The differential gene expressions of rat mucosa colonized with single or multi-species of MRSA or PA were studied using RNA-sequencing of total transcriptome.

The differential gene expressions of rat mucosa colonized with single or multi-species of MRSA or PA were studied using RNA-sequencing of total transcriptome. In multi-species in-vitro biofilms PA partially inhibited SA growth. However, no significant inhibition of MRSA was detected during in-vivo colonization of multi-species in rat bullae. A total of 1797 genes were significantly (p < 0.05) differentially expressed in MRSA or PA or MRSA+PA colonized rat middle ear mucosa with respect to the control. The poly-microbial colonization of MRSA and PA induced the differential expression of a significant number of genes that are involved in immune response, inflammation, signaling, development, and defense; these were not expressed with single species colonization by either MRSA or PA. Genes involved in defense, immune response, inflammatory response, and developmental process were exclusively up-regulated, and genes that are involved in nervous system signaling, development and transmission, regulation of cell growth and development, anatomical and system development, and cell differentiation were down-regulated after multi-species inoculation. Overall design: S. aureus (MRSA), Pseudomonas aeruginosa (PA) or mixed culture (MRSA +PA) were inoculated in rat middle ear and incubated for 1 week. Vehicle control animals were inoculated with media only. Rats were sacrificed and middle ear mucosa were removed. Total RNA was isolated and sequenced for gene expression study. Differential gene expression in SA colonization, PA colonization or mixed species colonization were evaluated with respect to media only (vehicle control).

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Yadav MK, Chae SW, Go YY, Im GJ, Song JJ