Project description:Purpose: To identify the expression profiling of miRNA in peripheral blood of dairy cows in response to S. aureus-infected mastitis and explore the biomarkers for early diagnosis of S. aureus-infected mastitis. Methods: RNAseq technology was used to determine the expression profiles of microRNA (miRNA) from peripheral blood of Chinese Holstein cows infected with S. aureus at 0, 1, 3, 5, and 7 days. Results: Ttal of 288 differentially expressed miRNAs (DIE-miRNA) including 108 known and 180 novel predicted miRNAs, involved in 10 immune system-related signaling pathways. Compare with the 0 dpi, the number of DIE-miRNAs in 1, 3, 5, and 7 dpi groups were 12, 21, 75, and 48, respectively. It was also found that the expression variation of up-regulated expression of miR-320a, miR-19a, and miR-19b as well as down-regulated expression of miR-143, miR‑205, and miR‑24 reached a significant level on the 5 dpi and 7 dpi. However, at different times after S. aureus infection, miR-1301 was significantly up-regulated in peripheral blood. miR-2284r was significantly down-regulated. Conclusion: miR-1301 and miR-2284r might be the new blood biomarkers for S. aureus-infected dairy cow mastitis. The above results laid a new foundation for the research and development of molecular diagnosis and biological therapy technology for S. aureus-infected mastitis in dairy cow.
Project description:Background: S. aureus is one of the main pathogen involved in ruminant mastitis worldwide. The severity of staphylococcal infection is highly variable and ranges from subclinical to gangrenous mastitis. Such variability implies host as well as staphylococcal factors. This work is an in-depth characterization of S. aureus mastitis isolates to identify factors involved in mastitis severity. Methods and findings: We combined three “omic” approaches to comprehensively compare two clonally related S. aureus strains that were isolated from and shown to reproducibly induce severe (strain O11) and milder (strain O46) mastitis in ewes. The genomes of O11 and O46 were sequenced (Illumina technology) to determine their respective gene content and comparative transcriptomic and proteomic analyses were carried out on both strains grown in conditions mimicking mastitis context. High differences were highlighted in mobile genetic elements, iron acquisition and metabolism, transcriptional regulation and exoprotein production. In particular, O11 overproduced exoproteins, including toxins and proteases when compared to O46. This was confirmed in 4 other S. aureus strains isolated from subclinical or clinical mastitis cases. Dose-dependant production of some staphylococcal factors seem to play a role in hypervirulence of strains isolated from severe mastitis. Mobile genetic elements, transcriptional regulators, exoproteins or strain ability to deal with iron starvation constitute good targets for further research to better define the underlying mechanisms of mastitis severity. Conclusions: Differences observed in mastitis severity likely result from the ability of the strains to adapt and to express virulence factors in the mastitis context rather than from deep variations in gene content.
2011-11-11 | GSE25084 | GEO
Project description:Bacterial causes of camel mastitis
Project description:Background: S. aureus is one of the main pathogen involved in ruminant mastitis worldwide. The severity of staphylococcal infection is highly variable and ranges from subclinical to gangrenous mastitis. Such variability implies host as well as staphylococcal factors. This work is an in-depth characterization of S. aureus mastitis isolates to identify factors involved in mastitis severity. Methods and findings: We combined three “omic” approaches to comprehensively compare two clonally related S. aureus strains that were isolated from and shown to reproducibly induce severe (strain O11) and milder (strain O46) mastitis in ewes. The genomes of O11 and O46 were sequenced (Illumina technology) to determine their respective gene content and comparative transcriptomic and proteomic analyses were carried out on both strains grown in conditions mimicking mastitis context. High differences were highlighted in mobile genetic elements, iron acquisition and metabolism, transcriptional regulation and exoprotein production. In particular, O11 overproduced exoproteins, including toxins and proteases when compared to O46. This was confirmed in 4 other S. aureus strains isolated from subclinical or clinical mastitis cases. Dose-dependant production of some staphylococcal factors seem to play a role in hypervirulence of strains isolated from severe mastitis. Mobile genetic elements, transcriptional regulators, exoproteins or strain ability to deal with iron starvation constitute good targets for further research to better define the underlying mechanisms of mastitis severity. Conclusions: Differences observed in mastitis severity likely result from the ability of the strains to adapt and to express virulence factors in the mastitis context rather than from deep variations in gene content. Expression of S. aureus O46 from subclinical mastitis and O11 from a lethal gangrenous mastitis were compared at two different times
Project description:The regulatory effects of H3K27me3 on target genes expressions were analyzed by comparing S. aureus mastitis resistant and susceptible cows. The differentially expressed genes are mainly associated with immune and disease-related processes, which were negatively regulated by H3K27me3 modification on the up 2Kb regions relative to TSS in S. aureus mastitis cattle.
Project description:Ovine mastitis is defined as the inflammation of the sheep udder, most commonly caused in response to intramammary infections. Based on the occurrence of clinical signs, mastitis is characterized as either clinical or subclinical (SCM). The impact of ovine SCM on the overall sustainability of dairy sheep farms has been documented underpinning the significance of efficient diagnosis. Although SCM can be detected in cows, the performance and the validity of the methods used do not transfer in dairy sheep. This fact challenges the development of evidence-based ovine udder health management protocols and renders the detection and control of ovine mastitis rather problematic. Currently, cell culture-based models are being successfully used in biomedical studies and have also been effectively used in the case of bovine mastitis. The objective of the present study was to culture ovine primary mammary cells for the development of 2D and 3D cell culture-based models for the study of ovine SCM. Cells were infected by mastitis-inducing pathogens mimicking the pathogenesis of SCM as derived by natural intramammary infections. The secreted proteins were subjected to mass-spectrometry resulting in the identification of 79 distinct proteins. Among those, several had already been identified in healthy or mastitic milk, while others were detected for the first time in the ovine mammary secretome. The development of cell-based models for the early detection and the overall study of SCM has the potential to be applicable and beneficial for the udder health management in dairy sheep.
Project description:Mastitis is a common disease in dairy cows and brings massive losses to the dairy industry. m6A is a type of modification strongly associated with many diseases. However, the role of m6A in mastitis caused by Staphylococcus aureus and Escherichia coli has not been investigated.We used MeRIP-seq technology to sequence the bovine mammary epithelial cells (MAC-T) infected with inactivated S. aureus/E. coli for 24 h.
2020-11-09 | GSE161050 | GEO
Project description:Blood Transcriptome of Mastitis in Xinjiang Bactrian Camel, China
Project description:Mastitis is a common disease that hinders the development of dairy industry and animal husbandry. It leads to the abuse of antibiotics, the emergence of super drug-resistant bacteria, and poses a great threat to human food health and safety. Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) are the most common pathogens of mastitis in dairy cows and usually cause subclinical or clinical mastitis. CircRNAs and N6-methyladenosine (m6A) play important roles in immunological diseases. However, the mechanisms by which m6A modifies circRNA in bovine mammary epithelial cells remain poorly understood. The aim of our study was to investigate m6A-modified circRNAs in bovine mammary epithelial cells (MAC-T cells) injured by S. aureus and E. coli. The profile of m6A-modified circRNA showed a total of 1599 m6A peaks within 1035 circRNAs in the control group, 35 peaks within 32 circRNAs in the S. aureus group, and 1016 peaks within 728 circRNAs in the E. coli group. Compared with the control group, 67 peaks within 63 circRNAs were significantly different in the S. aureus group, and 192 peaks within 137 circRNAs were significantly different in the E. coli group. Furthermore, we found the source genes of these differentially m6A-modified circRNAs in the S. aureus and E. coli groups with similar functions according to GO and KEGG analyses, which were mainly associated with cells injury, such as inflammation, apoptosis, and autophagy. CircRNA-miRNA-mRNA interaction networks predicted the potential circRNA regulation mechanism in S. aureus- and E. coli-induced cell injury. We found that the mRNAs in the networks, such as BCL2, MIF and TNFAIP8L2, greatly participated in the MAPK, WNT, and inflammation pathways. This is the first report on m6A-modified circRNA regulation of cells under S. aureus and E. coli treatment, and sheds new light on potential mechanisms and targets from the perspective of epigenetic modification in mastitis and other inflammatory diseases.