... , ... June 24, 2016 , ... While the majority ... as the Cary 5000 and the 6000i models are higher end machines that use ... height of the spectrophotometer’s light beam from the bottom of the cuvette holder. ...
(Date:6/23/2016)... , ... June 23, 2016 , ... ... pleased to announce the launch of their brand, UP4™ Probiotics, into Target stores ... 35 years, is proud to add Target to its list of well-respected retailers. ...
(Date:6/23/2016)... 23, 2016 A person commits a crime, and ... to track the criminal down. An outbreak of ... Drug Administration (FDA) uses DNA evidence to track down the ... Sound far-fetched? It,s not. The FDA has increasingly used a ... of foodborne illnesses. Put as simply as possible, whole genome ...
(Date:6/23/2016)... Cancer Foundation (PCF) is pleased to announce 24 new Young Investigator (YI) ... of the Class of 2016 were selected from a pool of 128 applicants ... the Class of 2016 PCF Young Investigators ... ... ...
Breaking Biology Technology: