Abstract:

Objective To observe drug sensitivity and resistance of ocular isolated bacteria to commonly-used antibiotics. Design Experimental study. Participants 2271 positive samples collected between January 2007 to December 2013 in Beijing Institute of Ophthalmology, Beijing Tongren Hospital. Methods Ocular isolated bacteria was identified using ATB semi-automatic identification instrument with bacterial suspension. Ophthalmic antimicrobial susceptibility of culture-positive microorganisms was tested using Kirby-Bauer disk diffusion method. The results are judged by 2012 edition of CLSI standard. Main Outcome Measures Drug sensitivity and resistance of ocular isolated bacteria. Results Among 2271 bacteria samples, 1514 cases (66.67%) were Gram-positive cocci, 261 cases(11.49%) were Gram-positive bacilli, 28 cases (1.23%) were Gram-negative cocci, 468 cases (20.61%) were Gram-negative baccilli. The most common Gram-positive bacteria was Staphylococcus epidermidis, followed by Staphylococcus aureus, Streptococcus mitis and Streptococcus pneumonia. The most common Gram-negative bacteria was Pseudomonas aeruginosa. Staphylococci are sensitive to vancomycin. The detection rate of Methicillin-resistant Staphylococcus is 59.4%. The resistance rates of Staphylococcus, Streptococcus, Enterococcus, Corynebacterium and non-fermentative bacteria to ceftazidime are 65.1%, 22.1%, 92.3%, 34.4% and 26.1% respectively. 0.3% of streptococcus strains are not sensitive to vancomycin. The resistance rates of Enterococcus to commonly-used ophthalmic antibiotics are significantly higher than other strains; few vancomycin-intermediate strains are seen. The resistance rates of non-fermentative bacteria and Enterobacteriaceae to moxifloxacin are 27.3% and 23.9%, slightly higher than other drugs. Conclusion Most ocular bacteria have higher sensitivity to quinolones. Vancomycin-resistant strains are not detected in Staphylococcus. Higher resistance rates to Cephalosporin antibiotics are seen in most bacteria; the drug resistance of Enterococcus to most commonly-used antibiotics is high especially. (Ophthalmol CHN, 2014, 24: 262-267)

Key words: eye infections, bacterial, bacterial resistance, susceptibility testing, multi-drug resistant