Major age group-specific differences in conjunctival bacteria and evolution of antimicrobial resistance revealed by laboratory data surveillance.

Purpose: We hypothesized that observation and analysis of microbiological laboratory statistics from patients with suspected bacterial conjunctivitis should increase our understanding of microbiological epidemiology of the disease in age categories. We further assumed that the statistical data should expose evolution of antimicrobial resistance that may eventually have an influence on clinical decisions.
Materials and Methods: We analyzed statistical data of bacterial isolates (1139 strains) and their resistance to common antibiotics from 2494 patients with suspected bacterial conjunctivitis.
Results: Streptococcus pneumoniae, Haemophilus influenzae, and Staphylococcus aureus displayed their presence in 0- to 5-year-old children. Staphylococcus aureus and Pseudomonas aeruginosa were the most common in the elderly (>age 70) among whom a rapid increase in resistance of Staphylococcus aureus to methicillin (MRSA) was recognized.
Conclusions: Our study demonstrates that the spectrum of conjunctival bacteria varies among age groups. In addition, our results confirm that a shift in antimicrobial susceptibility can be rapid and age-group specific, thus emphasizing the need for continuous surveillance of bacterial findings.