Using Microbial Genomics to Elucidate the Source of Central-line Associated Bloodstream Infections

Using Microbial Genomics to Elucidate the Source of Central-line Associated Bloodstream Infections

Central line-associated bloodstream infections (CLABSIs) are the most common healthcare-associated infection in children and are associated with morbidity and mortality. This study will attempt to identify the source of bloodstream infections (BSIs) in children with CLABSI because we hypothesize that many of the BSIs that are currently classified as CLABSIs are actually laboratory-confirmed bloodstream infections (LCBI) that may be a result of mucosal barrier injury (MBI), also known as MBI-LCBI. In order to study this, we will isolate bacteria from multiple body sites of children that have BSI in order to compare these bacteria to the strain growing in their blood using whole-genome DNA sequencing. We will also evaluate biomarkers of MBI of the respiratory tract and GI tract.

This is a prospective cohort pilot study at Boston Children's Hospital (BCH) that will explore the source of presumed CLABSI, which we believe may actually have multiple possible sources including MBI. We plan to enroll all inpatient children at BCH who meet the Centers for Disease Control and Prevention (CDC) definition of MBI-LCBI as well as children who meet the criteria for CLABSI without MBI. For all enrolled patients, we will collect samples from the oral cavity, respiratory tract, skin, and stool. These samples will be cultured in order to see if the same microbial species and strain(s) growing from the blood also grow from these other sites. Cultures will then have isolated colonies selected for whole-genome DNA sequencing to allow assessment of genomic diversity between body sites. Stool and blood samples will be tested for markers of MBI. All patient enrollment and sample collection will be done at BCH.

Inclusion Criteria:

• Hospitalized at Boston Children's Hospital
• Central venous catheter of any type including peripherally inserted central catheters (PICC) in any location.
• Laboratory-confirmed bloodstream infection (LCBI) diagnosed by a clinical blood culture growing certain Gram-negative rods

Exclusion Criteria:

• Patients with CDC-defined secondary bloodstream infections