Comparison Between the Conventional Bacterial Culture and the Real Time PCR in Identifying the Dairy Cow Mastitis Causative Agents

Mastitis is a prevalent and costly disease in dairy farms. This study compares routine in- vitro microbial culture and real time PCR (rtPCR) in identifying mastitis causative agents. The diagnosis of any intramammary infection is based on the identification of the infectious agent and the time taken by the identification method plays an important role in disease management. Out of 9,000 Holstein milking cows in the herd, eighty-three milk samples were aseptically taken from cows with clinically verified mastitis in the first quarter of 2019. The CHROMagar™ Mastitis kit was used in microbial culture for both gram-negative and gram-positive bacteria, along with Edwards Medium HiVeg Base, Modified Medium. On the other hand, the King Fisher™ Duo Prime Purification System, the Mag MAX™ CORE Nucleic Acid Purification Kit, and VetMAX™ Masti Type Kit were utilized for each sample to conduct the rtPCR experiment and DNA extraction. All data were analyzed by the Chi-square tests. The ROC curves showed that rtPCR was more effective than the bacterial culture approach in a comparative analysis (chi-square = 0.27, P = 0.59) and (AUC = 0.653). With its high analytical accuracy and potential for application in regular bovine intramammary infection testing services, the rtPCR assay is a highly promising test.