Elimination of Conjunctival Bacterial Flora With the Use of Mupirocin Nasal Ointment

Abstract

Purpose: : It is well established that nasal carriage of gram positive organisms is a risk factor for surgical–site infections. Multiple studies have shown that nasal application of Mupirocin ointment reduces the rate of nasal gram positive organism carriage, which in turn has shown to reduce the incidence of postoperative infections in cardiothoracic, orthopedic, and other surgical patients. The objective of this study was to determine whether the use of Mupirocin ointment for perioperative eradication of nasal bacterial carriage is effective in reducing conjunctival bacterial flora.

Methods: : In this prospective blinded clinical trial, 16 eyes undergoing intraocular surgery (cataract extraction or pars plana vitrectomy) were randomized to control and study groups. All patients received a standard 5% povidone–iodine prep before the surgical procedure. In addition, patients in the study group received treatment with Mupirocin ointment twice daily in each nostril for 5 days prior to surgery. Nasal cultures were obtained in all patients (study group cultures were obtained prior to administration of Mupirocin). Conjunctival cultures were obtained in all patients before and after povidone–iodine prep.

Results: : All 16 patient nasal swabs were positive for growth. Zero of 6 eyes (0%) in the study group had positive conjunctival cultures prior to povidone–iodine prep compared with 5 of 10 eyes (50%) in the control group (p< 0.05). After povidone–iodine prep, 0 of 6 eyes (0%) in the study group and 3 of 10 eyes (30%) in the control group demonstrated positive cultures. One of the 10 (10 %) conjunctival cultures in the control group grew methicillin sensitive Staphylococcus aureus (MSSA) both before and after povidone–iodine application. That same patient grew MSSA in the nasal culture as well. In the study group 2 out of 6 (33%) patients grew Staph aureus (1 MSSA and 1 Methicillin Resistant (MRSA)) on nasal culture. However, no patient in the study group grew either MSSA or MRSA on conjunctival culture.

Conclusions: : Prophylactic use of Mupirocin ointment in the nostrils resulted in elimination of conjunctival bacterial flora with or without 5% povidone–iodine prep. The results of this small pilot series warrants further investigation in a larger trial. The use of nasal Mupirocin prior to intraocular surgery is a novel method for reducing conjunctival contamination rates and the use of this antibiotic may reduce the incidence of post–operative endophthalmitis.

Keywords: bacterial disease • conjunctiva • Staphylococcus