Antibiotic Resistance Common In Infections After Ocular Surgery Interview with:

Dr-Penny Asbell

Dr. Asbell

Penny Asbell, MD
Icahn School of Medicine
Mt. Sinai, New York City. What is the background for this study?

─     Bacterial endophthalmitis is a serious, although infrequent, complication of ocular surgery, typically caused by perioperative introduction of bacterial flora from the patient’s own conjunctiva and skin.

─     Prophylactic measures such as perioperative antibiotic treatment may minimize the risk for endophthalmitis, but can be complicated by antibiotic resistant bacteria.

─     The ongoing Antibiotic Resistance Monitoring in Ocular micRoorganisms (ARMOR) study is the only nationwide antibiotic resistance surveillance program specific to ocular pathogens.

─     The purpose of this presentation is to report on the antibiotic susceptibility profiles of bacterial isolates from the vitreous and aqueous humor collected in the ARMOR study expanding upon earlier findings. What are the main findings?

─     207 presumed endophthalmitis isolates (aqueous n=69; vitreous, n=138) were collected from 35 clinical sites and included 119 coagulase-negative staphylococci (CoNS), 40 Staphylococcus aureus, 25 Streptococcus pneumoniae, 11 Haemophilus influenzae, and 12 Pseudomonas aeruginosa.

‒      Among staphylococci, 60/119 (50%) of CoNS and 15/40 (38%) of S. aureus isolates were methicillin-resistant (MR); resistance rates were high for azithromycin (53-59%) and ciprofloxacin (33-54%).

‒      MR staphylococci exhibited high resistance to azithromycin (72-93%) and ciprofloxacin (82-87%).

‒      Resistance among S. pneumoniae was highest for tetracycline (40%), oral penicillin (36%) and azithromycin (32%).

‒      Among P. aeruginosa isolates, 25% and 17% exhibited resistance to ciprofloxacin and tobramycin, respectively.

‒      No resistance was observed for H. influenzae.

─     Multidrug resistance (MDR; ≥3 drug classes) was observed in 33% of S. aureus and 46% of CoNS isolates, with MDR remaining prevalent among MR S. aureus(MRSA; 87%) and MRCoNS (72%).

‒      Besifloxacin demonstrated low MICs against all isolates, and retained low MICs against MRSA and MRCoNS isolates with MICs 16- to 128-fold lower than other fluoroquinolones What should readers take away from your report?

─     High levels of resistance among staphylococcal and pneumococcal vitreous and aqueous humor isolates were observed.

─     These findings are consistent with those for isolates from other ocular sources obtained in ARMOR and comparable to findings from endophthalmitis isolates in other studies. What recommendations do you have for future research as a result of this study?

Continued surveillance of antibiotic resistance among ocular pathogens is warranted to provide insight on changing resistance patterns and assist clinicians when selecting appropriate treatments for their patients.  Is there anything else you would like to add? Any disclosures?

─   No one antibiotic covers all potential pathogens.

— Consider antibiotic resistance when selecting antibiotic  and especially if patient is NOT responding.

Multidrug resistance is common – especially about methicillin resistant organisms.

Disclosures: COI-   consultant for B & L, but NOT related to this topic Thank you for your contribution to the community.


October 2017 AAO poster presentation of Antibiotic Resistance of Vitreous and Aqueous Humor Bacterial Isolates Collected During the ARMOR Surveillance Study”.

Note: Content is Not intended as medical advice. Please consult your health care provider regarding your specific medical condition and questions.


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Last Updated on December 14, 2017 by Marie Benz MD FAAD