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.

Hideto Deguchi,Kanae Kayukawa,Chie Sotozono,Toshihide Yamasaki,Koji Kitazawa,Akiko Fukumoto,Shigeru Kinoshita,Eri Kondoh,Karsten Becker

doi:10.1371/journal.pone.0203705

Abstract

ObjectiveTo 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 methodsBacterial 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.ResultsOver 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%).ConclusionThe 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.

Highlights

Ocular infections such as conjunctivitis and bacterial keratitis are acute or chronic infections that are often caused by the improper care and cleaning of contact lenses or trauma to the ocular surface, and may result in conjunctival scarring or severe keratitis, leading to loss of vision [1,2]
Over the 10-year period from initial to final examination, the prevalence of methicillin-resistant S. aureus (MRSA) and MRCNS 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)
The prevalence of MRSA and MR-coagulase-negative staphylococci (CNS) significantly decreased between the two time periods, yet more than 50% of the Corynebacterium isolates were still resistant to LVFX

Summary

Introduction

Ocular infections such as conjunctivitis and bacterial keratitis are acute or chronic infections that are often caused by the improper care and cleaning of contact lenses or trauma to the ocular surface, and may result in conjunctival scarring or severe keratitis, leading to loss of vision [1,2]. Staphylococcus aureus and coagulase-negative staphylococci (CNS), including Staphylococcus epidermidis, are important pathogens that reportedly lead to ocular surface infection [1]. MRSA is known to cause severe ocular surface infections that can lead to loss of vision, and our and others’ previous studies have reported that methicillin-resistant S. aureus (MRSA) and methicillin-resistant coagulase-negative staphylococci (MR-CNS) are highly resistant to various antibiotics [2,4,5,6,7]. Our and others’ studies have reported that vancomycin ophthalmic ointment 1% is effective for the treatment of intractable ocular MRSA and methicillin-resistant S. epidermidis (MRSE) infections [14,15]. There are currently few reports regarding the trend of antimicrobial resistance over a 10-year time period for the treatment of acute bacterial ocular infections [20]

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Results

Conclusion