ANTIBIOTIC resistance genes (ARG) have been found in newborns within hours of birth in a study presented at ESCMID Global 2026 on 20th April.1
Researchers found segments of DNA that help bacteria survive the effects of antibiotics in newborns within the first hours of life.
Screening for ARGs
Researchers analysed meconium samples from 105 infants admitted to a neonatal intensive care unit within the first 72 hours of life between July 2024 and July 2025.
They screened samples for 56 different resistance genes associated with commonly used antibiotics.
Argyro Ftergioti, lead author, Aristotle University of Thessaloniki, Thessaloniki, Greece, said: “This is the largest study of its kind exploring the effect of hospital environment on the collection of ARGs in the neonatal gut.
“We analysed meconium samples within the first 72 hours of life to capture the earliest snapshot of microbial and genetic exposure in newborns.
“At this stage, the collection of resistance genes is mainly shaped by maternal transmission, delivery mode and very early hospital exposures.”
ARGs Present Within Hours of Life
The most common genes detected were oqxA and qnrS, which were present in 98% and 96% of samples, respectively.
Both have been associated with some commonly used antibioitcs.2
The study also identified several genes encoding beta-lactamases: enzymes that break down widely used antibiotics.3
Among these, the most prevalent were blaCTXM, blaCMY and blaSHV, at 55%, 51%, and 39%, respectively.
Genes tied to resistance to carbapenems were detected in 21% of samples and each sample contained an average of eight resistance genes.
Ftergioti continued: “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.
“Although some ARGs were expected, their high prevalence across the majority of samples was striking – particularly for clinically critical genes offering carbapenem resistance.”
Associations Between ARGs and Maternal and Neonatal Factors
The study also found the presence of msrA 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.
This likely reflects exposure to healthcare-associated microbes in hospital settings.
Infection Control in Neonatal Care
Researchers reported that findings suggest both maternal transmissions and early exposure to the hospital environment may contribute to the establishment of ARGs in the neonatal gut.
Ftergioti added: “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.”
References
1 Ftergioti A et al. Antibiotic resistance genes in meconium of newborns very early after admission to neonatal intensive care unit. 2026. Oral presentation. ESCMID Global 2026, 17-21 April, 2026.
2 Rodríguez-Villodres Á et al. Evaluation of the MDR direct flow chip kit for the detection of multiple antimicrobial resistance determinants. 2023;29(8):381-385.
3 Tooke CL et al. ß-Lactamases and ß lactamase inhibitors in the 21st century. J Mol Biol. 2019;431(18):3472-3500.
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