Key points:
- A recent study showed 58% of bloodstream infections in preemies originates from bacteria in the gut.
- In about 79% of cases, researchers found the disease-causing strain in the gut after a bloodstream infection was diagnosed.
- Scientists say responsible antibiotic use is key when treating infants with confirmed or unconfirmed bacterial infections.
In recent research, micobiomes have been linked to a variety of health issues in humans. Now, a team at Washington University School of Medicine has added another one—bloodstream infections in the littlest patients. For premature infants, bloodstream infections are a serious concern as most experience at least one episode of the life-threatening infection after 72 hours of life.
Until recently, virtually every prematurely born baby was treated with antibiotics as a preventive measure. While the antibiotics are intended to target disease-causing pathogens, this treatment also can lead to disruption of the gut microbiome in a way that could allow virulent strains of antibiotic-resistant bacteria to increase in numbers.
The most common bacteria in bloodstream infections are also commonly found to colonize the gut without initially causing disease. For their study, researchers sought to determine whether such bloodstream infections come from inside the gut or from external transmission.
Working with newborns from neonatal intensive care units at three different hospitals, researchers used whole genome sequencing on the bacterial strain causing the bloodstream infection. They then used computational profiling to track the identical strain within feces to identify the strains of bacteria that had colonized the infants’ guts prior to bloodstream infection.
In 58% of these cases, the researchers found the gut-origin hypothesis to be true, and in about 79% of cases, they found the disease-causing strain in the gut after a bloodstream infection was diagnosed.
The data also demonstrated that some of the strains of bacteria that caused bloodstream infections were shared among infants within the NICU. This indicates that even in controlled environments, there still could be microbes exchanged between infants, shared by hospital staff or transferred from NICU surfaces.
The scientists say, moving forward, responsible antibiotic use is key, meaning the drugs should only be given to infants who have confirmed bacterial infections. The study also suggests that it may be possible to develop a risk assessment tool to help physicians quantify the risk of future bloodstream infections by identifying whether disease-causing bacteria already have colonized an infant’s gut and to what degree.