A new screening approach has the potential to rapidly detect E. coli from milk in cases of bovine mastitis, which could pave the way for new field diagnosis options.
A team of researchers in Kazakhstan devised the technique, which repurposed the genome-editing method CRISPR-Cas12a alongside a DNA amplification approach known as Loop-mediated isothermal amplification, or LAMP.
The use of CRISPR enabled the scientists to identify target genetic sequences, and so to quickly determine whether E. coli was in milk samples, separately from other pathogens implicated in the condition such as Staphylococcus aureus and Streptococcus agalactiae.
The genetic sequence is ‘cut’ using the Cas12a enzyme, which results in a detectable fluorescent signal. The researchers went further, to test products drawn from the process in a lateral flow assay, which could be used to simplify detection and analysis.
Testing improvements needed
E. coli is one of the main causes of acute mastitis in dairy cattle, causing inflammation of the mammary gland and changes in milk. New tools enabling fast diagnosis in the field could help farmers respond quickly to reduce the economic impact of infections, which can be significant in both acute and subclinical cases.
“Compared to traditional diagnostic methods such as microbiology and PCR diagnostics, the CRISPR/Cas system offers several advantages. It is faster, more sensitive, and more specific, enabling earlier detection of mastitis and more accurate identification of the causative agent,” the authors wrote in the Journal of Agriculture and Food Research.
“Furthermore, the system can be easily adapted to detect other bacterial pathogens that cause mastitis such as Staphylococcus aureus and Streptococcus agalactiae.”
