Introduction

Despite antibiotics being the primary medical treatment for recurrent tonsillitis, the impact of antibiotics on the tonsillar microbiome is not well understood.

Amoxicillin with clavulanate has broad bacterial spectrum, oral route of administration and has been shown to be effective against Streptococci and non-Streptococci in recurrent tonsillitis (RT). Further, bacterial pathogens associated with the majority of RT cases are not well known.

Aim

To determine the effect of amoxicillin with clavulanate on the composition and quantity of bacteria in the tonsils of children with recurrent tonsillitis (RT).

Patient Profile

• 60 children undergoing tonsillectomy for the indication of recurrent tonsillitis

  Method

  Study Design

• Open-label, multicenter, randomized, nonblinded clinical trial
• Patients were randomly assigned to either 7-day course of amoxicillin with clavulanate treatment immediately before and including the day of surgery or to control group (no antibiotics)
• Swabs of tonsil crypts, post the surgery, were tested by bacterial 16S rRNA gene-targeted amplicon sequencing and histological techniques

Endpoints

• Differences in tonsil microbiota composition, bacterial load, and presence of microcolonies in children with RT

Results

Efficacy

• Significantly higher relative abundances of Streptococcus (P=0.002), Haemophilus (P<0.001), Neisseria (P<0.001), and Porphyromonas (P<0.001) were found in the control group whereas higher relative abundances of Fusobacterium (P<0.001), Prevotella (P<0.001), Treponema (P<0.001), and Parvimonas (P<0.001) were detected in the antibiotic group
• Antibiotic treatment with amoxicillin with clavulanate reduced the bacterial microcolonies present in the tonsillar crypts of participants versus those in control group, as seen in the microscopic examination
• Amoxicillin with clavulanate treatment significantly reduced the Gram-positive bacterial microcolonies as compared to that in the control group (P=0.02); no difference in the number of Gram-negative microcolonies observed between the groups
• Streptococcus pyogenes was not present in any of the participant's tonsil microcolonies
• No difference seen in 30-day readmission rates between the two groups

Conclusion

Amoxicillin with clavulanate treatment immediately (a week) before tonsillectomy, significantly reduced the number of bacterial taxa commonly associated with recurrent tonsillitis, as well as the number of bacterial microcolonies observed in the tonsillar crypts of children with recurrent tonsillitis.

Microbiol Spectr. 2022; 10(6): e01239-22