LAUSR

Purpose This study aimed to determine the susceptibility and the changes of bacterial agents of chronic dacryocystitis and determine the risk factors for bacterial prevalence and drug sensitivity to provide a reference for clinical selection of antibiotics. Methods A case–control study was conducted using 112 patients with chronic dacryocystitis and 112 patients with non-infectious ophthalmopathy between August 2017 and April 2018. Lacrimal and conjunctival sac secretions were cultured for aerobic and anaerobic bacteria. Forty-five patients with chronic dacryocystitis between November 2014 and November 2015 were also included. Results Positive bacterial cultures were obtained from 61.9% and 50.9% of chronic dacryocystitis and non-infectious ophthalmopathy patients, but the detection rates for pathogenic bacteria were 18.3% and 2.7%, respectively ( P > 0.001). Gram-negative and anaerobic bacteria were significantly more prevalent in the patient group compared with the control group ( P  = 0.001 and 0.005, respectively). Bacteria were detected at a significantly higher rate in patients with irritant symptoms (itch or foreign-body sensation) than in those without (OR = 9.333, P  = 0.002), particularly Staphylococcus (OR = 9.783, P  = 0.002). 11.6% (10/86) and 55.8% (48/86) showed resistance to levofloxacin and tobramycin, respectively. Compared with three years ago, the detection rate for Gram-positive cocci decreased from 51.1% to 27.8% ( χ 2  = 8.054, P  = 0.005) Conclusions Gram-positive cocci, Gram-negative bacilli, and anaerobic bacteria were the predominant pathogens. The prevalence of Gram-positive bacteria in cases of chronic dacryocystitis is decreasing.