Narsingh R. Nirala
Giorgi Shtenberg
Bovine mammary gland is susceptible to numerous bacterial infections resulting in inflammatory disease condition of bovine mastitis (BM) with a staggering economic impact on the dairy industry worldwide. Early BM detection is crucial for infection control within the dairy herd, which can be alleviated by antimicrobial therapy. N-acetyl-β-D-glucosaminidase (NAGase) is a prominent BM inflammatory biomarker secreted onto the blood circulation upon pathogenesis and then released into milk, capable of separating healthy quarters from subclinical and clinical BM cases. Herein, we report a sensitive, cost-effective and handy-to-use BM severity assay based on NAGase inherent content found in whole milk samples. Silver-coated porous Si (Ag-PSi) Fabry–Pérot interferometers were employed for quantifying the lysosomal activity in different milk qualities using surface-enhanced Raman spectroscopy (SERS). The optical response was proportional to the occurring pathogenesis induced by predominant bacteria found in dairy farms at different somatic cell levels. The optimized Ag-PSi SERS substrates were utilized for quantitative analysis of NAGase levels found at clinically relevant BM concentrations while presenting the detection limit of 0.27 μM min−1. The optical performances were associated with the conventional standardized approach in terms of recovery values (85–98%), thus presenting sufficient adaptability to complex matrix analysis as whole milk.
Narsingh R. Nirala
Giorgi Shtenberg
Bovine mammary gland is susceptible to numerous bacterial infections resulting in inflammatory disease condition of bovine mastitis (BM) with a staggering economic impact on the dairy industry worldwide. Early BM detection is crucial for infection control within the dairy herd, which can be alleviated by antimicrobial therapy. N-acetyl-β-D-glucosaminidase (NAGase) is a prominent BM inflammatory biomarker secreted onto the blood circulation upon pathogenesis and then released into milk, capable of separating healthy quarters from subclinical and clinical BM cases. Herein, we report a sensitive, cost-effective and handy-to-use BM severity assay based on NAGase inherent content found in whole milk samples. Silver-coated porous Si (Ag-PSi) Fabry–Pérot interferometers were employed for quantifying the lysosomal activity in different milk qualities using surface-enhanced Raman spectroscopy (SERS). The optical response was proportional to the occurring pathogenesis induced by predominant bacteria found in dairy farms at different somatic cell levels. The optimized Ag-PSi SERS substrates were utilized for quantitative analysis of NAGase levels found at clinically relevant BM concentrations while presenting the detection limit of 0.27 μM min−1. The optical performances were associated with the conventional standardized approach in terms of recovery values (85–98%), thus presenting sufficient adaptability to complex matrix analysis as whole milk.