The trend of resistance to antibiotics for ocular infection of Staphylococcus aureus, coagulase-negative staphylococci, and Corynebacterium compared with 10-years previous: A retrospective observational study

PLoS One. 2018 Sep 7;13(9):e0203705. doi: 10.1371/journal.pone.0203705. eCollection 2018.


Objective: To retrospectively identify epidemiological trends of infection on the ocular surface and investigate trends of resistance to bacterial antibiotics compared with 10-years previous for Staphylococcus aureus, coagulase-negative staphylococci (CNS), and Corynebacterium in Japan.

Materials and methods: Bacterial isolate samples were collected from the conjunctival sacs of eyes afflicted with conjunctivitis, keratitis, dacryocystitis, and hordeolum from September 2004 through November 2005 (n = 145 isolates) and September 2014 through November 2015 (n = 195 isolates) at the Baptist Eye Institute, Kyoto, Japan. The prevalence of methicillin-resistant S. aureus (MRSA), methicillin-resistant CNS (MR-CNS), and fluoroquinolone-resistant Corynebacterium were examined, and susceptibility of isolated bacteria to levofloxacin (LVFX), cefmenoxime (CMX), chloramphenicol (CP), erythromycin (EM), vancomycin (VCM), and arbekacin (ABK) were compared between both time periods using the disc susceptibility method.

Results: Over the 10-year period from initial to final examination, the prevalence of MRSA and MR-CNS significantly decreased from 52% to 22% (P < 0.05) and from 47% to 25% (P < 0.05), respectively, yet there was no change in the prevalence of fluoroquinolone-resistant Corynebacterium (60% and 54%; P = 0.38). Antibiotic-resistance trend analysis revealed that susceptibility to antibiotics in 2014-2015 was similar to that in 2004-2005. MRSA and MR-CNS were susceptible to CP (88%), VCM (100%), and ABK (100%), while fluoroquinolone-resistant Corynebacterium was susceptible to CMX (100%), VCM (100%), and ABK (96%).

Conclusion: The prevalence of MRSA and MR-CNS significantly decreased between the two time periods, yet more than 50% of the Corynebacterium isolates were still resistant to LVFX. Although no increase in bacterial resistance to antibiotics was found, a cautionary use of fluoroquinolone eye drops should be considered.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / pharmacology*
  • Anti-Bacterial Agents / therapeutic use
  • Corynebacterium / drug effects*
  • Corynebacterium / physiology
  • Drug Resistance, Bacterial*
  • Eye Infections / drug therapy*
  • Female
  • Fluoroquinolones / pharmacology
  • Fluoroquinolones / therapeutic use
  • Humans
  • Male
  • Middle Aged
  • Retrospective Studies
  • Staphylococcal Infections / drug therapy*
  • Staphylococcus aureus / drug effects*
  • Staphylococcus aureus / physiology*


  • Anti-Bacterial Agents
  • Fluoroquinolones

Grant support

This study was supported in part by a Grant-in-Aid for scientific research from the Ministry of Education, Science, Culture, and Sports of Japan. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.