Remodelling of the healthy foal's conjunctival microbiome in the first two months of life

Introduction The aim of the study was to explore and characterise healthy foals' eye microbiomes in the first two months of life.Material and Methods Conjunctival swabs were collected three times, not later than 12 h after delivery and again at the end of the first and the second months of life from six clinically healthy foals of the Polish Konik breed. The average interval between the first and second samplings was 33.3 days and between the second and third was 35.6 days. Next-generation sequencing performed on a MiSeq sequencer in paired-end technology was used to analyse the composition of the conjunctival microbiota.Results Paired one-sided t-tests revealed that conjunctival microbiota diversity was the lowest in the first 24 h of life and significantly increased between birth and the first month. The most prevalent family throughout the study was Micrococcaceae and the most prevalent genus was Corynebacterium. Sequences of potentially pathogenic bacteria such as Pseudomonas, Acinetobacter and Streptococcus spp. that may be involved in inflammatory processes were identified. Ocular commensals such as Corynebacterium and Lactobacillaceae that were found in the ocular surface microbiome of the foals are believed to be capable of restoring the ocular microbiome and maintaining balance.Conclusion A healthy ocular surface microbiota in the early period of a foal's life develops dynamically and changes its composition.