Purpose:
To study microbiologic characteristics of bacterial keratitis cases in Shanghai, and to explore the association between history and culture isolates from these patients.
Methods:
This is a retrospective multicenter case series. A total of 1303 patients with bacterial keratitis presenting to participating tertiary eye care centers. Medical records were reviewed for all bacterial keratitis cases confirmed by culture, histology, or clinical investigation between January 1, 2005, and December 31, 2010, at five tertiary clinical sites in Shanghai. Bacterial isolates wereidentified and tested for antibiotic susceptibility. A logistic regression analysis was conducted with bacterial species as the main outcome variable and age, gender, educational levels, contact lens wearing, ocular surface disease, ocular surgery, ocular trauma, cigarette smoking and presence of diabetes as potential predictive variables.
Results:
545 patients with positive culture were finally identified. In those positive cultures, Pseudomonas species, Streptococcus species and Staphylococcus species represented 31.4%, 15.8% and 15.6%, respectively. 80.6% of the gram-positive isolates were susceptible to gatifloxacin, whereas 63.0% and 59.5% were susceptible to levofloxacin and tobramycin. For the gram-negative isolates, 91.2%, 84.4% and 80.5% were susceptible to gatifloxacin, levofloxacin and tobramycin, respectively. Lower educational levels (P=0.018), ocular surface disease (P=0.015), oculartrauma (P=0.002), cigarette smoking (P<0.001) and presence of diabetes (P=0.039) were associated with increased odds of gram-positive bacterial infection. However, contact lens wearing (P=0.001) was associated with increased odds of gram-negative bacterial infection.
Conclusions:
Educational levels, contact lens wearing, ocular surface disease, trauma, cigarette smoking and history of diabetes in bacterial keratitis cases may be useful for choosing empiric antibiotic treatment before pathogenic bacteria was identified.
Keywords: clinical (human) or epidemiologic studies: natural history • keratitis • cornea: clinical science