The effect of a common antibiotic (amoxicillin with clavulanate) on the microbiome of tonsil tissue in children with recurrent tonsillitis

This randomised, investigator-blinded, prospective study will be conducted at Gillies and Starship Hospitals in Auckland, New Zealand. The study will only take place one the appropriate ethics and institutional approvals have been obtained. All patients will give written informed consent wherever possible, or their legal guardian will provide assent before entering the study. The primary objectives of the study are to compare the microbiome of palatine tonsil tissue in two groups of patients with recurrent tonsillitis. One group of 30 patients will be prescribed a 7-day course of Amoxicillin and Clavulanic acid immediately prior to surgery. The other group of 30 patients will receive no antibiotic. The dose of Amoxicillin and Clavulanic acid (Augmentin) will be prescribed according to Medsafe, New Zealand guidelines as follows: Children 3-9 months: 1.25mL of AUGMENTIN Syrup 125 three times a day. Children 9 months - 2 years: 2.5mL of AUGMENTIN Syrup 125 three times a day. Children 2-6 years: 5mL of AUGMENTIN Syrup 125 three times a day. Children 7-12 years: 5mL of AUGMENTIN Syrup 250 three times daily. Adults and Children 40kg and over: 1 AUGMENTIN 500 Tablet twice daily. Prior to tissue being excised by the surgeon, a surface swab will be taken from the right and left palatine tonsils.16s sequencing will be performed on tonsil swab specimens to determine the microbiome. This information will be supplemented with live/dead bacterial staining from the surface of these tissues as one of the limitations of 16s is that we are unable to determine which bacteria are alive or dead. Without live/dead staining we would not be able to determine which bacteria had been killed by the antibiotic. A computerised randomisation schedule will be used to assign eligible patients to the antibiotic/no antibiotic group. Study medications will be provided by an independent individual (not a study investigator) of the hospital pharmacy, whereas results from microbiome analysis will be evaluated by the study investigators. An independent investigator (research nurse) will contact the patients on the day prior to surgery to ensure compliance with medication. Should the patient have not been compliant with medication then he/she will be excluded from the study. Compliance will be monitored by the use of dose cards on which patients record each dose of the study medication taken. Information regarding adverse events will be obtained by the research nurse upon conversation with the patient prior to surgery. Patients will be advised to stop taking the medication should they notice any adverse effects. They will be provided with the contact details of the research nurse and coordinating investigator. They will be encouraged to contact either party should they have any concerns. All adverse events will be recorded on a medical-event form. The investigator will classify events as serious or non-serious according to the guidelines of the International Conference on Harmonisation of Technical Requirements of Pharmaceuticals for Human Use and will judge whether the event is related or unrelated to the study medication.