ABSTRACT
Background Dacryocystitis is one of the most common infectious eye diseases.The gold standard for the identification of bacteria causing dacryocystitis is bacterial culture.The combination of regular culture method with molecular biology techeniques will generate more reliable results.However,very few research data are available in ophthalmological studies in this area.Objective This study was to identify the genera and species of the dacryocystitis-causing bacteria by PCR amplification of the 16S rRNA sequences.Methods Ten cases of qualified standardized bacteria samples were taken,and the nucleic acids were released in the heating process of the PCR procedure.The 16S rRNA genes were amplified and sequenced,and the genera and species were identified using BLAST from GenBank,and the results were used to compare with the results from biochemical identification to test the reliability of this method.The cultured bacterial species from the lacrimal sac secretions from 30 cases of dacryocystitis patients were identified with the above method.Results The outcome of the PCR identification for the 10 cases of quality control standard bacterial specimens was consistent with the results from the biochemical identification.The identification of the 30 cases of dacryocystitis through sequencing the 16S rRNA revealed there were 13 cases of Staphylococcus epidermidis infection,2 cases of Staphylococcus warneri infection,1 case of Staphylococcus hominis infection,5 cases of Corynebacterium macginleyi infection,3 cases of Streptococcus pneumonia infection,2 cases of Bacillus cereus infection,1 case of Micrococcus luteus infection,1 case of Moraxella catarrhalis infection,1 case of Moraxella osloensis infection and 1 case of Pseudomonas aeruginosa infection.Conclusions Sequencing the 16S rRNA is an accurate and specific way for the identification of the genera and species of bacteria that cause dacryocystitis in patients.This sequencing method is feasible in monitoring a variety of dacryocystitis-causing pathogens.More information and epidemiological statistics about dacryocystitis can be obtained from 16S rRNA sequencing.