Seattle—It’s been a busy week for ophthalmology research and news after both the Association for Research in Vision and Ophthalmology (ARVO) annual meeting in Seattle and the American Society of Cataract and Refractive Surgery (ASCRS) annual meeting in New Orleans.
Bausch + Lomb releases preliminary 2015 results of the ARMOR study
Bausch + Lomb announced preliminary 2015 results of the Antibiotic Resistance Monitoring in Ocular Microorganisms (ARMOR) surveillance study, the only multi-center, nationwide survey of antibiotic resistance patterns specific to eye care. Researchers also presented data that examined resistance profiles of common bacterial pathogens isolated from the aqueous and vitreous humor to antibiotics routinely used in ophthalmic practice.
In the first study, ARMOR researchers reported comparisons of susceptibility rates available from surveillance in 2015 to results from 2014. At the time of the analysis, a total of 441 isolates of Staphylococcus aureus, coagulase-negative staphylococci (CoNS), Streptococcus pneumoniae, Pseudomonas aeruginosa, and Haemophilus influenza—organisms frequently implicated in bacterial eye infections—were collected from 19 sites across the United States. The isolates were then tested for susceptibility to as many as 15 antibiotics.
Similar to previous years, study authors reported that surveillance data continue to show high levels of antibiotic resistance among staphylococcal isolates, especially among methicillin-resistant (MR) strains, with many demonstrating multidrug resistance. Resistance among the staphylococci was most notable for azithromycin (54-59 percent), oxacillin/methicillin (24-45 percent), and ciprofloxacin (22-28 percent), while CoNS isolates also exhibited high levels of non-susceptibility to tobramycin (19 percent) and trimethoprim (26 percent).
In 2015, 20 percent of S. aureus isolates and 39 percent of CoNS isolates were non-susceptible to three or more drug classes, with multidrug resistance remaining prevalent among MR S. aureus (67 percent) and MRCoNS (74 percent). Isolates of S. pneumoniae remained susceptible to fluoroquinolones and chloramphenicol, while non-susceptibility to azithromycin and penicillin was 50 percent and 38 percent, respectively. Resistance among P. aeruginosa isolates continues to be low, while H. influenzae isolates were generally susceptible to all antibiotics tested.
“These latest data demonstrate that resistance of common ocular pathogens to several commonly used antibiotics continues to be a challenge,” says Penny Asbell, MD, lead ARMOR study author, professor of ophthalmology at Icahn School of Medicine at Mount Sinai, and director of the Cornea Service and Refractive Surgery Center at The Mount Sinai Hospital. “Understanding antibiotic resistance patterns is critical for the selection of effective agents to treat potentially sight-threatening ocular infections. The ARMOR data allow physicians to select agents that have proven efficacy and a broad spectrum of activity.”
In a second study, investigators examined antibiotic resistance profiles of 172 aqueous and vitreous humor isolates collected between 2009 through 2015 through the ARMOR surveillance study, including 30 S. aureus, 100 CoNS, 21 S. pneumoniae, 10 P. aeruginosa, and 11 H. influenzae. Similar to the preliminary 2015 ARMOR findings, researchers reported that antibiotic resistance was prevalent among staphylococcal isolates, particularly CoNS, with many demonstrating multidrug resistance.