A case-control study to determine the microbiological spectrum and antibiotic sensitivity patterns in congenital nasolacrimal duct obstruction

Abstract

Purpose: To analyze the microbiological spectrum and antibiotic sensitivity patterns in children with congenital nasolacrimal duct obstruction (CNLDO). Methods: One hundred thirty-four eyes of 123 children in the age group of 0-16 years with a diagnosis of CNLDO who underwent lacrimal surgical procedures were included in this prospective comparative study. Sixty-two children in the age-matched group planned for intraocular surgery with patent nasolacrimal duct were deemed controls. The conjunctival swab after performing Regurgitation on Pressure over the Lacrimal Sac in the CNLDO group and the conjunctival swab in controls were sent for microbiological analysis. Antibiotic susceptibility testing was done for commonly employed antibiotics by the Kirby Bauer disk diffusion method. Results: Of 134 samples collected in the CNLDO group, 111 (82.8%) samples were culture positive. There were 165 bacteria isolated, among which 139 (84.24% of isolates) were Gram-positive bacteria, and 26 (15.75% of isolates) were Gram-negative. Fungal isolates were obtained in 2.23% of cases. The most common Gram-positive isolate was Staphylococcus epidermidis (S. epidermidis) (n = 51, 30.9% of total isolates), and the most common Gram-negative isolate was Haemophilus influenza species (n = 9, 5.5% of total isolates). Gram-positive isolates were sensitive mostly to gentamicin and vancomycin (95.5% each), and Gram-negative isolates to amikacin (92.3%). Both Gram-positive and Gram-negative isolates were susceptible to gatifloxacin (80% each). Probing outcomes were similar among Gram-positive (success, 84.6%) and Gram-negative (success, 84.0%) organisms. Conclusions: There was a predominance of Gram-positive isolates in children with CNLDO with S. epidermidis being the most common. The microbiological profile did not have any effect on the outcomes of probing.