Comparison of the ocular microbiome between chronic Stevens-Johnson syndrome patients and healthy subjectsOriginal paper
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease, four years before the first published case study.
Read MoreWhat was studied?
This study compared the ocular surface microbiome of chronic Stevens-Johnson syndrome patients with healthy subjects. Conjunctival swabs from the inferior fornix were analyzed by two methods: conventional bacterial culture and next-generation 16S rRNA gene sequencing. Sequencing targeted the V3-V4 regions on an Illumina MiSeq platform. The team measured culture positivity, antimicrobial susceptibility, alpha diversity (Shannon index), beta diversity, and taxonomic composition, and related findings to a chronic ocular severity score.
Who was studied?
This was a prospective, age and sex matched study of 20 chronic Stevens-Johnson syndrome patients and 20 healthy subjects, recruited at a hospital in Bangkok, Thailand. One eye per person was swabbed, giving 40 specimens total. The group was 10 men and 30 women, with mean age 44.5 years in patients and 44.2 in controls. Disease onset ranged from 3 months to 30 years, most commonly drug-induced. Recent contact-lens, antibiotic, and eye-surgery cases were excluded.
What were the most important findings?
Positive bacterial cultures were far more common in patient eyes than healthy eyes: 60 percent versus 10 percent (p equals 0.001). Higher ocular severity scores tracked with culture positivity, with median score 12 in culture-positive versus 1 in culture-negative eyes (p equals 0.016). Sequencing showed greater diversity in patients, with a higher Shannon index (p equals 0.0063). In patients the dominant phyla were Proteobacteria (34.8 percent), Firmicutes (23.8 percent), Bacteroidetes (13.1 percent), Tenericutes (11.9 percent), and Actinobacteria (9.8 percent). Potential pathogens including Pseudomonas, Staphylococcus, Streptococcus, and Acinetobacter were more prevalent, and Burkholderiaceae and Enterobacteriaceae appeared as patient-specific core families.
What are the greatest implications of this study?
The findings show that the ocular surface in chronic Stevens-Johnson syndrome is colonized by more diverse and more pathogenic bacteria than healthy eyes. This altered community may fuel chronic inflammation and raise the risk of opportunistic infection. The authors suggest that culture-guided antibiotic choice should be a first-line consideration in these patients. The study was small and mainly involved Thai people, so results may best generalize to Southeast Asian populations and need confirmation in larger cohorts.