# Bacteriologic profile and antimicrobial resistance in infants aged 1 year or younger with congenital nasolacrimal duct obstruction

## TL;DR

This study identifies common bacteria in infants with a blocked tear duct and finds which antibiotics are most effective.

## Contribution

The study provides a detailed antimicrobial resistance profile specific to infants with congenital nasolacrimal duct obstruction.

## Key findings

- Staphylococcus species were the most common bacteria found in infants with CNLDO.
- Moxifloxacin and levofloxacin showed the highest effectiveness against the isolated bacteria.
- High resistance was observed for erythromycin, clindamycin, and tetracycline.

## Abstract

The aim of the study was to evaluate conjunctival flora and antibiotic susceptibility in infants aged 1 year or younger with congenital nasolacrimal duct obstruction (CNLDO), creating an overall profile of antimicrobial susceptibility.

Retrospective.

The analysis was conducted at the Kazakh Eye Research Institute over a period of 6 years, from January 2017 to December 2022. Cultures were grown on various agars for bacterial and fungal analyses, with sensitivity testing via Vitek 2 Compact.

We examined 1210 conjunctival cultures from infants with CNLDO, yielding 1212 isolates. Most were gram-positive bacteria (77.15%), with fewer gram-negative bacteria (22.28%) and fungi (0.57%). Among the gram-positive bacteria, Staphylococcus species (61.06%) were predominant, including S epidermidis (17.49%), S aureus (10.73%), and S saprophyticus (9.32%). Enterococcus species (6.52%) and Streptococcus species (6.02%) followed. Among the gram-negative bacteria, Escherichia coli (5.78%) was most prevalent, followed by Pseudomonas species. (4.54%), Enterobacter cloacae (3.71%), and Klebsiella species (3.63%). The majority of the fungi were Candida albicans, accounting for 4 isolates (0.33%). Most of the bacteria showed high sensitivity to moxifloxacin (92.52%), levofloxacin (88.99%), gentamicin (86.74%), vancomycin (86.52%), cefotaxime (85.27%), and ofloxacin (85.62%). High resistance was noted for erythromycin (32.84%), clindamycin (28.13%), and tetracycline (21.65%).

In this study, we identified Staphylococcus, Enterococcus, and Streptococcus species and E coli as key CNLDO bacteria and highly responsive to antibiotics like levofloxacin and moxifloxacin. These findings guide effective antibiotic choices for CNLDO treatment, aiding in the prevention of antibiotic resistance.

The online version contains supplementary material available at 10.1007/s10384-025-01197-0.