Comparative Efficacy of Horse and Chicken Serum for the In Vitro Cultivation ofClinical Isolates.

Abstract

is an important respiratory pathogen in swine, yet optimal culture conditions for high-yield propagation remain undefined. This study compared horse serum (HS) and chicken serum (CS) at graded concentrations (10%, 20%, 30%) for their ability to support in vitro growth of four clinicalisolates (strains A, B, C, and D). Cultures were prepared in modified Friis medium, and growth performance was assessed by final titer (color changing unit, CCU/mL) and time-to-detection at 10and 10CCU/mL. All media supported growth, but HS consistently outperformed CS in both yield and growth kinetics. The highest titers (10CCU/mL) and shortest detection times (3.6-6 days) were observed in 20% HS for most strains. Increasing HS concentration to 30% reduced yield for several strains, suggesting a concentration-dependent inhibitory effect. CS demonstrated limited but strain-dependent growth support, with comparable performance to HS for strain B at lower thresholds. These findings identify 20% HS as an optimal supplement for efficientcultivation, while highlighting the potential of CS as a cost-effective alternative under certain conditions, with implications for diagnostic reagent production and vaccine development.