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PurposeThis study aimed to determine the composition and diversity of bacterial communities on the ocular surface before and after the intervention with sodium hyaluronate eye drops (with or without preservatives) using 16S rRNA gene amplicon sequencing.MethodsSixteen healthy adults were randomly divided into two groups and treated with sodium hyaluronate eye drops with or without preservatives for 2 weeks. The individuals used the same artificial tears in both eyes. The microbial samples from the conjunctival sac of each participant were collected at baseline and 2 weeks after intervention. The diversity and taxonomic differences among different groups before and after intervention were compared by sequencing the V3–V4 region of the 16S rRNA gene.ResultsThe similarity in the binocular microbial community was high in 1 of the 16 volunteers (Bray-Curtis dissimilarity score < 0.3). At the genus level, 11 bacteria were detected in all samples with an average relative abundance of more than 1%. The bacterial community changed significantly after the use of sodium hyaluronate eye drops (with or without preservatives), whether within individuals or between individuals in different groups (P < 0.05, PERMANOVA). Different dosage forms of sodium hyaluronate eye drops significantly decreased the relative abundance of Flavobacterium caeni and Deinococcus antarcticus, respectively (P < 0.05).ConclusionsHealthy people had a rich diversity of the bacterial microbiota on the ocular surface, but the bacterial communities between the eyes were not completely similar. Irrespective of containing benzalkonium chloride (BAC), sodium hyaluronate eye drops can change the bacterial community on the ocular surface.

A Gram-stain-negative, rod-shaped, facultative anaerobic bacterium, designated strain 3539T, was isolated from coastal sediment of Weihai, PR China. Optimal growth occurred at 28 °C, pH 7.5–8.0 and in the presence of 3.0 % (w/v) NaCl. Results of phylogenetic analysis based on 16S rRNA gene sequences revealed that strain 3539T formed a robust clade with members of the genus Marinicella and was closely related to Marinicella litoralis JCM 16154T, Marinicella sediminis F2T and Marinicella pacifica sw153T with 97.7, 96.2 and 95.4 % sequence similarity, respectively. The average amino acid identity, percentage of conserved proteins, average nucleotide identity and digital DNA–DNA hybridization values between strain 3539T and M. litoralis JCM 16154T were 64.9, 68.3, 72.8 and 18.9 %, respectively. The genomic DNA G+C content of strain 3539T was 42.0 mol%. The dominant respiratory quinone was ubiquinone-8, and the major fatty acids were iso-C15 : 0 and summed feature 3 (C16 : 1  ω7c/C16 : 1  ω6c). The polar lipids of strain 3539T consisted of phosphatidyldimethylethanolamine, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, one unidentified aminophospholipid, one unidentified lipid and three unidentified phospholipids. Based on the combination of phylogenetic, phenotypic and chemotaxonomic data, strain 3539T is considered to represent a novel species within the genus Marinicella in he family Alcanivoracaceae , for which the name Marinicella rhabdoformis sp. nov. is proposed. The type strain of the new species is 3539T (=KCTC 72414T=MCCC 1H00388T).

Purpose. To investigate the changes of corneal endothelium under different crosslinking conditions and the protective effect of ripasudil. Methods. Corneal crosslinking groups were infiltrated with riboflavin and subsequently irradiated with 0.54 J/cm2 or 1.08 J/cm2 UVA, while noncrosslinking groups included neither UVA nor riboflavin treatment, only 1.08 J/cm2 UVA and only riboflavin treatment. Corneal opacity, variations in corneal endothelial cells, and corneal thickness of all groups were observed by slit lamp, in vivo confocal microscopy, and optical coherence tomography. Immunofluorescence staining and scanning electron microscopy were performed to evaluate changes in the structure and function of the corneal endothelium. The mice that received a corneal crosslinking dose of 1.08 J/cm2 were instilled with ripasudil to explore its protective effect on the corneal endothelium. Results. Treatment with UVA and riboflavin caused an increase in corneal opacity and corneal thickness and decreased endothelial cell density. Furthermore, treatment with UVA and riboflavin caused endothelial cell DNA damage and destroyed the tight junction and pump function of the endothelium, while riboflavin or the same dose of UVA alone did not affect the endothelium. Ripasudil reduced DNA damage in endothelial cells, increased the density of cells, and protected the endothelium’s integrity and function. Conclusion. Riboflavin combined with UVA can damage the corneal endothelium’s normal functioning. The corneal endothelium’s wound healing is dose-dependent, and the ROCK inhibitor ripasudil maintains the endothelium’s pump and barrier functions.