TRANSCRIPTOMIC ANALYSIS OF DIFFERENTIAL GENE EXPRESSION IN STAPHYLOCOCCUS AUREUS-INDUCED PNEUMONIA IN PEDIATRICS BASED ON MICROARRAY ANALYSIS

Leonard O. Ehigie, Fiyinfoluwa D. Ojeniyi, Adetayo Aborisade, Sulaimon Nassar, Christopher Igbeneghu, James Busayo Agboola and Adeola F. Ehigie*

ABSTRACT

Background: Staphylococcus aureus is a leading cause of about 80% of infections in humans and up to 60–70% of hospital-acquired infections. Identification of an etiologic agent for pneumonia is critical in order to provide appropriate therapy and maintain epidemiological records. Study on the transcriptional profiling of patients infected with S. aureus is a pivot to the analysis of differentially expressed gene in the blood of patients infected with S. aureus. This study performed the analysis of gene expression dataset GSE30119 available on the Gene expression Omnibus (GEO) which is based on the hypothesis tested that patient clinical heterogeneity will be reflected in transcriptional profile heterogeneity. Methods: Gene expression profile dataset GSE30119 was obtained from Gene Expression Omnibus (GEO). We performed bioinformatic analysis to identify Differentially Expressed Genes in S. aureus infection induced Pneumonia from the transcriptional level. The study comprised 143 pediatric patients, with 44 healthy individuals, 81 pneumonia-free, and 18 pneumonia infection patients. Gene Ontology (GO) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) functional, and pathway enrichment analyses were performed using Metascape. STRING and Cytoscape were used for the construction and visualization of biological networks. Hub-genes were identified through degree of association of interaction networks. Results: We discovered a total of 54 genes related to S. aureus infection and 612 genes associated with Pneumonia. According to Gene Ontology (GO) functional and pathway enrichment studies, the S. aureus infection associated genes are predominantly engaged in the innate immune response, calcium-mediated signaling, Neutrophil extracellular trap formation, Formation of Fibrin Clot (Clotting Cascade). Whereas the genes associated with Pneumonia are enriched in adaptive immune response, inflammatory, Interferon alpha/beta signaling, TCR signaling, Gα(i) signalling events. Conclusions: This study shows differentially expressed genes and their biological activities in relation to S. aureus infection and Pneumonia, and it may provide more light on the underlying molecular mechanisms and possibly important gene signatures in Pneumonia development.

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