Prophylaxis of postoperative endophthalmitis in the setting of multi-drug resistant bacteria

Session Details

Session Title: Endophthalmitis/ Ocular Infections/ Miscellaneous

Session Date/Time: Tuesday 10/10/2017 | 08:00-10:30

Paper Time: 08:06

Venue: Room 4.6

First Author: : M.O'Rourke IRELAND

Co Author(s): :    A. Curry   N. Kealy   S. Gardner   S. Knowles   P. Barry   R. Khan     

Abstract Details

Purpose:

The exponential rise in bacterial resistance to antibiotics poses a mounting problem for clinicians. There are increasing numbers of endophthalmitis cases post cataract surgery due to multi-drug resistant (MDR) organisms. Treatment options are limited and outcomes are poor; therefore immediate pre-operative prophylaxis provides the best management solution. Currently, there are no guidelines on surgical prophylaxis in patients with MDR bacterial colonization. This study aims to assess the effectiveness of povidone-iodine (PVI) 5% and chlorhexidine 0.05% anti-sepsis on MDR bacterial isolates in the laboratory setting.

Setting:

This research took place at the microbiology laboratory at the National Maternity Hospital, Dublin which serves as microbiology laboratory for the Royal Victoria Eye and Ear Hospital (RVEEH), Dublin. The RVEEH is a tertiary referral hospital serving a population of 1 million people.

Methods:

Serial dilutions of commercially available standard organisms were exposed to PVI 5% and chlorhexidine 0.05% at time intervals of 30 seconds, 1 minute, 3 minutes and 5 minutes in triplicate. The PVI or chlorhexidine was inactivated and organisms plated on blood agar and incubated at 35°C. The number of colony forming units (CFU) was assessed after 16-20 hours. Organisms tested included the gram positive cocci: methicillin resistant Staphylococcus epidermidis (MRSE), methicillin resistant Staphylococcus aureus (MRSA), vancomycin resistant Enterococcus faecalis (VRE); the gram negative bacilli: Pseudomonas aeruginosa, carbapenem resistant (CRE) Klebsiella pneumonia, extended spectrum beta-lactamase (ESBL) Klebsiella pneumonia.

Results:

For staphylococci (MRSE and MRSA), PVI had complete effect after 3 minutes exposure. Chlorhexidine required a longer exposure time of 5 minutes for MRSA while this time point still performed sub-optimally for MRSE. PVI and chlorhexidine are effective against all gram negative bacilli tested. PVI was effective after 1 minute exposure and chlorhexidine effective after 5 minutes exposure. For enterococcus faecalis (VRE), chlorhexidine was more effective with complete inhibition only after 5 minutes exposure. PVI still allowed some growth even at 5 minutes exposure. These results were subsequently verified in 20 patients isolates for each organism tested.

Conclusions:

While endophthalmitis is a rare complication of cataract surgery, treatment options, in the setting of MDR bacteria poses a huge challenge. Patient colonization by MDR bacteria is increasing. The immediate pre-operative anti-sepsis remains key in eliminating these organisms from the ocular surface. Through analysis of MDR organisms in a laboratory setting, this study updates our knowledge on the benefits of PVI and chlorhexidine. The current ESCRS recommendation of 3 minutes exposure of PVI 5% is effective for gram negative bacilli and most gram positive cocci. However, PVI 5% is ineffective for enterococci and requires chlorhexidine exposure for 5 minutes.

Financial Disclosure:

NONE