Human Hemoglobin May Turn Staph Aureus Bacteria Deadly, Researchers Find

Human hemoglobin, the oxygen carrying protein in red blood cells, is the most efficient fuel for Staphylococcus aureus infections, according to a study that may help explain how the bacteria homes in on certain patients with deadly consequences.

Hemoglobin also contains the iron needed for bacteria to grow and spread. Researchers led by Gleb Pishchany from Vanderbilt University Medical School’s microbiology department showed in laboratory testing how Staph aureus latches on more easily to hemoglobin from humans than other mammals to cause invasive infections.

The findings, published in the journal Cell Host & Microbe, raise the possibility that genetic variations in human hemoglobin may make some people more vulnerable to the bacteria. While one in three people have staph living in their noses, not everyone gets an infection. Those who fall ill experience everything from skin infections and food poisoning to deadly bloodstream disease and inflammation inside the heart valves.

“Human hemoglobin is a factor that impacts the host susceptibility to S. aureus,” the researchers said. The bacteria’s affinity for human hemoglobin allows it to efficiently use the protein as a source for iron that can bolster colonization and disease, the researchers concluded.

Researchers said mice that are genetically engineered to express human hemoglobin will allow them to reach findings on how staph aureus infects people. While much of the information known about staph infections comes from working with mice, they don’t perfectly model human disease, the investigators said.

“Importantly, many bacterial pathogens utilize hemoglobin as an iron source,” they said. “Therefore, human hemoglobin expressing mice may be valuable for studies into a variety of infectious diseases.”

To contact the reporter on this story: Michelle Fay Cortez in Minneapolis at mcortez@bloomberg.net