A new randomized controlled trial looked at whether giving azithromycin to preterm-born infants affects antibiotic resistance. The study involved 1,108 infants, with 541 receiving azithromycin and 567 receiving a placebo. Researchers collected respiratory samples from 348 of these infants to check for genes that make bacteria resistant to macrolide antibiotics, which include azithromycin.
The main finding was that the overall prevalence of macrolide-resistant genes was similar in both groups: 63.7% in the placebo group and 63.9% in the azithromycin group. However, one specific resistance gene, called (C), was more common in the azithromycin group. Additionally, the azithromycin-resistant bacteria found were often resistant to multiple other antibiotics, involving several different resistance mechanisms.
This analysis focused on antibiotic resistance, not on whether azithromycin helped prevent chronic lung disease or improved survival. The study did not report on side effects or safety issues. The results suggest that using antibiotics judiciously in preterm infants is important, regardless of whether azithromycin is used.
For parents and doctors, this means that while azithromycin may not increase overall resistance rates, it can still promote specific resistance genes. The study highlights the need for careful antibiotic use in this vulnerable population. More research is needed to understand the full impact on clinical outcomes.
