In seven of the 11 infants who developed sepsis, the researchers found that bacteria in stool samples taken days to weeks before the onset of sepsis matched bacteria in the blood samples taken later, suggesting that bacteria from the gut rather than from other parts of the body quite likely caused the bloodstream infection.
"We obtained the organism from the blood and then isolated the organism from the stool and then sequenced both," Warner explained. "We could tell, because the sequences were genetically identical, that the source of that organism was the same in the blood as what was in the stool."
They also found the same microbes in the stool samples of infants whose NICU stays overlapped, suggesting that such bacteria occasionally are transmitted from infant to infant, though the bacteria don't always lead to illness.
"No one can be completely sterile; it is inevitable that bacteria will be encountered by infants in these settings," said Tarr, who is also a professor of molecular microbiology. "We do not know the origin of these bacteria in most cases. However, this study tells us that at least in a subset of infants who develop bloodstream infections, the germ that invades their blood flourishes in their gastrointestinal tracts for at least a few days before it causes sepsis.
"That's an opportunity to be on top of colonization and to be aggressive in preventing dissemination between infants in NICUs and within infants who are colonized. The concept of sepsis as gut infection offers a new strategy to prevent this serious, hospital-acquired condition independent of assiduous skin car
|Contact: Elizabethe Holland Durando|
Washington University School of Medicine