Shorter antibiotic course produces fewer antibiotic resistance genes, study says

A recent study determined that children diagnosed with community-acquired pneumonia (CAP) treated with five days of antibiotic therapy had fewer antibiotic resistance determinants than those who received a 10-day treatment.

The study, published in mBio, was led by Melinda Pettigrew, PhD, an epidemiologist at the Yale School of Public Health in New Haven, Conn. The study aimed to uncover how antibiotic treatment durations affect resistance genes. Pettigrew and her team of researchers analyzed data from a randomized controlled trial of children who had been diagnosed with CAP and treated with beta-lactam antibiotics. The trial analyzed involved 171 children ages six to 71 months old and found that a five-day course of beta-lactam was just as effective as a 10-day course. Pettigrew’s sub study tracked how the two treatment durations impacted antibiotic resistance genes as well as respiratory microbiota through shot gun metagenetic sequencing of participants’ throat swabs.

The study’s results revealed that children who received the five-day antibiotic treatment had fewer resistance genes associated with beta-lactam than those who received the 10-day treatment. In addition, researchers found that children prescribed the 10-day treatment had additional resistance genes related to other antibiotics.

“Antibiotics don’t just impact the pathogens that we’re trying to treat,” Pettigrew said in a statement. “They can affect the microbiota as a whole.” 

This study suggested that longer antibiotic treatments can lead to increased levels of antibiotic resistance genes. For future studies, Pettigrew said she would like to investigate the long-term clinical risks involved in antibiotic treatment effects on the microbiome.