Research presented at the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) Global 2026 conference in Munich last week suggests that antibiotic-resistant genes (ARGs) are present in newborns shortly after birth, reports CIDRAP News.
In a study involving 105 newborns admitted to a neonatal intensive care unit (NICU) from July 2024 to July 2025, a team led by researchers from Aristotle University of Thessaloniki in Greece performed molecular analysis on meconium, the first stool passed by newborns.
Typically passed within 24 to 48 hours of birth in healthy babies, meconium consists of a mixture of amniotic fluid, mucus, bile and cells that have been shed from the skin and intestinal tract.
Although meconium was once believed to be sterile, recent research suggests gut bacteria may pass from the mother to the foetus and baby while in the womb, during delivery and through breast feeding. In addition, infants are exposed to a number of organisms in the hospital environment after birth.
One small study found the presence of ARGs in meconium and early stool samples of one-week-old infants. Based on these findings, the researcher screened the meconium samples for 56 different ARGs.
“This is the largest study of its kind exploring the effect of hospital environment on the collection of ARGs in the neonatal gut,” said lead author Argyro Ftergioti, MD in a news release.
Overall, each sample of meconium, which were collected within the first 72 hours of life, contained a median of eight ARGs, with oqxA (98% of samples) and qnrS (96%) the most commonly detected genes. Genes carrying extended-spectrum beta-lactamase enzymes (blaCTXM and blaCMY), which can confer resistance to several antibiotic classes, were found in roughly half the samples, while genes linked to carbapenem resistance were found in 21% of samples.
Carbapenems are a last-resort antibiotic for multidrug-resistant infections.
“Although some ARGs were expected, their high prevalence across the majority of samples was striking, particularly for clinically critical genes offering carbapenem resistance,” Ftergioti said.
When they examined factors linked to the presence of ARGs in newborns, the researchers found a mix of maternal and hospital environment-related factors. For example, while some ARGs were associated with the mother being hospitalised during pregnancy, the insertion of a central venous catheter within the first 24 hours of life was associated with a fourfold risk of ARGs, a finding that suggests the newborns were exposed to ARG-carrying microbes from the hospital environment.
Impact unclear
Although it’s unclear if the presence of ARGs in the newborns heightens their risk for antibiotic-resistant infections or affects their development, the findings add to a growing body of research on how different exposures affect the infant gut microbiome, which is nearly sterile at birth but rapidly develops in the first few months of life.
A 2019 study of infants in NICUs found that preterm babies who received prolonged antibiotics to ward off infection had more potentially dangerous, drug-resistant bacteria in their gastrointestinal tract than healthy infants who received no antibiotics.
Ftergioti said the findings highlight the importance of surveillance and infection prevention and control in neonatal care.
Abstract not available
See more from MedicalBrief archives:
‘Alarming’ rise of superbugs in newborn babies – Australian study
Antibiotic resistance risking SA’s newborns’ lives