Normal flora of conjunctiva and lid margin, as well as its antibiotic sensitivity, in patients undergoing cataract surgery at Phramongkutklao Hospital

Abstract

Objective

This study aimed to evaluate the normal flora of conjunctiva and lid margin, as well as its antibiotic sensitivity.

Design

This was a prospective cross-sectional study.

Patients and methods

A prospective study was conducted on 120 patients who underwent cataract surgery at the Phramongkutklao Hospital from September 2014 to October 2014. Conjunctival and lid margin swabs were obtained from patients before they underwent cataract surgery. These swabs were used to inoculate blood agar and chocolate agar plates for culturing. After growth of the normal flora, the antibiotic sensitivity method using tobramycin, moxifloxacin, levofloxacin, and cefazolin was applied.

Main outcome measures

Normal flora of conjunctiva and lid margin, along with its antibiotic sensitivity, from patients who underwent cataract surgery was assessed.

Results

A total of 120 eyes were included in this study, and bacterial isolation rates were identified. Five bacteria from the lid margin were cultured, namely, coagulase-negative staphylococcus (58.33%), Streptococcus spp. (2.5%), Corynebacterium (1.67%), Micrococcus spp. (1.67%), and Staphylococcus aureus (0.83%). Two bacteria from the conjunctiva were cultured, namely, coagulase-negative staphylococcus (30%) and Streptococcus spp. (0.83%). Results of antibiotic sensitivity test showed that all isolated bacteria are sensitive to cefazolin 100%, tobramycin 98.67%, levofloxacin 100%, and moxifloxacin 100%.

Conclusion

Coagulase-negative staphylococci are the most common bacteria isolated from conjunctiva and lid margin.

Keywords:

• conjunctival flora
• lid margin flora
• cataract surgery
• sensitivity
• antibiotics

Acknowledgments

The authors thank Dr Raveewan Choontanom, MD, Ophthalmologist, Department of Ophthalmology, Phramongkutklao Hospital, who provided both helpful comments and editorial support in the preparation of this manuscript. Additionally, the authors are also grateful to Dr Sudarat Thunyaharn, MSc, Microbiologist, Department of Microbiology, Faculty of Medicine, Phramongkutklao Hospital, for his valuable contribution to the collection of study information, sample collection and incubation, and the interpretations of antibiotic sensitivity in this study.

Disclosure

The authors report no conflicts of interest in this work.