A study led by Professor Beatriz Prieto‑Simón and published in ACS Measurement Science presents a new method to detect bovine mastitis at an early stage. The approach relies on analysing the host’s immune response rather than identifying the pathogen itself. The ICIQ team developed electrochemical DNA biosensors that detect specific microRNAs in milk, using samples collected under natural farm conditions and without inducing disease.
The work highlights a change in diagnostic strategy. Instead of searching directly for infectious agents, the method focuses on how the animal responds to infection. This makes it possible to identify disease earlier, even in the absence of visible symptoms. Mastitis is one of the main health problems affecting dairy cattle. It has a direct impact on animal welfare, as it causes inflammation of the mammary gland and can lead to pain and discomfort. It is also a major issue for the dairy industry. The disease reduces milk yield and quality, and in severe cases can lead to animal loss.
A particular challenge is the subclinical form of mastitis. This form shows no visible signs, yet it is more common than the clinical one and can spread within herds. Diagnosis remains difficult. Standard laboratory methods such as microbiological culturing and PCR are time‑consuming, costly, and not suited to on‑farm use. Immunoglobulin‑based tests also have limitations. Antibodies become detectable only weeks after infection and require laboratory analysis. As a result, early detection in real conditions is still limited.
The proposed approach addresses this gap through the analysis of microRNAs. These small RNA molecules regulate gene expression and act as switches in immune cell activation. Changes in their levels reflect the host’s immune status. The researchers identified a specific signature of three microRNAs, miRNA‑146b, miRNA‑221 and miRNA‑223, that differs between healthy cows and those with subclinical mastitis.
To detect these molecules, the team developed electrochemical biosensors that analyse RNA extracted from milk. The sensors are based on DNA probes attached to gold electrodes. When a target microRNA binds to the probe, it produces a measurable electrochemical signal. This allows detection without complex sample preparation or amplification steps. The system is designed to be fast, sensitive, and suitable for portable use on farms. The study shows that these sensors can distinguish between healthy and infected animals using real milk samples. This supports their potential as practical tools for early diagnosis and improved disease management.
As Prof. Prieto‑Simón explains, “The development of simple, sensitive, and specific sensors targeting unique signatures of host immune-derived biomarkers promises a new framework to improve disease management and antimicrobial stewardship.”
Early and reliable detection of mastitis is essential to improve animal welfare and farm management. It also plays an important role in reducing antimicrobial use. Because mastitis accounts for a large share of antibiotic treatments in dairy farming, better diagnostics could help limit unnecessary use and contribute to tackling antibiotic resistance.
Reference publication
Amplification-Free Detection of MiRNA Signatures in Milk: A Noninvasive Sensing Approach for Early Diagnosis of Bovine Mastitis
Shafique, K.; Haji-Hashemi, H.; Gontar, Ł.; Pīlmane, M.; Maróti, G.; Prieto-Simón, B.
ACS Meas. Sci. Au 2026
DOI: 10.1021/acsmeasuresciau.6c00060
La entrada Biomarkers found in milk enable earlier detection of bovine mastitis se publicó primero en ICIQ.