Bacterial Antibiotic Resistance Is an Ongoing Issue1
The Antibiotic Resistance Monitoring in Ocular micRoorganisms (ARMOR) Surveillance Study found that concurrent antibiotic resistance rates were highest among methicillin-resistant isolates.1 The ARMOR study is the largest and only ongoing study that monitors resistance trends among ocular pathogens of concern.*
Methicillin-resistant Staphylococcus aureus (MRSA) isolates
showed multidrug resistance to at least 3 additional antibiotic classes.
Methicillin-resistant coagulase-negative staphylococci (MRCoNS) isolates
showed multidrug resistance to at least 3 additional antibiotic classes.
Clinical significance of these in vitro data has not been established.
*Gram-positive and Gram-negative pathogens monitored were:
Staphylococcus
aureus
Coagulase-negative staphylococci (CoNS, incl. S. epidermidis)
Streptococcus
pneumoniae
Haemophilus
influenzae
Pseudomonas
aeruginosa
Full Population Study Design: Isolates were collected from 87 ocular centers, community hospitals, and university hospitals from January 1, 2009, through December 31, 2016. A total of 4,829 ocular isolates were collected (1,695 S. aureus, 1,475 CoNS, 474 S. pneumoniae, 586 H. influenzae, and 599 P. aeruginosa) and, of these, the anatomical source (conjunctiva, cornea, aqueous humor, or vitreous humor) was known for 2,427 isolates. Minimum inhibitory concentrations (MICs) were determined for drugs from more than 10 antibiotic classes, and isolates were classified as susceptible or resistant based on available systemic breakpoints.1,3
The pediatric subgroup† (≤17 years of age) in the ARMOR study included 995 conjunctival isolates collected from 67 sites over 8 years.2
- The majority of H. influenzae, S. aureus, CoNS and S. pneumoniae isolates were obtained from pediatric patients ≤3 years of age
- About half of P. aeruginosa isolates were obtained from adolescent patients 11–17 years of age
†Safety and effectiveness in infants below one year of age have not been established
Antibiotic Resistance Is a Nationwide Concern3
From numerous samples of pathogens provided from the US, investigators evaluated resistance rates across 4 national regions
Mean percentage resistance rates shown for each pathogen across 4 regions.3
WEST
Staphylococcus aureus ... 16.8%
MRSA ... 24.4%
CoNS ... 26.0%
MRCoNS ... 44.1%
Streptococcus pneumoniae ... 7.6%
Haemophilus influenzae ... 0.3%
Pseudomonas aeruginosa ... 2.9%
MIDWEST
Staphylococcus aureus ... 23.4%
MRSA ... 40.1%
CoNS ... 27.5%
MRCoNS ... 53.8%
Streptococcus pneumoniae ... 14.5%
Haemophilus influenzae ... 0.8%
Pseudomonas aeruginosa ... 8.5%
SOUTH
Staphylococcus aureus ... 28.1%
MRSA ... 48.5%
CoNS ... 29.6%
MRCoNS ... 51.1%
Streptococcus pneumoniae ... 11.9%
Haemophilus influenzae ... 0.0%
Pseudomonas aeruginosa ... 3.6%
NORTHEAST
Staphylococcus aureus ... 23.0%
MRSA ... 36.0%
CoNS ... 27.0%
MRCoNS ... 44.3%
Streptococcus pneumoniae ... 9.9%
Haemophilus influenzae ... 0.6%
Pseudomonas aeruginosa ... 5.4%
P values for the distribution of pathogens listed above grouped by geographical region: P<0.001 for S. aureus and MRSA, P>0.05 for CoNS, P<0.006 for MRCoNS, P<0.001 for S. pneumoniae, P>0.05 for H. influenzae, and P=0.005 for P. aeruginosa. P values for MRSA and MRCoNS were calculated using the χ2 test while ANOVA was used for the other isolate types.3
For the analysis by geography, isolates were categorized into 4 regions based on state of origin, including West (Alaska, Arizona, California, Colorado, Hawaii, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, and Wyoming), Midwest (Iowa, Illinois, Indiana, Kansas, Kentucky, Michigan, Minnesota, Missouri, North Dakota, Nebraska, Ohio, South Dakota, and Wisconsin), South (Alabama, Arkansas, Florida, Georgia, Louisiana, Maryland, Mississippi, North Carolina, Oklahoma, South Carolina, Tennessee, Texas, Virginia, and West Virginia), and Northeast (Connecticut, Delaware, Massachusetts, Maine, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, and Vermont).3