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Updated: Jan 2, 2026
Evaluation of Microbial Safety of Dairies using Bacterial Proteomic Profiling via MALDI Approach
Published on: October 7, 2025
Identification and characterization of differentially expressed exosomal microRNAs in bovine milk infected with
Shaoyang Ma1, Chao Tong1, Eveline M Ibeagha-Awemu2
1College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China.
Background:
MicroRNAs (miRNAs) in milk-derived exosomes may reflect pathophysiological changes caused by mastitis. This study profiled miRNAs in exosomes from both normal milk and mastitic milk infected by Staphylococcus aureus (S. aureus). The potential targets for differentially expressed (DE) miRNAs were predicted and the target genes for bta-miR-378 and bta-miR-185 were also validated.
Results:
Total RNA from milk exosomes was collected from healthy cows (n = 3, the control group) and S. aureus infected cows (n = 6, the SA group). Two hundred ninety miRNAs (221 known and 69 novel ones) were identified. Among them, 22 known and 15 novel miRNAs were differentially expressed. Target genes of DE miRNAs were significantly enriched in intracellular protein transport, endoplasmic reticulum and identical protein binding. The expression of two miRNAs (bta-miR-378 and bta-miR-185) with high read counts and log2 fold changes (> 3.5) was significantly higher in mastitic milk infected with S. aureus. One target gene (VAT1L) of bta-miR-378 and five target genes (DYRK1B, MLLT3, HP1BP3, NPR2 and PGM1) of bta-miR-185 were validated.
Conclusion:
DE miRNAs in exosomes from normal and S. aureus infected milk were identified. The predicted targets for two DE miRNAs (bta-miR-378 and bta-miR-185) were further validated. The linkage between the validated target genes and diseases suggested that we should pay particular attention to exosome miRNAs from mastitic milk in terms of milk safety.
Insights
MicroRNAs (miRNAs) in milk exosomes can indicate mastitis. This study identified differentially expressed miRNAs in Staphylococcus aureus-infected milk, validating targets for bta-miR-378 and bta-miR-185, highlighting their role in milk safety.
Area of Science:
- Veterinary Science
- Molecular Biology
- Biochemistry
Background:
- Milk-derived exosomes contain microRNAs (miRNAs) that may signal pathophysiological changes associated with mastitis.
- This study investigated miRNA profiles in exosomes from normal and Staphylococcus aureus (S. aureus)-infected mastitic milk.
Purpose of the Study:
- To profile and identify differentially expressed (DE) miRNAs in exosomes from S. aureus-infected mastitic milk compared to normal milk.
- To predict and validate target genes of specific DE miRNAs, namely bta-miR-378 and bta-miR-185.
Main Methods:
- Exosomes were isolated from milk of healthy (control) and S. aureus-infected (SA) cows.
- Total RNA was extracted, and miRNA sequencing was performed to identify known and novel miRNAs.
- Bioinformatic analyses were used to predict target genes, and quantitative real-time PCR was employed for validation.
Main Results:
- A total of 290 miRNAs (221 known, 69 novel) were identified, with 22 known and 15 novel miRNAs found to be differentially expressed.
- DE miRNA targets were enriched in pathways related to intracellular protein transport and endoplasmic reticulum.
- The expression of bta-miR-378 and bta-miR-185 was significantly elevated in mastitic milk, with specific target genes validated.
Conclusions:
- This study identified DE miRNAs in milk exosomes from normal and S. aureus-infected mastitic milk.
- The validated target genes of bta-miR-378 and bta-miR-185 provide insights into the molecular mechanisms of mastitis.
- The findings underscore the importance of monitoring exosome miRNAs in mastitic milk for ensuring milk safety.
