Newborns carry antibiotic resistance genes within first hours of life

Antibiotic resistance genes (ARGs) – segments of DNA that help bacteria survive the effects of antibiotics – can be present in newborns within the first hours of life, according to research presented at ESCMID Global 2026.

"This finding suggests that a pattern of ARGs is already established at this stage. The neonatal gut harbours a diverse resistome, and the presence of clinically important ARGs so early in life is concerning," Dr Ftergioti added.

"Although some ARGs were expected, their high prevalence across the majority of samples was striking – particularly for clinically critical genes offering carbapenem resistance."

The study also identified associations between resistance genes and several maternal and neonatal factors. The presence of the msrA (macrolide-streptogramin resistance) gene was linked with maternal hospitalisation during pregnancy, while a higher number of resistance genes was associated with central venous catheter placement within the first 24 hours of life. Both findings likely reflect exposure to healthcare-associated microbes in hospital settings.

"Surprisingly, resuscitation shortly after birth was associated with fewer resistance genes. We would caution that this finding should be interpreted carefully, however, as it may reflect differences in early microbial exposure or other clinical factors," Dr Ftergioti noted.

Overall, the findings suggest that both maternal transmissions and early exposure to the hospital environment may contribute to the establishment of ARGs in the neonatal gut.

"While further research is needed to understand how early carriage of resistance genes affects microbiome development and infection risk, these findings highlight the importance of surveillance, infection prevention and control in neonatal care," concluded Dr Ftergioti.

Source:

European Society of Clinical Microbiology and Infectious Diseases