Navigation Links
Bacteria hijack plentiful iron supply source to flourish
Date:7/9/2014

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
jeannette.spalding@case.edu
216-368-3004
Case Western Reserve University
Source:Eurekalert

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:
*Name:
*Comment:
*Email:
(Date:4/5/2017)...  The Allen Institute for Cell Science today announces ... portal and dynamic digital window into the human cell. ... application of deep learning to create predictive models of ... a growing suite of powerful tools. The Allen Cell ... publicly available resources created and shared by the Allen ...
(Date:3/30/2017)... , March 30, 2017  On April 6-7, 2017, ... the Genome hackathon at Microsoft,s headquarters in ... competition will focus on developing health and wellness apps ... Hack the Genome is the first hackathon ... The world,s largest companies in the genomics, tech and ...
(Date:3/27/2017)... , March 27, 2017  Catholic Health Services ... Management Systems Society (HIMSS) Analytics for achieving Stage ... Model sm . In addition, CHS previously earned ... hospitals using an electronic medical record (EMR). ... high level of EMR usage in an outpatient ...
Breaking Biology News(10 mins):
(Date:5/23/2017)... ... May 23, 2017 , ... ... its 20th anniversary, marking the occasion with a strong presence at Bio-IT World ... Reception and further extends an invitation to all attendees to view posters ...
(Date:5/23/2017)... ... May 22, 2017 , ... A new Technology ... Diego, California, this August will feature high-level speakers on quantum devices, graphene electronic ... Optics and Photonics, the largest multidisciplinary optical sciences meeting in North America, will ...
(Date:5/23/2017)... ... May 23, 2017 , ... Energetiq Technology, a ... a facility expansion to accommodate its rapid growth. , The renovations at the ... renovation of the existing areas. The expansion includes, a state-of-the-art engineering facility, and ...
(Date:5/23/2017)... ... ... Bacterial biofilms, surface adherent communities of bacteria that are encased in a ... and catheter infections to gum disease and the rejection of medical implants. Though ... year, there is currently a paucity of means for preventing their formation or treating ...
Breaking Biology Technology: