The aim of this study was to investigate the pathogenic factors, pathogen distribution and drug resistance of infectious endophthalmitis.

The clinical data of 1364 patients (1364 eyes) checked in Shanxi Eye Hospital from January 2011 to December 2020 who may be infected by infectious endophthalmitis were retrospectively analyzed. Among of them, 1159 cases (1159 eyes) were male and 205 cases (205 eyes) were female. The patients were 1 to 83 years-old with an average age of (47.3±13.5) years-old. The anterior aqueous humor and vitreous fluid were extracted for pathogen culture, identification and drug sensitivity test. The clinical characteristics of endophthalmitis patients, and the distribution of pathogens and the drug resistance of main pathogens were analyzed by WHONET5.6 software. The distribution of pathogenic bacteria and pathogenic factors of infectious endophthalmitis were described by the number and percentage.

After pathogenic bacteria examination, 341 patients (341 eyes) were diagnosed as infectious endophthalmitis. Among of 341 cases (341 eyes) of infective endophthalmitis, males aged 15 to 65 years-old were the main pathogenic age group. There were 339 cases (339 eyes) of exogenous endophthalmitis, and 2 cases (2 eyes) of endogenous endophthalmitis. The main pathogenic factor was ocular trauma, followed by internal eye surgery. There were 257 cases (257 eyes) of vitreous fluid and 84 cases (84 eyes) of aqueous humor. Among of the pathogenic bacteria, there were 271 strains of Gram-positive bacteria (79.5%), mainly Staphylococcus epidermidis and Streptococcus, of which 131 strains (131 eyes) of Staphylococcus epidermidis accounting for 48.3%, 53 strains (53 eyes) of Streptococcus accounting for 19.6%. There were 92 strains (92 eyes) of methicillin-resistant Staphylococcus epidermidis, accounting for 70.2%. According to minimum inhibitory concentration (90%), the strains were highly resistant to penicillin and ampicillin (more than 90%); the resistant to erythromycin, levofloxacin and cotrimoxazole for strains were more than 50%; no Staphylococcus epidermidis resistant to vancomycin and linezolid was found. More frequent seanson that affected by endophthalmitis was in summer during the period of ten years.

The incidence of exogenous endophthalmitis of infectious endophthalmitis was higher than others. Age, trauma and intraocular surgery were risk factors for infectious endophthalmitis. The incidence of infectious endophthalmitis after cataract surgery was higher. Vancomycin and linezolid were highly sensitive to vancomycin.