Detection of Critical Genes Associated with Bovine Staphylococcus aureus (S. aureus) Subclinical Mastitis in Dairy Cattle

Bovine mastitis, is one of the most common diseases of dairy cattle which is responsible for the rate of elimination, low milk yield and poor milk quality; therefore, it induces significant economic losses in the dairy cattle industry [1]. S. aureus, a Gram-positive pathogenic bacterium, is a major subclinical mastitis-causing pathogen in dairy cattle which is usually asymptomatic, persistent, resistant to antibiotic treatment and easily reoccur [2]. In order to get a higher power of statistical analysis, meta-analysis were used in the current study to combine p-values obtained from individual analysis of datasets extracted from 10 microarray-based datasets which investigate transcriptomic data of mammary gland tissue infected by S. aureus in dairy cows. 185genes showed significantly differentially expressed after meta-analysis (44 genes down and 141 genes up regulate respectively). Sub-Network Enrichment Analysis (SNEA) were used to predefine gene sets which have more significant expression changes downstream targets using pathway studio software [3] on differentially expressed genes. Direct regulatory network between the SENA gene seeds were retrieved and displayed by Pathway studio software. Twenty-two critical genes including extracellular proteins such as: C-X-C motif chemokine ligand 8 (CXCL8), Interleukine 10 (IL10), C -C motif chemokine ligand 3 ( CCL2) and membrane protein such as: Toll like receptor 2 (TLR2) were detected through applying 12 different ranking algorithms of Cytohubba plugin in Cytoscape software on direct regulatory network of SNEA gene seeds .

Keywords:

Meta-analysis , Microarray , Transcriptom , S.aureus , SNEA