Alternative methods aid identification of pathogens in bacterial conjunctivitis
Bacterial cell counts and microbiota analysis were effective as adjunct methods of isolating causative pathogens in eyes with bacterial conjunctivitis, according to a study.
The study included 13 eyes of 13 patients with clinically diagnosed bacterial conjunctivitis; a control group comprised 12 eyes with normal conjunctival sacs. Average patient age was 82.5 years in the bacterial conjunctivitis group and 72.9 years in the normal conjunctiva group.
Ethidium bromide was used to stain samples and count bacterial cell numbers. The investigators used the clone library method with polymerase chain reaction (PCR) amplification of the 16S ribosomal RNA (rRNA) gene to determine microbiota. They also examined smears and cultures.
Study results showed positive PCR results for the 16S rRNA gene in 10 of 13 samples from eyes with bacterial conjunctivitis; PCR results were negative in the remaining three diseased samples and all 12 normal samples.
The predominant species accounted for 84.5% or more of each clone library in five of the 10 PCR-positive samples.
Bacteria were identified in eight of the 10 bacterial conjunctivitis samples and in five of the 12 normal culture samples, the authors said.