The detection of bacteria and bacterial biofilms in punctal plug holes.

摘要

PURPOSE: An investigation into bacterial biofilm formation on and in punctal plugs. METHODS: The study involved 21 patients with severe dry eye whose puncta were occluded by the use of punctal plugs. Of these, 15 had Sjogren's syndrome, 3 had non-Sjogren's syndrome, 2 had Stevens-Johnson syndrome, and 1 had graft-versus-host disease. From 17 of the 21 subjects, 18 samples of material were extracted from the holes of the punctal plugs (16 unilateral and 1 bilateral) and were subjected to enrichment culture. Nineteen punctal plugs were removed and processed for electron microscopy: 15 by scanning electron microscopy, and 4 by transmission electron microscopy. RESULTS: Positive cultures were found in 8 of 18 (44%) samples of the material extracted from the holes of punctal plugs. In six of these eight cases (75%) the cultured bacterial species was Staphylococcus epidermidis, whereas in the other two cases (25%) it was S. aureus. In 8 of the 15 punctal plugs examined by scanning electron microscopy and in the material extracted from 1 plug that was examined by transmission electron microscopy, there was clear evidence of bacterial colonization. CONCLUSION: Careful observation of patients with punctal plugs is important. If material accumulates in or on a punctal plug, it may contain bacteria and may form a bacterial biofilm. In these cases, replacement of the plug, clearing of the hole, or an alternative treatment should be considered.