Philadelphia, February 10, 2026 – A new study led by researchers at Children's Hospital of Philadelphia (CHOP) and the University of Pennsylvania School of Medicine (Penn Medicine) has identified which strains of Staphylococcus aureus – commonly known as staph – are commonly transmitted in neonatal intensive care units and which specific strains are most likely to cause invasive and serious infections.
The findings, published today in Nature Communications , offer a critical blueprint for precision surveillance of staph in the NICU and provide an important foundation for reducing infections in vulnerable newborns.
Staphylococcus aureus is a bacterium often found on the skin and in the noses of healthy people. While usually harmless, certain strains can cause anything from mild skin infections to more serious bloodstream infections and pneumonia. A recent study found that one in four healthcare-acquired infections in very preterm U.S. infants were due to staph.
As part of bi-monthly surveillance sampling at CHOP led by co-lead author Lakshmi Srinivasan, MD , an attending physician in the Division of Neonatology and the Pediatric Sepsis Program, nurses routinely swab the noses of babies in the neonatal intensive care unit (NICU) to test for the presence of these bacteria. However, there are currently no standard approaches for NICU surveillance of staph, and there is little evidence for when to begin or stop surveillance, how frequently to test, and which patients to closely monitor.
"Staph is a critical human pathogen and a major cause of severe infection in our highest-risk infants," said co-senior study author Joseph Zackular, PhD , a researcher in the Department of Pathology and Laboratory Medicine and Co-Director of the Center for Microbial Medicine at CHOP. "In this study, we brought together basic researchers, clinicians, and computational biologists in a highly collaborative effort to address a major challenge in pediatric health."
Utilizing expertise in CHOP's NICU, the Center for Microbial Medicine, the Infectious Disease Diagnostics Laboratory , and the Microbiome Sequencing Center , researchers performed precision surveillance of invasive infections of staph in high-risk infants with the goal of identifying new strategies for prevention and control. Over three years, whole-genome sequencing showed that shared spaces and physical proximity were major drivers of staph transmission. Stable colonization by two types of staph, MSSA and MRSA, occurred across all areas within the NICU, and an analysis of more than 1,000 staph genomes revealed strain-specific persistence and colonization patterns, with MSSA causing more colonization and invasive disease than MRSA.
"Our study demonstrated that certain strains of staph pose significantly greater risk by being more transmissible and potentially more invasive, suggesting that a more effective prevention strategy might isolate and target the strains that cause the most infections," said co-senior study author Ahmed M. Moustafa, BPharm, PhD , a researcher in the Division of Gastroenterology, Hepatology and Nutrition and Co-Director of the Center for Microbial Medicine at CHOP and the Sequencing Core Director of the CHOP Microbiome Center.
"This study provides a path forward for real-time interventions and improved surveillance that we hope can be implemented in NICUs around the country and improve the health and safety of preterm infants," said co-senior study author Paul J. Planet, MD, PhD , an attending physician in the Division of Infectious Diseases at Children's Hospital of Philadelphia and Co-Director of the Center for Microbial Medicine at CHOP.
This study was supported by the Center for Microbial Medicine at the Children's Hospital of Philadelphia and National Institutes of Health grant 1R01AI185544.
She et al, "Rapid dissemination of Staphylococcus aureus in the neonatal intensive care unit is associated with invasive infection." Nat Commun. Online February 9, 2026. DOI: 10.1038/s41467-026-69074-z
About Children's Hospital of Philadelphia:
A non-profit, charitable organization, Children's Hospital of Philadelphia was founded in 1855 as the nation's first pediatric hospital. Through its long-standing commitment to providing exceptional patient care, training new generations of pediatric healthcare professionals, and pioneering major research initiatives, the hospital has fostered many discoveries that have benefited children worldwide. Its pediatric research program is among the largest in the country. The institution has a well-established history of providing advanced pediatric care close to home through its CHOP Care Network , which includes more than 50 primary care practices, specialty care and surgical centers, urgent care centers, and community hospital alliances throughout Pennsylvania and New Jersey. CHOP also operates the Middleman Family Pavilion and its dedicated pediatric emergency department in King of Prussia, the Behavioral Health and Crisis Center (including a 24/7 Crisis Response Center) and the Center for Advanced Behavioral Healthcare
