Azithromycin Reduces S.aureus in Microbiome of Refractory chronic rhinosinusitis: Study

AZI-CRS was a phase 4, randomized, placebo-control, double-blinded study of 48 adults with refractory CRS. Researchers randomly assigned patients to receive either 250 mg of azithromycin or placebo three times weekly for four months. During this time, daily budesonide saline irrigations were continued. They collected sinonasal swabs by endoscopically‐assisted method before treatment initiation and at the end of it, and sent for 16S ribosomal RNA gene sequencing. They used a high‐resolution ANCHOR pipeline to infer and annotate putative species. They compared the two patient groups using DESeq2 differential abundance analysis.

Key findings of the study were:

• From initiation to the end of azithromycin treatment, researchers noted that the patients treated with azithromycin showed a significant difference in beta diversity analysis along with a significant decrease in 71 different operational taxonomic units (OTUs) of Staphylococcus aureus (false discovery rate [FDR] < 0.05) obtained from the differential abundance analysis.
• However, these changes were not observed in placebo‐treated patients.
• By the end of treatments, they found that azithromycin‐treated patients had a significant decrease in 29 different OTUs of S. aureus (FDR < 0.05) when compared to placebo.

The authors concluded, "A 4‐month course of 250 mg of azithromycin 3 times weekly in patients with refractory CRS significantly decreases S. aureus abundance in the sinonasal microbiome. Considering the pathogenic role of S. aureus in the refractory CRS population, azithromycin may constitute an additional therapeutic option to help control this disease."

For further information:

https://onlinelibrary.wiley.com/doi/10.1002/alr.22653